High Early Strength Fiber Reinforced...

SHRP-C-366

Mechanical Behavior of

High Performance Concretes, Volume 6

High Early StrengthFiber Reinforced Concrete

A. E. NaamanF. M. AlkhairiH. Hammoud

University of Michigan, Ann Arbor

Strategic Highway Research ProgramNational Research Council

Washington, DC 1993

SHRP-C-366ISBN 0-309-05618-7Contract C-205

Product No. 2014, 2023, 2024

Program Manager: Don M. HarriottProject Manager: lnam JawedProduction Editor: Cara J. Tate

Program Area Secretary: Carina S. Hreib

October 1993

key words:admixture

aggregatecompressive strengthdurability

fatiguefiber-reinforced concrete

flexural strengthhigh early strengthhigh-performance concretemodulus

portland cement concretetensile strengthtoughness index

Strategic Highway Research ProgramNational Academy of Sciences2101 Constitution Avenue N.W.

Washington, DC 20418

(202) 334-3774

The publication of this report does not necessarily indicate approval or endorsement of the findings, opinions,conclusions, or recommendations either inferred or specifically expressed herein by the National Academy ofSciences, the United States Government, or the American Association of State Highway and TransportationOfficials or its member states.

© 1993 National Academy of Sciences

I.SM/NAP/1093

Acknowledgments

The research described herein was supported by the Strategic Highway Research Program(SHRP). SHRP is a unit of the National Research Council that was authorized by section128 of the Surface Transportation and Uniform Relocation Assistance Act of 1987.

The overall research work was undertaken by a consortium of three universities, namely:North Carolina State University (prime contractor) with P. Zia (project director), S. Ahmad,and M. Lemming; the University of Michigan with A. E. Naaman (principal investigator);and the University of Arkansas with R. P. Elliot and J. J. Schemmel.

The research team received valuable support, counsel, and guidance from the Expert TaskGroup. The support and encouragement provided by Inam Jawed, SHRP project manager, isdeeply appreciated.

The authors of this report also would like to acknowledge the help of several collaboratorsin conducting various phases of the experimental investigation. They include M. Harajli(visiting professor) and graduate students P. Strzyinski, I. Khayyat, B. Campbell, S. M.Jeong, and J. Alwan. Opinions expressed in this report are those of the authors and do notnecessarily reflect the views of SHRP.

oo°

111

Contents

Acknowledgments ................................................. iii

List of Figures ..................................................... ix

List of Tables ................................................... xvii

Preface ......................................................... xix

Abstract ......................................................... 1

Executive Summary ................................................. 3

1 Introduction .................................................... 7

1.1 SHRP C-205: Mechanical Behavior of High Performance Concretes ........ 7

1.1.1 Project Overview ....................................... 7

1.1.2 Definition of High Performance Concrete (HPC) ................. 8

1.2 High Early Strength Fiber Reinforced Concrete (HESFRC) ............. 10

1.2.1 Summary

1.2.2 Organization of This Report .............................. 111.3 References ............................................... 13

2 Objectives and Scope ............................................ 15

3 Characterization of Constituent Materials ............................... 19

3.1 Cement ................................................. 19

3.2 Coarse Aggregates ......................................... 19

3.3 Fine Aggregates ........................................... 213.4 Mineral Admixtures ........................................ 21

3.5 Chemical Admixtures ....................................... 21

3.6 Other Admixtures .......................................... 21

3.7 Fibers .................................................. 21

4 Mixture Proportions ............................................. 23

4.1 Development Phase ............. •............................ 234.2 Production Phase .......................................... 23

5 Mixing and Curing Procedures ...................................... 31

5.1 Mixing Procedure .......................................... 31

5.2 Curing Procedure .. ........................................ 32

5.3 Properties of Fresh Mix ...................................... 32

6 Compression Tests .............................................. 37

6.1 Experimental Program ....................................... 37

6.2 Test Apparatus and Procedure ................................. 37

6.3 Data Analysis and Test Results ................................ 47

6.3.1 Stress versus Strain Response with Time ..................... 49

6.3.2 Stress versus Strain Response: Comparison Between Series ........ 56

6.3.3 Compressive Strength .................................. 616.3.4 Elastic Modulus ...................................... 66

6.4 Conclusions .............................................. 69

6.4.1 Stress-Strain Response in Compression ...................... 696.4.2 Elastic Modulus ...................................... 71

6.5 Recommendations .......................................... 72

6.6 References ............................................... 74

7 Bending Tests .......... ....................................... 75

7.1 Experimental Program ....................................... 75

7.2 Test Apparatus and Procedure ................................. 79

7.2.1 Apparatus ........................................... 79

7.2.2 Definition of Toughness Index ............................ 79

7.3 Data Analysis and Test Results ................................ 84

7.3.1 Load versus Deflection and Strain Capacity Response with Time .... 84

7.3.2 Load versus Deflection Response: Comparison Between Series ...... 94

7.3.3 Modulus of Rupture or Maximum Flexural Strength ............ 1017.4 Conclusions ............................................ 111

vi

7.5 Recommendations ......................................... 114

7.5.1 Recommendations Based on Strength Criteria ................. 114

7.5.2 Recommendations Based on Energy Absorption (Toughness) Criteria 1157.6 References .............................................. 117

8 Splitting Tensile Tests ........................................... 119

8.1 Experimental Program ...................................... 119

8.2 Test Apparatus and Procedure ................................ 119

8.3 Data Analysis and Test Results ............................... 125

8.4 Conclusions ............................................. 130


8.6 References .............................................. 136

9 Fatigue Tests ................................................. 137

9.1 Experimental Program ...................................... 137

9.2 Test Apparatus and Procedure ................................ 139

9.3 Data Analysis and Test Results ............................... 143

9.3.1 Dynamic Modulus of Elasticity ........................... 146

9.3.2 Fatigue Life and Endurance Limit ......................... 146

9.3.3 Fatigue Life and Endurance Limit: Comparison with

Other Investigations ................................ 147

9.3.4 Hysteretic Load versus Deflection Response .................. 149

9.3.5 Load versus Tensile Strain Capacity ....................... 1519.4 Conclusions ............................................. 156


9.6 References .............................................. 157

10 Summary and Recommendations ................................... 159

10.1 Compression Tests ........................................ 159

10.2 Bending Tests ........................................... 160

10.2.1 Recommendations Based on Strength Criteria ................ 161

10.2.2 Recommendations Based on Energy Absorption

(Toughness) Criteria ............................... 161

10.3 Splitting Tensile Tests ...................................... 162

10.4 Fatigue Tests ............................................ 163

10.5 Recommendations for Future Research .......................... 163

vii

Bibliography .................................................... 165

Appendix A: Compression Tests ...................................... 171

Appendix B: Bending and Tensile Tests ................................. 251

Apppendix C: Fatigue Tests ......................................... 277

o,,VIII

List of Figures

Fig. 4.1 - Flowchart Showing Classification of the Mixes Used ............................... 24

Fig. 4.2 - Mix ID Code .................................................................................................... 26

Fig. 6.1 - Flowchart of the Compression Experimental Program .................................. 39

Fig. 6.2 - Specimen ID Code ........................................................................................... 40

Fig. 6.3 - Test Set-up for Measurement of Elastic Modulus ........................................... 42

Fig. 6.4 - Test Set-up Used to Determine the Stress-Strain Response

in Compression ............................................................................................... 43

Fig. 6.5 - Stress vs. Strain Response of Control Mix with Time .................................... 50

Fig. 6.6 - Effect of Cylinder Size on the Stress-Strain Response

of the Control Mix ........................................................................................... 50

Fig. 6.7 - Stress vs. Strain Response of Mix A1%S3 with Time ................................... 51

Fig. 6.8 - Effect of Cylinder Size on the Stress-Strain Response of Mix A1%S3 .......... 51

Fig. 6.9 - Stress vs. Strain Response of Mix A2%S3 with Time ................................... 53

Fig. 6.10 - Effect of Cylinder Size on the Stress-Strain Response of Mix A2%S3 ........ 53

Fig. 6.11 - Stress vs. Strain Response of Mix A 1%S5 with Time ................................. 54

Fig. 6.12 - Effect of Cylinder Size on the Stress-Strain Response of Mix A1%S5 ........ 54

Fig. 6.13 - Stress vs. Strain Response of Mix A l%P0.75 with Time ............................ 55


of Mix AI %P0.75 ......................................................................................... 55

Fig. 6.15 - Stress vs. Strain Response of Mix A2%P0.75 with Time ............................ 57


of Mix A2%P0.75 ......................................................................................... 57

Fig. 6.17 - Stress vs. Strain Response of Mix AI%S3S5 with Time ............................. 58

ix

Fig. 6.18 - Effect of Cylinder Size on the Stress-Strain Responseof Mix A 1%S3S5 .......................................................................................... 58

Fig. 6.19 - Stress vs. Strain Response of Mix A2%S3S5 with Time ............................. 59


of Mix A2%S3S5 ......................................................................................... 59

Fig. 6.21 - Effect of Fiber Type on the 1 Day Stress-Strain Response (Vf=l%) ........... 60

Fig. 6.22 - Effect of Fiber Type on the 28 Day Stress-Strain Response (Vf=l%) ......... 60

Fig. 6.23 - Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=l%) ........... 62

Fig. 6.24 - Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=2%) ........... 62

Fig. 6.25 - Compressive Strength, f'c vs. Time (Vf=l%) .............................................. 64

Fig. 6.26 - Compressive Strength, f'c vs. Time (Vf=2%) .............................................. 64

Fig. 6.27 - Compressive Strength, f'c _,s.Time, 50/50 Steel Fibers, (Vf=l%) ............... 65

Fig. 6.28 - Compressive Strength, f'c _,s.Time, Polypropylene Fibers, (Vf=l%) ......... 65

Fig. 6.29 - Elastic Modulus, Ec vs. x/f'c ........................................................................ 67

Fig. 6.30 - Elastic Modulus, Ec vs. Time, (Vf=l%) ....................................................... 68

Fig. 6.31 - Elastic Modulus, Ec vs. Time, (Vf=2%) ....................................................... 68

Fig. 7.1 - Flowchart of the Flexural Experimental Program ........................................... 77

Fig. 7.2 - Specimen ID Code ........................................................................................... 78

Fig. 7.3 - Sketch of the Test Set-up for Flexural Tests ................................................... 80

Fig. 7.4 - Test Set-up for the Flexural Tests ................................................................ 81

Fig. 7.5 - Instrumentation Used for the Flexural Tests ................................................... 82

Fig. 7.6 - Toughness Index in Bending: top) Definition for an Elastic Perfectly

Plastic Response; bottom) Typical Curves for FRC ....................................... 83

Fig. 7.7 - Effect of Time on Load vs. I-)eflection Response,

50/50 Steel Fibers, (Vf=1%) ........................................................................... 88

Fig. 7.8 - Effect of Time on Load vs. Deflection Response,

30/50 Steel Fibers, (Vf=1%) ........................................................................... 88


30/50 Steel Fibers, (Vf=2%) ........................................................................... 89


1/2" Polypropylene Fibers, (Vf--0.15%) ....................................................... 89

Fig. 7.11 - Effect of Time on Load vs. Strain Capacity Response,

1/2" Polypropylene Fibers, (Vf=0.15%) ...................................................... 90


1/2" Polypropylene Fibers, (Vf=1%) ............................................................ 90


1/2" Polypropylene Fibers, (Vf=2%) ............................................................ 91


30/50 + 50/50 Steel Fibers, (Vf=2%) ............................................................ 92


30/50 + 50/50 Steel Fibers, (Vf=2%) ............................................................ 92


Latex, 30/50 + 50/50 Steel Fibers, (Vf-1%) ................................................. 93


Latex, 30/50 + 50/50 Steel Fibers, (Vf=l%) ................................................. 93

Fig. 7.18 - Load vs. Deflection Response for Different Mixes, 1 Day,

Plain FRC, (Vf=1%) ..................................................................................... 95

Fig. 7.19 - Load vs. Strain Capacity Response for Different Mixes, 1 Day,

Plain and Hybrid FRC, (Vf--l%) .................................................................. 95

Fig. 7.20 - Load vs. Deflection Response for Different Mixes, 28 Days,

Plain FRC, (Vf=1%) ..................................................................................... 96

Fig. 7.21 - Load vs. Strain Capacity Response for Different Mixes, 28 Days,

Plain and Hybrid FRC, (Vf=1%) .................................................................. 96

Fig. 7.22 - Load vs. Deflection Response for Different Mixes, 1 Day,

Plain FRC, (Vf=2%) ..................................................................................... 98

xi

Fig. 7.23 - Load vs. Strain Capacity Response for Different Mixes, 1 Day,

Plain and Hybrid FRC, (Vf-2%) .................................................................. 98

Fig. 7.24 - Load vs. Deflection Response for Different Mixes, 28 Days,

Plain FRC, (Vf=2%) ..................................................................................... 99

Fig. 7.25 - Load vs. Strain Capacity Response for Different Mixes, 28 Days,

Plain and Hybrid FRC, (Vf=2%) .................................................................. 99

Fig. 7.26 - Effect of Additive on Load vs. Deflection Response, 1 Day,

50/50 Steel Fibers, (Vf=l%) ......................................................................... 100

Fig. 7.27 - Effect of Additive on Load vs. Strain Capacity Response, 1 Day,

50/50 Steel Fibers, (Vf=1%) .......................................................................... 100

Fig. 7.28 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=l%) ................... 102

Fig. 7.29 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=2%) ................... 102

Fig. 7.30 - Toughness Index 15and I10vs. Time, 30/50 Steel Fibers, (Vf=l%) ............. 105

Fig. 7.31 - Toughness Index I5 and I10vs. Time, 30/50 Steel Fibers, (Vf--2%) ............. 105

Fig. 7.32 - Toughness Index 15and II0 vs. Time, 50/50 Steel Fibers, (Vf=l%) ............. 106

Fig. 7.33 - Toughness Index I5 and 110vs. Time,

1/2" Polypropylene Fibers, (Vf=l%) ............................................................ 106

Fig. 7.34 - Toughness Index I5 and I10vs. Time, 50/50 Steel Fibers,

Latex, (Vf=1%) ............................................................................................. 107

Fig. 7.35 - Toughness Index I5 and I10vs. Time, 30/50 Steel + 50/50 Steel

Fibers, Latex, (Vf=1%) ................................................................................. 107

Fig. 7.36 - Toughness Index I5 and I10 vs. Time, 1/2" Polypropylene Fibers,

Latex, (Vf=l%) ............................................................................................. 108

Fig. 7.37 - Toughness Index I5 and 110vs. Time, 50/50 Steel Fibers,

Silica Fume, (Vf--1%) ................................................................................... 108

Fig. 7.38 - Toughness Index I20-co vs. Time for Different Mixes, (Vf=l%) ................. 109

Fig. 7.39 - Toughness Index I20 -Ist-CR vs. Time for Different Mixes, (Vf--l%) ........... 109

Fig. 7.40 - Toughness Index I.5-co vs. Time for Different Mixes, (Vf=l%) .................. 110

xii

Fig. 7.41 - Toughness Index I5 -lst-CR vs. Time for Different Mixes, (Vf-l%) ............ 110

Fig. 7.42 - Toughness Index I5 -co vs. Time for Different Mixes, (Vf=2%) .................. 112

Fig. 8.1 - Flowchart of the Splitting Tensile Experimental Program .............................. 121

Fig. 8.2 - Specimen I19Code ........................................................................................... 122

Fig. 8.3 - Set-up for Splitting Tensile Test ..................................................................... 123

Fig. 8.4 - Specimen Positioning for the Splitting Tensile Test ....................................... 124

Fig. 8.5 - Modulus of Rupture fr vs. ",1f'c'for Different Mixes ...................................... 128

Fig. 8.6 - Splitting Tensile Strength fspt vs. _/f'c'for Different Mixes .......................... 128

Fig. 8.7 - Splitting Tensile Strength fspt for Different Mixes, 1Day, (Vf=l%) .............. 129

Fig. 8.8 - Splitting Tensile Strength fspt for Different Mixes, IDay, (Vf--2%) .............. 129

Fig. 8.9 - Splitting Tensile Strength fspt for Different Mixes, 1Day,

Latex, (Vf=1%) ............................................................................................... 131

Fig. 8.10 - Splitting Tensile Strength fspt for Different Mixes, 1Day,

Silica Fume, (Vf=1%) ................................................................................... 131

Fig. 8.11 - Compressive Strength f'c for Different Mixes, 1Day, (Vf=l%) ................... 132

Fig. 8.12 - Compressive Strength f'c for Different Mixes, 1Day, (Vf=2%) ................... 132

Fig. 8.13 - Compressive Strength f'c for Different Mixes, 1Day, Latex, (Vf=l%) ........ 133

Fig. 8.14 - Compressive Strength f'c for Different Mixes, 1Day,

Silica Fume, (Vf=l%) ................................................................................... 133

Fig. 9.1 - Experimental Program for Flexural Fatigue .................................................... 138

Fig. 9.2 - Testing Machine Used in Flexural Fatigue Tests ............................................ 140

Fig. 9.3 - Instrumentation and Test Set-Up for Flexural Fatigue Tests ......................... 141

Fig. 9.4 - Specimen #10 after Fatigue Failure, Mix A2%S3,

Load Range 10%-70% .................................................................................... 144

Fig. 9.5 - Specimen #15 after Fatigue Failure, Mix A2%S3S5,

Load Range 10%-90% .................................................................................... 144

Fig. 9.6 - Modulus of Rupture versus Dynamic Modulus .............................................. 148

xiii

Fig. 9.7 - Number of Cycles to Failure versus Maximum Applied Load ....................... 148

Fig. 9.8 - Load versus Deflection Hysteretic Response of Specimen #16

under Fatigue Loading .................................................................................... 150


under Fatigue Loading .................................................................................... 150


under Fatigue Loading .................................................................................. 152

Fig. 9.11 - Variation of Deflection versus Number of Cycles for Specimen #21 ........... 152



Fig. 9.14 - Load versus Deflection Response after Fatigue: Loading

for Specimen #17 .......................................................................................... 154

Fig. 9.15 - Variation of Strain versus Number of Cycles for Specimen #21 .................. 154

Fig. 9.16 - Variation of Strain versus Number of Cycles fi_rSpecimen #10 .................. 155

Fig. A.1 - A.79: Stress versus Strain Curves for each Series and its Representative

Average Curve ............................................................................. 188

Fig. A.80 - A.94: Stress versus Strain Response with Time and Effect of Cylindrical

Size .............................................................................................. 228

Fig. A.95 - A.104: Stress versus Strain response for Different Series ........................ 236

Fig. A.105 - A. I I 1: Compressive Strength f'c ............................................................. 241

Fig. A.112 - A.120: Elastic Modulus ............................................................................ 245

Fig. B. 1 - B. 16: Graphs of Load versus Deflection and Strain Capacity

Response with Time ..................................................................... 257

Fig. B.17 - B.20: Load versus Deflection Response for Different Series ................. 265

Fig. B.21 - B.29: Modulus of Rupture fr .................................................................. 267

Fig. B.30 - B.39: Toughness Indices ........................................................................ 272

Fig. C.1 - C.7 • Load versus Deflection Hysteretic Kesponse under

Fatigue Loading ............................................................................ 278

xiv

Fig. C.8 - C12 : Variation of Deflection versus Number of Cycles ....................... 282

Fig. C. 13 : Load versus Deflection Response after Fatigue Loading ............. 284

Fig. C. 14 - CI 8: Variation of Strain versus Number of Cycles ............................... 285

Fig. C. 19 - C20: Load versus Strain Response after Fatigue Loading .................... 288

Fig. C.21 - C30: Load versus Strain Response under Static Loading ..................... 289

Fig. C.31 - C38: Load versus Strain Response under Static Loading ..................... 294

List of Tables

Table 1.1 - Criteria for HPC ................................................................................................ 9

Table 3.1 - Aggregate Gradation for the Coarse Aggregates (Gravel) .............................. 20

Table 3.2 -Aggregate Gradation for the Fine Aggregates (Sand) ..................................... 20

Table 3.3 - Properties of Fibers Used ................................................................................ 20

Table 4.1 -Design Proportions for Mix Series A, B, and C ......................................... 27

Table 4.2 - Matrix Composition for Mix Series A, B, and C

(Proportions are given by weight) .................................................................. 28

Table 4.3 - Typical Fiber Content by Weight as Used in This Study ................................ 28

Table 5.1 - HESFRC Plastic Properties ............................................................................. 33

Table 6.1 - Number of Specimens Tested ......................................................................... 38

Table 6.2 - Summary of the Average Values of f'c and Ec

Obtained for Each Time Series .................................................................... 44

Table 7.1 - Number of Specimens Tested ......................................................................... 76

Table 7.2 - Summary of Main Flexural Test Results ........................................................ 85

Table 8.1 - Number of Specimens Tested ....................................................................... 120

Table 8.2 - Average f'c, fr, and fspt Values for Each Time Series ................................ 126

Table 9.1 - Results of Dynamic Modulus and Modulus of Rupture Tests ...................... 142

Table 9.2 - Results of Fatigue Tests ................................................................................ 145

Table A. 1 - A. 16: Tables of Values of f'c and Ec for Each Specimen and Average

Values and Standard Deviation of Each Series ............................. 172

Table B.1 - Strength Results for Each Individual Specimen ............................................ 252

xvii

Preface

The Strategic Highway Research Program (SI-IRP)is 5-year nationally coordinated research

effort initiated in 1988 at a cost of $150 million. This highly focused and mission-oriented

program originated from a thorough and probing study* of deterioration of the nation's

highway and bridge infrastructure. The study documented the need for a concerted research

effort to produce major innovations for increasing the productivity and safety of the nation's

highway system; further, it recommended that the research effort be focused on six critical

areas in which the nation spends most of the $50 billion used for roads each year, and thus

technical innovations would have the potential for substantial payoffs. The six critical research

areas were as follows:

• Asphalt Characteristics

• Long-Term Pavement Performance• Maintenance Cost Effectiveness

• Concrete Bridge Component Protection

• Cement and Concrete

° Snow and Ice Control

When SHRP was implemented, the two research areas of Concrete Bridge Component

Protection and Cement and Concrete were combined under a single program directorate of

Concrete and Structures. Likewise, the two research areas of Maintenance Cost-Effectiveness

and Snow and Ice Control were also combined under another program directorate of Highway

Operations.

*America's Highways: Accelerating the Search for hmovatio,s. Special Report 202, Tr,'mspormtion Rese,'u'chBorn-d, Nation,,d Rese,'u'ch Council, Washington. DC 1984.

xix

Abstract

This study provides an extensive databasc and a summary of a comprehensive experimental

investigation on the fresh state and mechanical properties of high early strength fiber reinforced

concrete(HESFRC).The controlhighearlystrength(HES)concreteusedforfiberaddition

andtheresultingHESFRC arcdefinedasachievingatargetminimum compressivestrengthof

5ksi(35MPa) in24hours,asmeasuredfrom4x 8-in.(100x 200-ram)cylinders.Fresh

HESFRC propertiestestedincludeaircontent,workability(bytheinvcrtcdslumptest),

temperature,andplasticunitweight.Testsonthemechanicalpropertiesincludecompressive

strength,elasticmodulus,flcxuralstrength,splittingtensilestrength,andfatiguelife.Sixteen

differentcombinationsofparameterswereinvestigated;thevariableswerethevolumefraction

offibers(1% and2%),thetypeoffiber(steel,polypropylene),thefiberlengthoraspectratio,

andtheadditionoflatexorsilicafumetothemix.Optimalmixesthatsatisfiedtheminimum

compressivestrengthcriterion,andshowedcxceUcntvaluesof modulusofrupture,toughness

indicesinbending,andfatiguelifeinthecrackedstate,arcidentified.Potentialapplicationsin

construction,repair,andrehabilitationoftransportationstructuresaresuggested.

Executive Summary

The main objectives of this experimental study were (I) to establish a consistent and

comprehensive database on high early strength fiber reinforced concrete (HESFRC), (2) to

document and synthesize information on the properties of the fresh mix and the mechanical

properties of the hardened composite, and (3) to develop some practical recommendations for

use of HESFRC by the profession. It should be noted that although several thousand

investigations have dealt with fiber reinforced concrete, none has included such a complete

range of tests (from the fresh state to the hardened composite) and tested such a range of

parameters as this study, and none has provided the same consistent testing procedures

throughout. This experimental investigation followed an initial evaluation of existing

knowledge in the field as summarized in an earlier state-of-the-art report and an annotated

bibliography on high performance fiber reinforced concrete.

HESFRC was dcf'med as achieving a minimum target compressive strength of 5 ksi (35 MPa)

in 24 hours. Since the minimum strength criterion could be satisfied by the control specimens

without fibers, and since in current applications of fiber rcinforced concrete for pavements only

low fiber contents (0.10% to I% by volume of concrete) are used, it was decided to explore

and documcnt a higher range of fiber content (1% and 2% by volume of concrete). The main

intent was to achieve, in addition to the minimum specified compressive strength, a post-

cracking strength in bending (i.e., a modulus of rupture) higher than the cracking strength so

as to minimize crack widths and ensure a sufficient resistance to repeated loads after cracking.

Several properties of HESFRC were investigated, including, for the fresh mix, the air content,

workability (by the inverted slump test), temperature, and unit weight and, for the hardened

composite, the compressive, bending, tensile, and fatigue properties. Particular attention was

given to recording not only key properties such as compressive strength, elastic modulus, and

modulus of rupture, but also the entire stress-strain response in compression and load-

deflection curve in bending so as to provide additional information on strain capacity and

complete data for future reference. Also, values of toughness indices at different deflections

were calculated from the load-deflection curves.

Sixteen different combinations of parameters were investigated for each type of test. Moreover,

for the bending tests only, one additional mix containing 0.15% by volume of polypropylene

fibers was also tested (at the request of the project Expert Task Group) to simulate current low-

fibercontent mixes used in some applications, such as slabs on grade.

The main parameters included (1) three different matrix mixes (one control, one with silica

fume, and one with latex), (2) two different volume fraction of fibers (1% and 2%), (3) two

fiber materials (steel and polypropylene), 114)two steel fiber lengths corresponding to aspect

ratios of 60 and 100 respectively, and (5) hybrid mixes containing either an equal amount of

steel and polypropylene fibers or an equal amount of steel fibers of different lengths. The

compression and the bending tests also included a time variable; the compressive properties

were measured at ages 1, 3, 7, and 28 days, and the bending properties at ages 1, 7, and 28

days, respectively. Information from the compression tests comprised the compressive

strength, the elastic modulus, and the strain capacity. Also, the effect of specimen size, i.e.,

4 x 8-in. (100 x 200-mm) cylinders versus 6 x 12-in. (150 x300-mm) cylinders, was

documented. Information from the bending tests included the modulus of rupture and the

toughness indices as per ASTM standards.

The main conclusions are as follows.

OveraLl, the additions of 2% by volume of 30/50 hooked steel fibers (or 2% of an equal

combination of 30/50 and 50/50) gave optimal composite properties in the fresh and hardened

state. It caused significant increases in the compressive strength, modulus of rupture, splitting

tensile strength, toughness indices, ductility (or strain capacity), and fatigue limit when

compared with all other HESFRC mixes, as well as with the control mix without fibers. In

comparison with the control mix, average increases of 30% in compressive strength, 270% in

modulus of rupture, 250% in splitting tensile strength, and predicted endurance limit in

bending of 65% of ultimate while in the cracked state were observed. Moreover, values of

toughness indices 15 and I10 as high as 30 and 60 imply energy absorption capacities at least30 to 60 times that of the control mix without fibers.

Next in performance were the mixes containing 1% by volume: of 50/50 or 30/50 + 50/50

hooked steel fibers; both mixes performed similarly in terms of compressive strength, elastic

modulus, modulus of rupture, and splitting tensile strength. In comparison with the control

mix without fibers, these mixes led to little change in compressive strength, but, on average,

increased the modulus of rupture and splitting tensile strength by 200% and 173%

respectively. Here toughness indices as high as 9 for 15 and 23 for I10 were observed.

In general, the property affected most by the addition of fibers, be it steel or polypropylene

fibers, is the toughness index in bending. Toughness indices 15 and I10 generally exceeded 5

and 10, respectively, when 1% fibers by volume was added. Thus, a substantially improved

energy absorption capacity (which can be translated in improved impact energy) seems to be

the most evident benefit of adding fibers to HES concretes.

Mixes containing 1% or 2% by volume of polypropylene (PP) fibers showed deterioration in

the compressive stress-strain response when compared with the control mix. The mix with 2%

by volume of PP fibers was more difficult to mix, led to larger a volume of entrapped air, and

resulted in poorer properties than the mix with 1% PP fibers by volume. Therefore, the use of

polypropylene fibers only to improve compressive strength and elastic modulus is not

recommended. However, as mentioned above, polypropylene fibers did markedly improve

the toughness index of the composite.

Although latex improved the workability of HESFRC mixes and their 28-day compressive

strength, its use is not desirable for the sole purpose of improving early age properties.

However, it should be observed that latex is generally used to improve the bond between new

and old concrete in repair applications, and is known to improve durability. These very

important properties were not tested in this investigation.

The addition of silica fume does not significantly affect the 1-day compression, bending, and

tensile properties of HESFRC composites. However, properties at later ages were improved

similarly to those of plain concrete.

Hybrid mixes with steel andpolypropylene fibers did not fare as well as all-steel fiber mixes

with the same total fiber content by volume.

The compressive strength of HESFRC mixes obtained from 6 x 12-in. (150 x 300-mm)

cylinders was, on average, 3.9% smaller than that obtained from 4 x 8-in. (100 x 200-mm)

cylinders.

Given the properties observed in this investigation, it can be inferred that high early strength

fiber reinforced concret* (HESFRC) containing fibers (pardc_arly hooked steel fibers) in 1%

to 2% by volume, can be used for several highway-related applications. They include, (1)

repair type applications for which early strength and toughness (energy absorption and impact

properties) are needed, such as for potholes, bridge decks, overlays, pavement joints, piers,

and runways; and (2) applications in new structures, particularly bridge decks, pavements,

bridge piers, piles, reusable median barriers, taxiways, and runways. These are applications

for which the specific advantages of HESFRC compared with HES concrete without fibers are

needed such as its increased resistance to cracking, its increased toughness (i.e., energy

absorption capacity against dynamic and impact Ioadings and resistance to damage), its

increased ductility, its smaller crack widths (thus reducing penetration of chlorides), and its

increased fatigue. Moreover, HESFRC can be used in conventional reinforced and

pres_essed concrete structures to replace the plain concrete matrix. In such cases, the use of

HESFRC is expected to lead to substantially improved structural ductility, better hysteretic

response under cyclic load reversals, better bonding of the reinforcing bars, improved

resistance of the concrete cover to spaUing, improved shear resistance, savings in stirrups, and

overall improved energy absorption capacity of the structure.

6

1

Introduction

1.1 SHRP C-205: Mechanical Behavior of High PerformanceConcretes

1.1.1 Project Overview

One of the eleven projects in the program areaof Concrete and Structures is SHRP C-205

entitled "Mechanical Behavior of High Performance Concretes", which is a 4-year study

initiated on March 1, 1989. There were three generalobjectives of the project:

(1) To obtain needed information to fill gaps in the present knowledge;

(2) To develop new, significantly improved engineering criteria for the mechanical

properties and behavior of high performance concretes; and

(3) To provide recommendations and guidelines for using these concretes in highway

applications according to the intended use, required properties, environment, and

service.

Both plain and fiber reinforced concretes were included in the study. The research f'mdings axe

presented in a series of project reports in six separate volumes, Mechanical Properties of High

Performance Concretes, as follows:

Volume 1 Summary Report

Volume 2 Production of High Performance Concrete

Volume 3 Very Early Strength (VES) Concrete

Volume 4 High Early Strength (HES) Concrete

Volume 5 Very High Strength (VHS) Concrete

Volume 6 High Early Strength Fiber Reinforced Concrete(HESFRC)

The discussion of the development and production of high early strength fiber reinforced

concrete (HESFRC) is covered in this report (Volume 6), and a brief summary for field mixing

and handling is provided in the overall summary report (Volume 1).

1.1.2 Definition of High Performance Concrete (HPC)

In general terms, high performance concrete (HPC) may be defined as any concrete that

provides enhanced performance characteristics for a given application. Concretes that provide

substantially improved resistance to environmental influences, high durability under service

conditions, extraordinary properties at early ages, or substantially enhanced mechanical

properties, are potential HPCs. These concretes may contain materials such as fly ash, ground

granulated slags, silica fume, fibers, chemical admixtures, and other materials, individually or

in various combinations [3,4].

Engineers are making increasing use of HPCs for a variety of highway applications, including

new construction, repairs, and rehabilitation. Higher-strength concrete can make possible more

structural design flexibility and provide more options. Improved early age properties of

concrete can facilitate construction and rehabilitation tasks and improve qnality. Higher

durability can increase the service life, which may reduce life cycle cost.

For the purpose of this research program, HPC is defined in terms of certain target strength

and durability criteria as specified in Table i.1. Additional target criteria for high early strength

fiber reinforced concrete (HESFRC) are explained in the next .section.

In this definition, the target minimum strength should be achieved in the specified time after

water is added to the concrete mixture. The water/cement ratio (W/C) is based on all

cementitious materials. The minimum durability factor should be achieved after 300 cycles of

freezing and thawing according to ASTM C 666 (procedure A) [i].

Table 1.1 - Criteria for HPC

Category of HPC Minimum Maximum Minimum FrostCompressive Water/Cement DurabilityStrength Ratio Factor

Very Early Strength (VES)

Option A 2,000 psi (14 MPa) 0.40 80%(with Type III cement) in 6 hours

Option B 2,500 psi (17.5 MPa) 0.29 80%(with Pyrament, PBC-XT in 4 hourscement)

High Early Strength 5,000 psi (35 MPa) 0.35 80%(HES) in 24 hours

(with Type III cement)

Very High Strength 10,000 psi (70 MPa) 0.35 80%(VHS) in 28 days

(with Type HI cement)

These working definitions of HPC were adopted after several important factors were

considered with respect to the construction and design of highway pavements and structures.

The rationale for the selection of the various limits can be found in the project summary report

(Volume 1).

The strength criterion for very early strength (VES) concrete was originaUy defined by the

researchers of this project as that of option B, with no particular reference to the type of cement

(special cement if needed) to be used. However, in the interest of establishing an alternative

with portland cement as the binding material, the strength criterion of option A was adopted

with the recommendation of the Expert Task Group of the project.

1.2 High Early Strength Fiber Reinforced Concrete (HESFRC)

1.2.1 Summary

This report, volume 6 of the SHRP C-205 series of reports, presents the results of an extensive

experimental investigation on the properties of high early strength fiber reinforced concrete

(HESFRC) in both the fresh and hardened states. Like high early strength (HES) concrete,

HESFRC was defined as achieving a minimum target compressive strength of 5 ksi (35 MPa)

in 24 hours. Since the minimum-strength cliterion could be satisfied with the control specimens

without fibers, and since in current applications of fiber reinforced concrete for pavements only

low fiber contents (0.10% to 1% by volume of concrete) are used, it was decided to explore

and document a higher range of fiber content (1% and 2% by volume of concrete). The main

intent was to achieve, in addition to the minimum specified target compressive strength, a

postcracking strength in bending (i.e. a modulus of rupture) higher than the cracking strength

so as to minimize crack widths and insure a sufficient resistance to repeated loads after

cracking. This implied a minimum ductility behavior in bending otherwise not present in the

control specimens without fibers.

It should be noted that although several thousand investigations have dealt with fiber reinforced

concrete, none has included such a range of tests (from the fresh state to the hardened composite)

and tested such a range of parameters as in this study, and none has provided the same consistent

testing procedures throughout. This experimental investigation followed an initial evaluation of

existing knowledge in the field, as summarized in an earlier state-of-the-art report [3] and an

annotated bibliography on high performance fiber reinforced concrete (see Bibliography).

The fresh HESFRC properties measured included air content, workability (by the inverted

slump test), temperature, and plastic unit weight. Tests on the properties of the hardened

material included compressive strength, flexural strength, splitting tensile strength, and fatigue

life. In all 16 different mixes were investigated in depth; the variables included the volume

fraction of fibers, the type of fiber material, the fiber length, hybrid fiber composition, and theuse of silica fume or latex additives.

10

1.2.2 Organization of This Report

This report follows the same format used in the other volumes in this series. Chapters 2 to 5

describe the objectives and scope of this study, the characterization of the constituent materials

used, the mixture proportions, and the mixing and curing procedures, respectively.

Chapter 6 presents the properties of fresh HESFRC and the corresponding compressive

strength andelastic modulus with time. The effects of latex and silica fume on the compressive

stress-strain response and elastic modulus were also investigated and compared to plain

HESFRC. Two fiber types were used: hooked steel fibers and polypropylene fibers. For the

hooked steel fibers, two aspect ratios were examined corresponding to 30/50 fibers (i.e., 30

mm long and 0.5 mm in diameter) and 50/50 fibers (50 mm long and 0.5 mm in diameter).

Several combinations of both fiber types were examined using 1% and 2% by volume of the

concrete mix. The effects of latex and silica fume were also investigated and compared to plain

HESFRC. Test results include the overall stress-strain relationship, the compressive strength,

and the elastic modulus, all measured at.l, 3, 7, and 28 days. In all, more than 220 specimenswere tested.

Chapter 7 focuses on bending properties, namely the load versus deflection and load versus

strain capacity response in flexure. The strain was measured over a 4-in. gauge length along

the constant moment region on the tensile face of the beam tested. The same set of parameters

used for the compression tests was also selected for the bending tests. Test results include the

overall load versus deflection and load versus strain capacity relationships with time (measured

at 1, 7, and 28 days), the flexural strength with time, and the toughness indices, I5, I10, and

I20. The toughness indices were measured using two procedures, the ASTM C 1018 [2]

procedure, in which the reference deflection is taken as the deflection at cracking of the same

specimen under test, and a more accurate procedure in which the reference deflection is taken

as that of the control specimen without fibers.

Chapter 8 focuses on the tensile properties of HESFRC composites as obtained from the 1-day

splitting tensile strength. The splittting tensile strength is also compared with the modulus of

rupture (i.e., the tensile strength obtained from the bending tests) and compressive strength of

the same mixes. The same parameters used for the compression and bending tests wereinvestigated.

11

Chapter 9 focuses on the structural perfornmnce of HESFRC under flexural fatigue loading.

The test program was designed to provide data on the stiffness degradation, cracking

characteristics, and number of cycles to failure of HESFRC specimens subjected to flexural

fatigue loading. The parameters investigated were the stress range and the type of fibers used.

The specimens were subjected to three stress ranges, corresponding to 10% to 70%, 10% to

80%, and 10% to 90% of the static flexural strength obtained from sister specimens. The types

of fiber used were the 30/50 steel fibers and 50/50 steel fibers (see description above). Two

combinations of fibers were tested, with 2% fibers by volume of concrete. One set of

specimens was reinforced with 30/50 fibers, and another set was reinforced with an equal

combination of 30/50 and 50/50 fibers. No hybrid mix of steel and polypropylene fibers was

tested in fatigue, because the properties of such a mix in both static compression and bending

were not as good as those of the mixes reinforced with all steel fibers. The test results are

presented as plots of the load versus deflection and load versus tensile strain (in bending) for

different numbers of cycles. The fatigue life for the different load ranges is illustrated in a plot

of the maximum load level versus the number of cycles to failure (S-N diagram).

Finally, Chapter 10 provides an overall summary of the conclusions and recommendations

drawn from this investigation.

12

1.3 References

1. ASTM Standards. Test Method for Resistance of concrete to Rapid Freezing andThawing. ASTM C 666-90. Vol. 04.02. 1991.

2. ASTM Standards. Test Method for Flexural Toughness and First-Crack Strength ofFiber-Reinforced Concrete (Using Beam with Tbdrd-Point Loading). ASTM C 1018-89. Vol. 04.02. 1991.

3. Naaman, A.E., and M.H. Harajli. Mechanical Properties of High Performance FiberConcretes: A State-of-the-Art Report. Report no. SHRP-C/WP-90-004, SHRP,National Research Council, Washington, D.C. 1990.

4. Zia, P., M.L. Lemming,and S.H. Ahmad. High Performance Concretes: A State-of-the-Art Report.. Report no. SHRP-C-317. SHRP, National Research Council,Washington, D.C. 1991.

13

2

Objectives and Scope

The main objectives of this investigation were (1) to establish a consistent and comprehensive

database on the properties of high early strength fiber reinforced concrete (HESFRC), (2) to

document and synthesize information on the properties of the fresh mix and the mechanical

properties of the hardened composite, and (3) to develop some practical recommendations for

use of HESFRC by the profession.

High early strength (lIES) concrete, as defined in Section 1.1., when reinforced with fibers,

can be used for several highway related applications. They include (1) repair-type applications

for which early strength properties are needed such as for potholes, bridge decks, overlays,

pavement joints, and runways; and (2) applications in new structures particularly bridge decks,

pavements, median barriers, taxiways and runways. These are applications in which the

specific advantages of HESFRC compared with HES concrete without fibers are needed, such

as its increased resistance to cracking, its increased toughness (i.e., energy absorption capacity

against dynamic and impact loadings), its increased ductility, and its increased fatigue life.

Moreover, HESFRC can be used in reinforced and prestressed concrete structures to replace

the plain concrete matrix in these structures. In such cases, its use is expected to lead to

substantially improved structural ductility, better hysteretic response under cyclic load

reversals, better bonding of the reinforcing bars and prestressing tendons, improved resistance

of the concrete cover to spalling, smaller crack widths, and overall improved energy absorption

capacity of the structure.

The experimental investigation included several parts dealing with the properties of HESFRC:

the properties of the fresh mix (air content, workability by the inverted slump test, temperature,

15

and unit weight), and the compressive,bending, tensile, and fatigue propertiesof the hardened

composite. Only HESFRC is considered hc_'eand was defined as achieving a minimum target

compressive strength of 5 ksi (35 MPa) in 24 hours (see also section I. 1).

In relation to the part of the experimentalprogram dealing with the compression tests (chapter

6), the main objective was to study how using different types of fibers affected the plastic

properties of fresh fiber reinforced concrete,and the compressive properties of the hardened

fiber concrete composite. The following three major goals were sought: (1) to measure the

fresh properties of various HESFRC mixes, which include plastic unit weight, temperature,

workability (using the inverted cone test), and air content; 2) to obtain the complete

experimental stress-strain curves of various I-IESFRCmixes tested at 24 hours (1 day), and

then compare the results to tests performed at 3, 7, and 28 days; and (3) to determine the values

of strengthand modulus of elasticity of the composite and their variation with time between 1

day and 28 days.

The main objectivesof the bending tests (chapter7) were to investigatethe effects of using

different types of fibers in various amounts on the flexural properties of HESFRC, and to

determine which mix gives best values of modulus of rupture and/or toughness index. The

following major tasks were undertaken: (1) study the load versus deflection and load versus

straincapacity relationships at 1 day, and thencompare the results to similar tests performed at

7 and 28 days; (2) calculate the modulus of rapture of the hardened composite; and (3)

calculate the toughness indices of all mixes at different ages (1, 7, and 28 days), using for

reference (a) the area under the loadversus deflectioncurve up to first cracking of the

composite, as recommended by ASTM C 1018, and Co)the area under the load versusdeflection curve of the nonreinforced control mix.

The main objectiveof the part of this investigationdealingwith the splitting tensile tests

(chapter 8) was to investigate the splitting tensile strength,fspt, and corresponding compressive

strength,re, of all HESFRC mixes at 1 day. The results were also compared with the modulus

of rupture obtained from the bending tests (chapter7).

In chapter9, the overallobjectivewas to investigatethe behaviorof HESFRCunder flexural

fatigue loading, subjectedto differentstressranges andreinforcedwith two differentfiber

combinations. Thefibercombinationswere selected to correspondto mixes that gave best

compression,bending,and splitting-tensilepropertiesin the static tests. The maintasks can be

summarizedas follows: (1) to study the progressivestiffnessdegradationand cracking

behaviorof the HESFRC specimens byanalyzing their load versusdeflection and load versus

16

tensile strain curves; and (2) to obtainsome experimentaldata on the fatigue life of HESFRC

mixes under different stress ranges. The stress ranges tested corresponded to a load fluctuation

between a minimum of 10%of the flexural ultimate load, and a maximum of either 70%,80%

or 90%,respectively.

17

3

Characterization of Constituent Materials

3.1 Cement

Type HI high early strength cement was used. Cement was obtained from two different

suppliers: St. Marys Peerless Cement Company and Huron Cement Company, both in

Michigan. Type 1TIcement was needed to achieve the high early strength properties at 24

hours, as set by the criteria described in section 1.1.

3.2 Coarse Aggregates

The coarse aggregate used crushed limestone with a maximum size of 0.5 to 0.75 in. It was

purchased from Washtenaw Sand and Gravel Company in Ann Arbor, Michigan. The reason

for selecting a relatively small-size aggregate is to improve the efficiency of fiber

reinforcement. In steel-fiber-reinforced concrete practice, it is generally recommended that the

length of the fiber be at least twice the maximum size of the aggregate. In this study, steel fiber

lengths used were 30 mm (1.2 in.) and 50 mm (2 in.). The gradation results for the coarse

aggregate, as obtained from tests undertaken in the laboratories according to ASTM C 33, are

given in Table 3.1.

19

Table 3.1. Aggregate Gradation , Coarse Aggregates (Gravel)

Sieve Actual Percentage Cumulative CumulativeSize Weight of Weight Percentage Percentage

Retained (g) Retained Retained Passing1 in. 0 0 0 100

3/4 in. 85 9 9 911/2 in. 410 41 50 503/8 in. 160 16 66 34

#4 235 24 90 10#8 0 0 90 10

Pan 110 11 100 0

Table 3.2. Aggregate Gradation , Fine Aggregates (Sand)

Sieve Actual Percentage Cumulative CumulativeSize Weight of Weight Percentage Percentage

Retained (g) Retained Retained Passing#4 0 0 0 100#8 45 9 9 91

#16 75 15 24 76#30 70 14 38 62#50 130 26 64 36

#100 150 30 94 6#200 25 5 99 1Pan 5 1 100 0

Table 3.3. Properties of Fibers Used

Fiber Fiber Length Diameter Aspect Density SpecificName Material (mm) (mm) Ratio(l/d) (pcf) Gravity30/50 Steel 30 0.5 60 490 7.8550/50 Steel 50 0.5 100 490 7.85

PP Poly- 12.7 0.095 133.6 56.8 0.91propylene 19 Mo.,,_.,._.t 200

Note: Aspect ratio is length divided by diameter.

2O

3.3 Fine Aggregates

A graded sand, identified as type 2-NS and supplied for general concrete by Washtenaw Sand

and Gravel Company in Ann Arbor, Michigan, was used. The gradation results for the sand,

as obtained from tests undertaken in the laboratories according to ASTM C 33, are given inTable 3.2.

3.4 Mineral Admixtures

Silica fume was supplied as an emulsion by Elkem Materials Inc., Pittsburgh, Pennsylvania;

the amount of water contained in the emulsion was assumed to be 50%, as suggested by the

supplier. The amount of water contained in the emulsion and the amount of microsilica were

accounted for in computing the ratio of water to cementitious material in the mix.

3.5 Chemical Admixtures

Air-entraining agent (AEA; Vinsol resin), Darex Corrosion Inhibitor (DCI), and

superplasticizer (Melmen0 were also used. The amount of water contained in the DCI solution

(70% water) was also considered in determining the water content of the mix.

3.6 Other Admixtures

Latex emulsion, supplied by Dow Chemical, Midland, Michigan, was utilized in test series B

only. It was assumed that the latex emulsion contained 60% water, as suggested by the

supplier.

3.7 Fibers

Steel and polypropylene fibers were used in this investigation. The properties of these fibers

are summarized in Table 3.3. Information on strength and modulus of the steel fibers was

obtained from the supplier. No such information was available for the polypropylene fibers. It

should be observed that, since most fibers pull out rather than break, during the failure of fiber

21

reinforced concrete specimens, the tensile strength of the fibers is not as important as their

bond properties.

22

4

Mixture Proportions

4.1 Development Phase

Several mixes described in volumes 2 and 4 of this series of reports were tried with fibers,

particularly 1% and 2% by volume of 30/50 hooked steel fibers; however, either the fibers

could not be mixed properly or the target one day compressive strength of 5 ksi (35 MPa) was

not attained. The final HESFRC mixes selected for this investigation and described in this

chapter contain a lesser proportion of course aggregates, with smaller maximum size, than theHES mixes without fibers described in volume 4.

4.2 Production Phase

The f'mal mixes were divided in three series, A, B, and C, and a control mix. Series A

consisted of HESFRC mixes having two volume fractions (1% and 2% by volume of concrete)

and two types of fiber (hooked steel fibers having two aspect ratios and one type of

polypropylene fibers). Series B consisted of HESFRC mixes plus latex with one volume

fraction of fibers (Vf = 1%).Series C consisted of HESFRC mixes plus microsilica (silica

fume) also with one volume fraction (Vf = 1%). A flowchart showing the different series is

presented in Fig. 4.1.

The water/cement (W/C) ratio for series A was kept at 0.34. In designing the mixes of series

B, it was assumed that the latex emulsion contained 60% water, as suggested by the supplier.

Several trial mixes were tried but achieved a 1-day compressive strength less than 5 ksi.

Finally, to achieve the required 1 day strength of 5 ksi, it was decided to reduce the W/C ratio

of mix series B from 0.34 to 0.30 while maintaining the minimum desired workability of the

mix which was measured by the inverted cone test as described in Section 5.3.

23

-t_ _ R_u_

•o --1_o

N _

L -I-I °t_

.._

24

Series C, whichcontainedsilica fume, had a ratioof waterto cementitiousmaterial (i.e.,

cement plus solid microsilica)of 0.32. Since silica fume was supplied as anemulsion, theamountof watercontainedin the emulsion was assumed to be 50%, as suggested by the

supplier.The amount of water containedin the emulsion andthe amountof microsilica were

accountedforin computing the water/cementitiousratio.

The amountof water containedin the DCI solution (70% water) was also considered in

determining the watercontent of the mix.

Table 4.1 shows the mix proportions used to design mix series A, B, and C, and Fig. 4.2

describes the mix ID code used throughout this study; information on specimen ID code is

given at the beginning of each chapter for the specific type of test undertaken. In Table 4.1, all

values givenin parenthesesrepresent theratio of the weight of the component material to the

weight of cement, and the first value in each cell represents the weight of material used in

pounds per cubic yard (pcy). Table 4.2 summarizes the mix proportions in terms of ratio of

weight of component to weightof cement, and Table 4.3 gives the equivalent weight of fibersfor the various fiber volume fractions used.

Besides the adjustments made to the total W/C ratio, Table 4.1 shows two other adjustments

made to the cementcontent. The cementwas purchased from two different suppliers. Mix

series A were all designed using Type 1IIcement obtained from the first supplier.The Type 111

cement used for series B mixes was purchased from a different supplier. It was then observed

that the compressivestrengthat 1day decreased significantly.Tobalance the reduction in

strength, the cementcontent of mix series B was increased from 850 to 900 lacy.

As shown in Fig. 4.1, two of the mixes of series A, called hybrid mixes, contained either two

different fiber lengths or two differentfiber materials.It was anticipated that a hybrid mix

might have some advantages;for exmaple, one fiber might contribute to higher strength and the

other to increased toughness or ductility.

The steel fibers used in this investigationwere the Dramix 30/50 and 50/50 hooked steel fibers,

to be designated from now on as 30/50 and 50/50, respectively. The diameter of the 30/50 and

50/50 fibers is 0.5 mm, and their length is, respectively 30 mm and 50 mm, leading to aspect

ratios of 60 and 100,respectively. As shown in Fig. 4.1, two volume fractions of fibers (1%

and 2%) were investigatedfor all mixes of series A, except for the mix containing 50/50 fibers,

for which only 1% fibers by volume was used because it was not possible to properly mix 2%

50/50 fibers by volume with the desired W/C ratio.

25

A 1% $3S5

Type of Fibers Used in the Mix:

• $3 = 30/50 Hooked Steel Fibers• $5 = 50/50 Hooked Steel Fibers• P0.5 = 0.5 in. Polypropylene Fibers• P0.75 = 0.75 in. Polypropylene Fibers• $3S5 = 30/50 + 50/50 (Hybrid mix)• $3P0.5 = 30/50 Hooked Steel + 0.5 in.

Polypropylene Fibers

Fiber Volume Fraction

Mix Series A, B, or C

Fig. 4.2 - Mix ID ('ode

26

Table 4.1. Design Proportions for Mix Series A, B, and C

Mix ID Ad. C W Total S CA Mel. AEA DCI Ad.

Type (pcy) (pcy) w/c (pcy) (pcy) (pcy) (pcy) (pcy) (pcy)Control -- 850 235 0.34 1250 1550 29.75 4.25 78.5

(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A1%S3 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --

(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A2%S3 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --

(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A1%S5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --

(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)AI%P0.75 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --

(I) (0.28) (1.47) (1.82) (3.5%) ((3.5%) (9.2%)A2%P0.75 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 m

(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A1%S3S5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --

(1) (0.28) (1.47) (I .82) (3.5 %) (0.5 %) (9.2%)A2%S3S5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5

(I) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)

AI%S3P0.5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 ---(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)

A2%S3P0.5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)

B 1%S5 Latex 900 98 .30 1250 1550 31.5 2.7 90 190(1) (0.11) (1.47) (1.82) (3.5%) (0.3%) (9.2%) (0_,1)

Bl%P0.5 Latex 900 98 .30 1250 1550 31.5 2.7 90 190(1) (OdD (1.47) (1.82) (3.5%) (0.3%) (9.2%) (091)

B0%Con Latex 900 98 .30 1250 1550 31.5 2.7 90 190(1) (0.1 I) (1.47) (1.82) (3.5%) (0.3%) (9,2%) (0_,1)

C1%$5 Silica 900 198 0.32 1250 1550 31.5 2.7 90 1130

Fume (1) (0.22) (1.47) (1.82) (3.5%) (0.3%) (92%) (0.11)Cl%P0.5 Silica 900 198 0.32 1250 1550 31.5 2.7 90 1130

Fume (1) (0.22) (1.47) (1.82) (3-_%) (0.3%) (9.2%) (0.I1)C1%$3S5 Silica 900 98 0.32 1250 1550 31.5 2.7 90 1130

Fume (I) (0.22) (I.47) (1.82) (3.5%) (0.3%) (9.2%) ((3.11)

Note: Ad. = additive(latex or silica fume), C =cement, W= water,S = sand.CA =coarse aggregates,Mel. = melment.

AEA = airentrainingagent,DCI= corrosioninhibitor

Values inparanthesesareratioof weight of materialto weight of cement.

27

Table 4.2. Matrix Composition for Mix Series A, B, and C

(Proportions given by weight)

MixID [ Ad. C [Total S CA• I w olControl -- 1 0.28 0..'-t4 1.47 1.82 3.5 0.5% 9.2%

A -- 1 0.28 0.34 1.47 1.82 3.5 0.5% 9.2% --

B Latex 1 0.11 0.30 1.47 1.82 3.5 0.3% 9.2% 0.21

C Silica 1 0.22 0.32 1.47 1.82 3.5 0.3% 9.2% 0.11Fume

Note: Ad. = additive (latexor silica fume), C = cement,W = water, S = sand,CA = coarse aggregates,Mel. = melmemt.

AEA= airenlrainingagent,13(21= corrosioninhibitor

Table 4.3. Typical Fiber Content by Weight as Used in This Study

VIa Fiber Weight 2Steel 1% 132

2% 2641% 15.3

Polypropylene 2% 30.60.15% 2.3

1. Volume fractionof fibersused in thisstudy2. Poundsof fibers per cubic yard of fiber reinforcexlconcrete

28

Concerning the polypropylenefibers,twofiber lengths were uused because the supplier

discontinued the manufaculm of 0.75-in. long polypropylene fibers during the program. Thus,

mixes AI%P0.V5 and A2%P0.75 contained polypropylene fibers 0.75-in. long, while mixes

A I%S3P0.5, A2%S3P0.5, B 1%P0.5, and CI%P0.5 contained polypropylenc fibers 0.50-in.

long. Furthermore, an additional mix containing 0.15% by volume of polypropylene fibers

was prepared. This mix was investigated upon request from the SHRP advisorygroup, and

reflects mixes currently recommended by polypmpylene fiber producers for pavement

applications to control plastic shrinkage.

29

5

Mixing and Curing Procedures

5.1 Mixing Procedure

Each batch was mixed in drum mixer with a capacity of either 1 ft3 or 0.5 ft3, depending on

the number of specimens to be prepared for each series of tests. Small batches were

necessary because of the large number of different test parameters, the limited availability

of test equipment for the testing time (24 hours), and the lesser variability of fiber volume

fraction between specimens. The following steps were followed during the mixing

process. First, gravel and sand were mixed for approximately 1 minute. Then cement was

added and was mixed with the sand and gravel for another 1 minute. This was followed by

the slow addition of approximately 75% of the tap water and the superplasticizer while the

mixer was rotated back and forth about its axis to ensure an even distribution of water

within the mix. The AEA was then added, followed by DCI which was mixed with the

remaining 25% of the tap water used.

It is worth noting that the DCI was purposely added toward the end of the mixing process

because it acted as an accelerator, thus increasing the rate of concrete hardening and thereby

reducing workability.

The mixer was moved back and forth a few times, after all component materials (except the

fibers) were added, to ensure proper and uniform mixing. Finally, fibers were added to the

mix through a sieve (with 0.5-in.-square openings) to guarantee random fiber distribution

and minimize segregation and balling. Altogether, the mixing time took approximately 5 to

6 minutes.

31

After completion of the batch, the mix wa_,poured into the appropriate molds, which were

then placed on a vibrating table. The vibrating process was continued for approximately 2minutes.

5.2 Curing Procedure

Curing of all HESFRC specimens was can-ied out as follows: after placement, the

specimens were kept in their plastic molds for 24 hours, covered with a plastic sheet; the

specimens were then removed from their molds and placed in plastic bags at room

temperature until the time of testing. It was decided by SHRP project advisory group that

the ASTM-AASHTO [2] standard procedure for moist-curing would not be followed for all

HESFRC mixes. The reason for that was to simulate the actual conditions selected mixes

will be subjected to in practice, because they are expected to be used for repair of highways

and bridge decks that must be open to traffic within 24 hours. Proper moist-curing, as

recommended by ASTM-AASHTO, is not possible under such conditions.

5.3 Properties of Fresh Mix

Measurements of HESFRC fresh mix properties were obtained. These measurements

included air content, workability (by inverted slump cone), temperature, and unit weight

(Table 5.1).

Air content was measured by the pressure method (ASTM C 231 or AASHTO [3]) via a

pressure meter with a base capacity of 0.25 ft3. The device (brand name Press-Ur-Meter) is

made by Watts Company, Seattle, Washington. Vinsol resin was used as the primary AEA;

it has the advantage of reducing bleeding and leads to better concrete placing, enhanced

durability, greater freeze and thaw resistance, and enhanced resistance to wetting and

drying as well as to heating and cooling cycles. Best results are obtained when the air

content is kept between 3% to 6%; air content less than 3% gives little improvement, and

air content greater than 6% produces loss of the HESFRC compressive strength. In the

current investigation, a range of 4% to 6% air content was maintained for all mixes (Table

5.1). It was generally observed during trial mixing that a slight increase in the amount of

32

Table 5.1. HESFRC Plastic Properties

Mix ID Unit Weight Inverted Cone Temperature Air Content

(lb/ft3) Test (seconds) (OF) (%)

Control 146.6 23 69 4A1%S3 150.23 18 70 2.5A2%S3 147 25 68 3.5A1%S5 152.02 23 77 7Al%P0.75 138.88 18 70 5A2%P0.75 133.64 25 78.8 9A1%S3S5 141.6 16 75 5A2%S3S5 135.45 26 74 8Al%S3P0.5 147.13 20 79 4.5A2%S3P0.5 154.7 13 77 6.5

B 1%S5 146.1 6 77 5.75Bl%P0.5 148.5 9 79 6

C1%$5 141.8 12 75 6.75C1%P0.5 145.76 7 74 6C1%$3S5 150 7 77 7

33

AEA beyond 6% produces a significant reduction in the strength, which can bc attributed to

the increase in the volume of air voids that _c AEA produces in the mix.

The workability test was conducted by the inverted cone test rather than the slump test. The

procedure was carried out according to reco_,nendations in the report of American

Concrete Institute (ACI) Committee 544 [1] on fiber reinforced concrete as follows: the

standard metal slump cone was inverted ancLmounted on two pieces of plywood placed 3

in. above a pan placed on the ground. The mix was poured into the inverted cone and was

forced to flow out by means of a hand-held vibrator gently dropped through the mix. The

time needed for the mix to flow out of the cone was recorded (Table 5.1).

The initial temperature and unit weight of the fresh fiber reinforced concrete mixes were

also measured. The unit weight was measured according to ASTM C 138-81 [4] standard

procedures, using the 0.25-ft 3 base portion of the pressure meter. The unit weight was

taken after the sample was properly vibrated. Initial temperature was taken using a

thermomcter marked from 0 to 100OF.It was generally observed that the variation in the

temperature over the first 20 minutes was insignificant (less than lop) in all mixes.

Table 5.1 summarizes the fresh properties of all mixes used in this investigation. A

correlation was observed between the amount of air in the mix and the unit weight: the

higher the air content, the lower the plastic unit weight.

The addition of 1% to 2% by volume of polvpropylene fibers caused a noticeable reduction

in the unit weight of the mix, thus leading to a substantial reduction in the compressive

strength. This was observed particularly in mixes Al%P0.75 and A2%P0.75, shown in

Table 5.1, in which long fibers were used. However, mixes B1%P0.5 and C1%P0.5,

containing 1% by volume of 0.5-in.-long polypropylene fibers, showed little or no

reduction in the unit weight. This finding was attributed to the smaller volume fraction of

shorter fibers and to the fact that latex and microsilica, which were mostly used with the

mixes containing 0.5-in.-long fibers, act as dense fillers and improve the workability of themix.

The plastic unit weight of mix A2%S3S5 (i.e., the hybrid mix containing 1% each by

volume of 30/50 and 50/50 hooked steel fibers; Table 4.1 and Fig. 4.2) was observed to be

low relative to the A series mixes because of the relatively high air content (8%). This high

air content and low plastic unit weight were attributed to the large volume of voids present

in the mix, believed to be caused primarily by the presence of 1% by volume of 50/50

hooked steel fibers, which are 2 in. long.

34

5.4 References

i. ACI Committee 544. Measurement of Properties of Fiber Reinforced Concrete. ACI

Material Journal, 85, no. 6, (November/December 1988): 583-593.

2. ASTM Standards. Standard Practice for Mala'ng and Curing Concrete Test Specimens

in the Laboratory. ASTM C 192-90a, vol. 04.02.

3. ASTM Standards. Standard Test Method for Air Content of Freshly Mixed Concrete

by the Pressure Method. ASTM C 231-91, vol. 04.02.

4. ASTM Standards. Standard Test Method for Unit Weight, Yield, and Air Content

(Gravimetric) of Concrete. ASTM C 138-81, vol. 04.02.

35

6

Compression Tests

6.1 Experimental Program

The compression tests were subdivided into three major groups: (1) series A, consisting of

HESFRC mixes having two values of fiber volume fractions (1% and 2% by volume of

concrete), two types of fibers (hooked steel and polypropylene), and for the hooked fibers,

two lengths (30 and 50 mm); (2) series B, consisting of HESFRC mixes containing 1%

fibers by volume and 10% latex solids by weight of cement; and (3) series C, consisting of

HESFRC mixes containing 1% fibers by volume plus 10% microsilica (silica fume) by

weight of cement. A flowchart of the testing program is shown in Fig. 6.1.

For each mix, standard cylindrical specimens were prepared for testing at 1, 3, 7, and 28

days. At least three specimens were tested for each parameter. Since the normal cylinder

size used in this investigation was 4 x 8 in., 6 x 12-in. cylinders were also prepared and

tested at 1 day to provide some correlation between the two sizes. Table 6.1 shows the

number and size of specimens tested for each mix and the type of test performed.

Specimen ID notation is explained in Fig. 6.2.

6.2 Test Apparatus and Procedure

Each time series (time of 1, 3, 7 and 28 days) was subjectedto two types of tests: (1) a

nondestructive test to measure the static modulus of elasticity (Ec) and (2) a destructive test

consisting of the complete stress-strain curve.

37

Table 6.1. Number of Specimens Tested

Mix Series tFiber Fiber Numberof CylindersTestedType Type Volume 4 x 8 in. 6 x12 in.

Fraction Cr- E + Ee o - E

Vf (%) Test Conducted at (days)1 3 7 28 1

HES A Control 0 3 3 3 3 2

HES A 30/50 1 3 3 3 3 2HES A 30/50 2 3 3 3 3 2HES A 50/50 I 3 3 3 3 2HES A PP 1 3 3 3 3 2

HES A PP 2 3 3 3 3 2HES A 30/50 + PP 1 3 3 3 3 2HES A 30/50 + PP 2 3 3 3 3 2lIES A 30/50 + 50/50 1 3 3 3 3 2HES A 30/50 + 50/50 2 3 3 3 3 2

HES + LA B 50/50 I 3 3 3 3 2HES + LA B PP 1 3 3 3 3 2HES + LA B Control 0 3 3 3 3

lIES + SF C 50/50 1 3 3 3 3 2

lIES + SF C PP 1 3 3 3 3 2

HES + SF C 30/50 + 50/50 1 3 3 3 3 2

Notes:LA= latex;PP= polypropylene;SF= silicafume;o - e = stressstraincurveF-.e= elasticmodulus.

38

+e.._ .

E

l-l- ,,e l N

o

g_

" _ _'_ ,,

E m_

0 _'_ _"

g _

I gtg_ NIl

- 71,_!° I_ "

39

1D 48 fc 1

- Specimen Number (1, 2, or 3)

- A = Average of all specimens

- S = Standard deviation

- fc = Compressive and elastic modulus

- fr = Flexural

- ft = Splitting tensile

Size of Cylinder

48 =4 x8in.

¢_12= 6x 12 in.

_[ime of Testing,

. ID = 1 day

- 3D = 3 days

- 7D = 7 days

- 28D = 28 days

Fig. 6.2 - Specimen ID Code.

40

Figs. 6.3 and 6.4 show the setups used for the elastic modulus and complete stress-strain

curve tests, respectively. In each case, the load was measured by a load ceil, while the

deformation was measured using three linear voltage differential transducers (LVDTs)

placed at 120° intervals around the specimen. The stress-strain curve in compression was

obtained for all cylinders tested. The curve provided information on the strength and

ductility. The three curves obtained from the three identical cylinders of each series were

averaged to obtain the average stress-strain curve for the series. Average curves for

different series were compared to clarify the influence of time, specimen size, and various

parameters such as fiber content, fiber type, and the addition of either rnicrosilica or latex.

All measurements were recorded via a data acquisition system, using voltage signals from

the LVDTs and the load cell of the testing machine.

The elastic modulus test was performed on 4 x 8-in. specimens only. The fixture used for

this type of test (Fig. 6.3) consisted of two aluminum rings separated by temporary bracing

that held the top and bottom rings apart at exactly 4-in. gauge length. The bracing was

removed after the two rings were fixed to the concrete cylinder, to aUow for free movement

of the tings. The movement between the two rings was measured by three LVDTs placed at

1200 intervals around the cylinder. A 600-kips capacity Instron universal testing machine

equipped with a swivel head platen was used for all tests. Each specimen was loaded by the

strain-controlled method at a rate of 0.0005 in./sec, and the load was increased up to 50%

of the anticipated strength, which was assumed to be equal to the strength of the control

specimen. Before testing, each specimen was loaded and reloaded twice up to 10% of ]'c

to take care of all loose joints and reduce as much aspossible the curvilinear response that

would otherwise distort the initial portion of the curve. The fixture used to determine the

modulus of elasticity was used up to maximum or peak load. The fucture was removed

beyond the peak load to avoid damage. Thus, the strain recorded thereafter represented the

strain obtained from the platen displacement, as is described next.

Once the elastic modulus test was completed, the rings were removed and the cylinder was

tested up to failure (Fig. 6.4). Here, three LVDTs placed at 120° intervals between the

platens of the testing machine were used to record the deformation of the specimen. The

imposed displacement was carded out until the resistance on the descending branch of the

load deformation curve was less than 10% of the peak stress.

The collected data were reduced and averaged, and various plots were obtained for each

specimen and for the average of each series. The procedure followed for data reduction and

averaging is explained next.

41

Fig. 6.3 - Test Set-up for Measurement of Elastic Modulus

42

Fig. 6.4 - Test Set-up Used to Determine the Stress-Strain Response in Compression

43

Table 6.2. Summary of the Average Values of f'c and Ec Obtained for EachTime Series

Mix ID Specimen ID Elastic Modulus Compressive

(ksi) Stren[th (ksi)

Control IIM8fcA 4,129.61 5.08

Control 1D612fcA --- 4.485

Control 3D48fcA 4r155.04 6.55

Control 7D48fcA 4T038.84 6.92

Control 28D48fcA 3,793.71 7.00

A 1%S3 1D48fcA 4,408.78 5.97

A1%S3 1D612fcA .... 5.575

A1%S3 3IM8fcA 3_975.16 6.66

A 1%S3 7D48 fcA 4r644.38 7.54

A 1%S3 281348fcA 4,777.67 7.67I

A2%S3 1D48fcA 3,843.79 6.07

A2%S3 1D612fcA --- 4.65

A2%S3 3IM8fcA 4,093.25 6.71

A2%S3 7IM8feA 4r364.66 7.55

A2%S3 28IMSfcA 6r402.53 7.60

A1%S5 1D48fcA 2r698.22 5.05

A1%S5 ID612fcA -- 5.6

A1%S5 3D48fcA 3,496.97 5.72

A1%S5 7D48fcA 3,522.72 5.98

A1%S5 28D48fcA 3,678.96 6.30

A 1%P0.75 1D48fcA 2r926.07 4.15

Al%P0.75 1D612fcA -- 4.525

Al%P0.75 3IM8fcA 3,121.67 4.95

A 1%P0.75 7IMSfcA 3,247.98 5.83

A 1%P0.75 28D48fcA 2,970.69 5.56

continued on next page

44

Table 6.2. Summary of the Average Values of f'c and Ec Obtained forEach Time Series; continued


(ksi) Strength (ksi)

A2%P0.75 1D48fcA 2,785.07 3.07

A2%P0.75 1D612fcA -- 2.6

A2%P0.75 3D48feA 2,996.18 4.36

A2%P0.75 7D48fcA 2,676.45 4.58

A2%P0.75 28D48fcA 2,653.86 4.77

A1%S3S5 11M8fcA 2,922.02 5.51

A1%S3S5 ID612fcA --- 4.085

A1%S3S5 3IM8fcA 3r830.36 6.26

A1%S3S5 7D48fcA 3T566.36 6.93

A1%S3S5 28IM8fcA 3,943.39 7.88

A2%S3S5 IIM8fcA 2,548.26 3.20

A2%S3S5 ID612fcA --- 5.065

A2%S3S5 3IM8fcA 2,818.70 3.38

A2%S3S5 7D48fcA 3,402.38 5.34

A2%S3S5 28D48fcA 3,457.09 6.91

A1%S3P0.5 1D48fcA 2r485.30 3.38

Al%S3P0.5 1D612fcA --- 3.65

A1%S3P0.5 3IM8fcA 2,860.27 3.87

Al%S3P0.5 7D48fcA 3;045.06 4.47

AI%S3P0.5 28IM8fcA 2,706.07 4.90

A2%S3P0.5 1D48fcA 1,515.02 4.70

A2%S3P0.5 1D612fcA -- 3.675

A2%S3P0.5 3IM8fcA 3,529.95 5.17

A2%S3P0.5 7D48fcA 2,992.13 5.50

A2%S3P0.5 28IM8fcA 3,438.7 6.04


45

Table 6.2. Summary of the Average Values of f'c and Ec Obtained forEach Time Series; continued



B0%Con llMSfcA 2.272.3 4.34

B0%Con 3IM8fcA 3r756.00 6.25

B0%Con 7IMSfcA 3,840.00 6.17

B0%Con 28D48fcA 3,510.00 8.13

B 1%S5 11M8fcA 3,143.51 4.50

B 1%S5 1D612fcA -- 3.19

B 1%S5 3IMSfcA 4,161.98 5.75

B 1%S5 7D48fcA 3r458.95 5.17

B1%S5 28IM8fcA 7r495.01 6.45

B1%P0.5 11M8fcA 2,265.77 2.93

B1%P0.5 1D612fcA -- 3.05

B 1%P0.5 3D48fcA 2,794.65 4.31

B 1%P0.5 7D48 fcA 2,857.79 4.47

B 1%P0.5 28IM8fcA 61600.03 5.79

C 1%S5 1D48fcA 2r476.80 5A6

C1%$5 1D612fcA -- 5.415

C1%S5 3IM8fcA 1r972.88 5.90

C1%$5 7IM8feA 3r658.34 7.55

C1%S5 28IM8fcA 4,094.45 8.40

Cl%P0.5 1D48fcA 2,813.06 3.45

C1%P0.5 113612fcA -- 3.9

C1%P0.5 3IM8fcA 3_636.84 4.81

C 1%P0.5 7IMSfeA 3r387.24 5.58

C1%P0.5 28IM8fcA 2,923.68 5.89

C1%S3S5 1D48feA 3,283.33 4.78

C1%$3S5 1D612fcA -- 4.675

C 1%S3S5 3D48feA 4,254.05 5.49

C 1%S3S5 7IM8fcA 3r447.03 7.34

C1%$3S5 28IM8fcA 3,204.25 7.40

46

6.3 Data Analysis and Test Results

Table 6.2 summarizes the average values of the compressive strength, fc, and elastic

modulus for each mix tested at 1, 3, 7, and 28 days. Note that the average values of fc

represent the average of three 4 x 8-in. and two 6 x 12-in. cylinders. Details on the values

of fc and Ec for each individual specimen, as well as the average and standard deviation

for each time series, can be found in Appendix A (Tables A.1 to A.16).

The data collected from the load ceil and the LVDTs were reduced and averaged by means

of computer programs written in FORTRAN and BASIC. Therefore, the reduced data

recorded consisted of (1) the load in kips and (2) the displacement in inches. Several

programs were used to arrive at the final plots shown in following sections. These

programs were either developed specifically for this project or obtained from different

sources [i, 5, and 6]. The methods and assumptions used in arriving at the final plots for

both the modulus of elasticity and the entire stress-strain curves are explained next.

For the modulus of elasticity, a computer program written in BASIC [6] was used to

reduce the recorded data from kips and inches to stress units (kips per square inch) and

strain units (i.e., in./in.). The program initially starts by reading each set of data points

consisting of the load and the corresponding displacement. If the encountered value of the

load is negative, the program skips this set until it encounters the first positive load in the

file. The physical interpretation of the change of the load sign from negative to positive is

that the point of contact between the swivel head attached to the load cell and the cylinder

has been attained. This point is set as the origin on the stress-strain curve. Therefore, the

absolute stress versus absolute strain values can now be computed as follows:

Pi-eo07 = A

di- do

Ei = LGL

where

cri = Absolute compressive stress corresponding to the ith set of data

Po = Initial compressive load

47

Pi = Compressive load measured relative to Po

A = Cross-sectional area of the 4 x :g-in.cylinder (12.57 in2)

Ei = Absolute initial strain corresponding to tri

do = Initial displacement corresponding to load Po

di = Displacement corresponding to load Pi

LGL = Gauge length (4 in.)

It was observed that the initial portion of the stress-strain curve was curvilinear over a small

stress range. To account for this effect in the computation of the secant modulus of

elasticity Ec, the methodology described in ASTM C 469, AASHTO, and ACI was

followed [1, 2, and 6]. The secant modulus was taken as the slope of the line joining the

maximum point (of coordinates Pi and di, here taken equal to 50% of anticipated

compressive strength) and a point corresponding to a strain of 50 microstrain (coordinates

Po and do).

The average Ec value for each time series was calculated from the Ec values obtained from

each specimen.

Three programs were used to convert the data obtained from the data acquisition system to

the final form, the entire stress-strain curves shown in the following sections. The

procedures used for data reduction and averaging were automated by means of a central

batch file to achieve efficiency and minimize the possibility of error.

The purpose of the In'st program was to reduce the relative load versus relative

displacement data sets to absolute values of stresses and corresponding strains (i.e.,

relative to the origin) in a manner similar to the procedure explained earlier for the modulus

of elasticity. The absolute stress and absolute strain values for each specimen were stored

in separate f'des, then used as input data fries to calculate the average stress versus average

strain coordinates for each test series [7]. Individual stress-strain curves for each specimen

and average curves for the specimens of the same series were then plotted.

A special averaging technique was followed to produce the average curve for each time

series. First, the average peak stress and the corresponding strain at peak stress were

obtained by averaging the peak stresses recorded for the individual test specimens and theircorresponding strain values.

The averaging process for the remaining data was carried out as follows. First, the peak

point was determined for each specimen. It was found that using 50 points to describe the

48

ascending branch provided a suitably smooth curve. Therefore, the stresses on the

ascending branch of each stress-strain curve were taken at 50 equal strain intervals. In

general, the value of this interval was different for each specimen, since each had a slightly

different strain at the peak. The average stress value at each interval was then calculated,

and this value was taken as the stress of the average curve at the corresponding strain

interval, based on the peak point of the average curve. The same approach was used to

calculate the coordinates of the average stress-strain curve along the descending branch.

Finally, the stress-strain curves were systematically plotted for (1) each specimen of the

same series and the series average; (2) the average curves comparing each time series, that

is, 1, 3, 7, and 28 days (Appendix A, Figs. A. 1 to A.79); and (3) the average curves at 1

day comparing the 4 x 8-in. and 6 x 12-in. cylinders. Additional figures were also

produced to compare average maximum strengths and elastic moduli observed for each

series at various times.

6.3.1 Stress versus Strain Response with Time

This section focuses on the effect of time on the stress-strain response of all HESFRC

mixes [5]. The effect of microsilica and latex on the stress-strain relationship with time is

also examined and compared with previous studies [3, 4, and 8]. Selected average graphs

of the stress versus strain response with time as well as the stress versus strain response

for different cylinder sizes (at 1 day) are shown this section.

In general, the requirement for achieving a compressive strength of 5 ksi or greater at 1 day

was met for almost all mixes except those containing polypropylene fibers.

Fig. 6.5 shows the stress-strain curves of the control mix tested at 1, 3, 7, and 28 days.

The effect of specimen size at 1 day is illustrated in Fig. 6.6. It can be observed that (I) the

compressive strength increases from about 5 ksi at one day, to about 6.5 ksi at 3 days, to 7

ksi at 7 days and remains at about 7 ksi at 28 days; (2) little ductility can be counted on

following the peak load; and (3) the strength of the 6 x 12-in. cylinders is, as expected,

slightly lower (here about 11% ) than that obtained from the 4 x 8-in. cylinders.

Fig. 6.7 shows the effect of adding 1% by volume of 30/50 hooked steel fibers. It is

observed that although 3"c slightly increased in comparison with the control mix (17%),

the area under the curve is much larger, thus indicating a substantial increase in ductility

and energy absorption to failure. The figure also shows that the slope of the descending

49

o_|L FRC - Tes'_ at 1,3,7, and 28 days

o__ Control HIx

r_ _ Cylinder size. 4' x 8'

v .................."'"Fll! --- 7days

,00 .0! .02 .03 .04 .05 .06

STRAIN

Fig. 6.5 - Stress vs. Strain Response of Control Mix with Time

o_m

FRC - Test at I dayK- Control HIx

m

- Cylinder slze_ 4' x B° ¢_nd6" x 12'_,

Ul u_ 4' x 8'A

fu_ , ,,

Ldn'¢4 II--q3

_d

1_" I I I I I I I I I I.00 .Or .02 .03 .04 .05 .06

STRAIN

Fig. 6.6 - Effect of Cylinder Size on the Stress-Strain Response of the Control Mix

5O

FRC - Test at 1,3,7,and 28 dagsO3

30/50 Hooked Flbers, t/d=60

_/_ = I% ( o? Concrete)rN_ ° °

Cgilnder slze,4' x 8'

1 d_ W

................3 dags

V_ 7 dQgs

_ 28 dags

I 1 I 1 I I 1 1 I,00 .01 .02 .03 .04 ,05 ,06

STRAIM

Fig. 6.7 - Stress vs. Strain Response of Mix A1%S3 with Time

i l FRC - Test at I da,j

30/50 Hooked Fibers,t/d=60

Vf = 17.( oF Concrete)

Cgtinderslze,4" x 8' and 6' x 12'

_ 4' × 8'V

, 6' x 12'_ .,=.: ',

I--rY_ "-.

o _'T"|w

I I I I I I I 1 I I 1.00 .01 .Oe .03 .04 .05 .06

STRAIM

Fig. 6.8 - Effect of Cylinder Size on the Stress-Strain Response of Mix AI %S3

51

branch slightly decreases with an increase in the compressive strength. The increase in fc

for the series tested at 3, 7, and 28 days was 11.6%, 26.3%, and 28.5%, respectively, in

comparison with the series tested at 1 day Fig. 6.8 compares the compressive strength

obtained from 4 x 8-in. and 6 x 12-in. cylinders tested at 1 day. Generally, the 4 x 8-in.

cylinders lead to a slightly higher compressive strength than the 6 x 12-in. cylinders.

Fig. 6.9 shows the test results obtained from testing the mixes containing 2% by volume

of concrete of 30/50 hooked steel fibers. "Ihe trend observed in this figure follows that

observed in Fi_. 6.7; that is, the slope of the descending portion of the 28-day curve

increases when compared with the 1-, 3-: and 7-day curves, indicating a loss of ductility

beyond the 7-day life. It is not clear whether this is simply due to normal variability in the

results, or whether age leads to additional brittleness. Fig. 6.10 compares the stress-strain

curves obtained from 4 x 8-in. and 6 x 12-in. cylinders tested at 1 day. Unlike the mix

containing 1% by volume of 30/50 fibers, the mix containing 2% of 30/50 fibers showed a

substantial decrease in compressive strength (25% decrease). This result could not be

explained but is reported as observed.

The stress-strain curves of the mix containing 50/50 hooked steel fibers are plotted in Fig.

6.11. Contrary to the observations made on Figs. 6.7 and 6.9, the slope of the descending

portion for all time series does not show any significant increase with time, indicating that

the loss of ductility with time is insignificant. Fig. 6.12 shows a comparison between the

curves obtained from the 4 x 8-in. and 6 x 12-in. cylinders tested at 1 day. Here, the

compressive strength of the 6 x 12-in. cylinder is approximately 11% higher than the

strength of the 4 x 8-in. cylinder.

Fig. 6.13 describes the mix containing 1% by volume of polypropylene fibers. The figure

clearly shows two major drawbacks in using polypropylene fibers. The first is the

significant drop in fc (-20%) at 1 day relative to the control mix. The reason for this sharp

drop is not very clear and may be attributed to the low elastic modulus of the polypropylene

fibers and their poor bonding properties in comparison with steel fibers.

The second drawback can be explained by observing the descending branches of the 7- and

28- day curves. Unlike the 30/50 steel fiber mix at 1% and 2% volume fraction, the

polypropylene mix at 1% volume fraction shows a significantly lower ductility. This lower

ductility may also be explained by the lower elastic modulus and poorer bond properties of

polypropylene fibers. A comparison of the stress-strain curves for the 4 x 8-in. and 6 x 12-

in. cylinders is illustrated in Fig. 6.14.

52

o4 L_ __ FRC - Test =t 1,3,7, =nd 28 d=yso_ 30/50 Hooked Fibers, L/d=60

,'jl_ll..i,% VF = 27. ( oF Concrete)

iL,\ =,..,,.x..L -]/ \'t",, '..............._<'o_=

,_ °%, •

,,,-,l

,00 .01 ,02 ,03 ,04 .05 ,06

STRAIN


m l-i- FRC - Test =t I dayr_ 30/50 Hooked Flbers, I/d=60

- i- VF = 2?. ( oF Concre'ce)_0- _ CyLinder size/ 4' x 8' _nd 6' x 12'

/ \_ -U1

_-/.. \ , _.x.,v - I"", \ . 6' x 12'(/) _-C/)i.d -n" ei -

_ -

"iI I I I I I I l I l I,00 .01 .02 .03 ,04 .05 ,06

STRAIN

Fig. 6.10 - Effect of Cylinder Size on the Stress-Strain Response of Mix A2%S3

53

i l FRC - Test at 1,3,7,and 28 dczys

50/150Hooked Fibers, t/d=lO0

V,_ = I_.(of Concrete)

Cy|Inder size.4' x 8'

° A_ I day

V) tn I_ _._ _ --- - 7 daysO_ _ 28 doysLLI_rV :.

V_ r_

Od

- .................I I I I I I I I I I I ,

.00 .01 .oe .03 .04 .05 .06

STRAIN


QdI

FRC - Test at I day

r_- 50/50 Hooked Fibers, t/d=10O

- VF' = I_.(of Concrete)

- Cylinder slze,4' x 8' and 6' x 12'

__ - {'\

_ '._ \ 4' x 8'Y' f

v ___ 6' x 12"

LLJ $t

' ,.,,__°

I I I I I I I I I I I.00 .01 .Oe .03 .04 .05 .06

STRAIN

Fig. 6.12 - Effect of Cylinder Size on the Stress-Strain Response of Mix AI %S5

54

°dLL FRC - Test at 1,3,7, nnd 28 daysN| 3/4' Potgpropyiene Fibers

.I VF = IZ (oF Concrete)!-- Ctjtlnder size, 4' x 8'

"_ L i_ --1 do,y'

_ °%°°°°°°°.........

.00 .01 .02 .03 .04 ,05 ,06

STRAIN

Fig.6.13 - Stress vs. Strain Response of Mix AI %P0.75 with Time

odB

FRC - Test at I day

r_- 3/4' Poigpropylene Fibers- VF = I% (oF Concrete)

_- Cylinder size, 4' x 8' and 6' x 12'

"U_y_, 4'x8'V

;; 6' x 12'

ni

1 I I I I 1 I,00 .01 ,02 .03 .04 .05 .06

STRAIN

Fig.6.14. Effectof CylinderSizeonthe Stress.StrainResponseof Mix AI %P0.75

55

Fig. 6.15 shows the same type of polypropylene fibers used at a volume fraction equal to

2% by weight of concrete. Here, the reduction in the compressive strength at 1 day is

approximately 40% of the control mix and almost double the decrease observed for the mix

containing 1% by volume of polypropylene fibers. Fig. 6.16 shows a comparison between

the 4 x 8-in. and 6 x 12-in. cylinders. The figure clearly shows that the compressive

strength of the 4 x 8-in. cylinder is slightly higher than that for the 6 x 12-in. one.

Fig. 6.17 illust'ates the results for the hybrid mix containing 30/50 + 50/50 hooked steel

fibers at a total of 1% by volume. A hybrid_mix is defined as a mix that (1) contains more

than one type of fiber or (2) contains the same type of fibers with varying aspect ratios.

Several conclusions can be arrived at from Fig. 6.17: (1) the strength at 3, 7, and 28 days

increases 14%, 25%, and 43%, respectively, when compared with the i-day strength; (2)

the slope of the descending branch decreases with an increase in strength. In Fig. 6.18, the

stress-strain curves obtained from 4 x 8-in and 6 x 12-in. cylinders tested at 1 day are

compared. The trend observed here confmns the trend observed with other mixes.

Fig. 6.19 describes the curves for the same: mix as for Fig. 6.18, except that the volume

fraction of fibers is doubled (2%). A 37% decrease is observed in the compressive strength

at 1 day relative to the plain matrix. However, the strength picks up at a later age and good

ductility is observed. Fig. 6.20 shows the stress-strain curves obtained from 4 x 8-in. and

6 x 12-in. cylinders tested at 1 day.

Similar graphs were plotted and analyzed for all the other test series. They are included in

Appendix A, Figs. A.80 to A.94. However, conclusions drawn from the test results are

summarized in section 6.4.

6.3.2 Stress versus Strain Response." Comparison between Series

The purpose of this section is to compare the stress-strain relationships of series A, B, and

C mixes tested at 1 and 28 days. It should be noted that specific comparisons of the

compressive strength values are discussed in section 6.3.3.

Fig. 6.21 compares mix series A tested at 1 day, each mix having a different type of fiber at

a volume fraction of 1%. The figure clearly shows that the mix containing the 30/50 fibers

leads to the highest compressive strength and the largest area under the stress-strain curve,

and the mix containing polypropylene fiber's lead the lowest compressive strength and

ductility.

56

05

FRC - Test cLt1.3.7,omd 28 do_s

r_- 3/4' PoLypropgteneFibersVF = 27.( oF'Concrete)

,._- Cytmnderslze,4' x 8'

_.__-i dory

,:., ...............3 d=_s

,00 .01 ,02 .03 .04 ,05 .06

STRAIN

Fig. 6.15 - Stress vs. Strain Response of Mix A2%P0.75 with Time

05m

FRC m Test (_tI dcLy3/4' PotypropyteneFlbers

- Vf" = 2% (oF Concrete)

- Cytlnderslze,4' x 8' ond 6' x 12"om

Ul u-)- 4' x 8'i"-" - 6' x 12'

C_bJ -rv_

ai

P

I I I I I I I I I I I.00 ,01 ,02 ,03 .04 ,05 36

STRAIN

Fig.6.16. Effectof CylinderSizeon the Stress-StrainResponseof MixA2%P0.75

57

FRC - Tes¢ =t 1,3,7, and 28 days

r_i Hybr'ld HIx30/50 + 50/50 Hooked Fiber's

VF := lY. ( oF ConcreCe)

_1 U_ Cytlnder" size, 4' x 8'I_" __1 day

(/) _: ,, 3 days(/)I.d - - -7 daysn/c_I-- • _28 days(/1

o

I I I I 1 I I I I,00 ,01 .0;' .03 .04 ,05 .06

STRAIN

Fig. 6.17 - Stress vs. Strain Response of Mix A1%S3S5 with Time

c_

t FRC - Test _t 1 d=u.,

r_ Hgbrld HIx30/50 + 50/50 Hooked Fibers

o

_o VF = IZ ( o£ Concre_ce)

_L' _ Cylinder" size, 4" x 8' and 6' x 12'

v I- / _ ___4'xe'

(_ ,¢: -6' x 12'

,00 .01 .02 ,03 ,04 .05 .06

STRAIH

Fig. 6.18. Effect of Cylinder Size on the Stress-Strain Response of Mix AI %S3S5

58

FRC - Test Qt 1,3,7,and 28 days

HgbrldHlx30/50 + 50/50 Hooked Fibers

_ VF = 2% (oF Concrete)

_ CyLinder slze, 4' x 8'

v I day

V3 _ _ ",, ...............3 daysbJ ",. _ - -7 dags

rv m ", 28 days

:" "'"'"_C'.-....

i i

I l ! I.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. 6.19 - Stress vs. Strain Response of Mix A2%S3S5 with Time

o_

FRC - Test at I day

HybridHIx30/50 + 50/50 Hooked Flbers

VF = E_.(oF Concrete)/-%

," ',, C_tlnder" size, 4' x 8' _nd 6' x 12',,, u'i -.v 4' x 8'

_: ' "- 6' x I:_'_ 4,,

n," ei -.

-o

.00 .01 .0;_ .03 .04 .05 .06

STRAIN

Fig. 6.20 - Effect of Cylinder Size on the Stress-Strain Response of Mix A2%S3S5

59

- FRC - Test ot I da_

/ Ct)mp_ro_lve EvoLu_lonot" DIFFerent Mixes

_ ,_: .:: .,.: V_' = t_ . ,_X_ r- i,', CL.+tmdersize, x

4 8

_' , ': ...... 30/50 Hooked Steel'_. -/

m:1- _/_ _, "': - - - 50/50 Hooked St;eeL

| • . •

dE+\ ",.+

.-J L _.,..

.00 .01 .02 03 .04 .05 ,06

STRAIN

Fig. 6.21 - Effect of Fiber Type on the 1 Day Stress-Strain Response (Vf=I%)

°

;'e. FRC - Tes+ ot 28 doLJs

Conporotlve [votuotlon

. :,. : of DIFFerent Hlxes,,o :' ' : V f = IZBt %

:!I- tlt \ ... 30,/50Hooked$'teet!-!l \ "" - - - .o,/5oHookeds,,,,i- :1 _,"', _ z,/a"eo,_prop_,ene

_i-+1 \::',_,'I "(,'..."',.

I-:1 "_:.. "'-C -.%, b

.00 .01 .02 ,03 ,04 .05 .06

STRAIH

Fig. 6.22 - Effect of Fiber Type on the 28 Day Stress-Strain Response (Vf=l%)

6O

Fig. 6.22 compares the same three mixes tested at 28 days. The figure shows that the 30/50

mix has the highest compressive strength but undergoes a sharp drop in the post peak

response. In contrast, the 50/50 mix shows a milder post peak slope. It may be concluded

that the response of the 50/50 mix at 28 days is better than that of the 30/50 mix. The

response of the polypropylene mix relative to the other mixes was poorer, in terms of both

strength and ductility.

Fig. 6.23 shows the mixes of series A at 1% volume fraction of fibers tested at 28 days. It

can be observed that both the 30/50 and 30/50 + 50/50 mixes gave the highest compressive

strength and behaved very similarly. However, they showed a sharper slope increase in the

post peak response as compared with the 50/50 mix, which in turn showed a slightly lower

compressive strength. The 30/50 + polypropylene mix gave the lowest compressive

strength and the smallest area under the stress-strain curve.

Fig. 6.24 compares three mixes of series A containing 2% fibers and tested at 28 days. The

30/50 mix gave the best overall response. The performance of the 30/50 + 50/50 mix was

similar to that of the 30/50 mix, except that the compressive strength was slightly lower.

The response of the 30/50 + polypropylene mix was acceptable, but with noticeably lower

compressive strength in comparison with the two other mixes.

Similar graphs were plotted and analyzed for all the other parameters studied. They are

included in Appendix A, Figs. A.95 to A. 104. However, conclusions drawn from the test

results are summarized in section 6.4.

6.3.3 Compressive Strength

The purpose of this section is to compare the compressive strength of various mixes,

observe its variation with time, and draw relevant conclusions. Typical curves are

described next. However, the graphs developed for all parameters are included in Appendix

A, Figs. A.105 to A.111.

Fig. 6.25 shows the variation of .fc with time for mix series A containing 1% by volume

of fibers. Mixes 30/50 and 50/50 and hybrid mix 30/50 + 50/50 gave the required

minimum compressive strength of 5 ksi at 1 day. The other two mixes, containing

polypropylene and polypropylene + 30/50 hooked steel fibers lead, respectively, to 20%

and 33% reductions in fc at 1 day compared with the control mix.

61

o_

FRC - Tes_ ,,t: 28 d=ysl_ Conpar_clve EvGlu_lon

oF !OIFFeren_cHlxesVF = I;':

L/1u'J Cy|l.der slze_ 4" x 8'v ___ 30/50 Hooked S'tee(

(/) _: ......... 50/50 Hooked Steel

L,J ... - - -30/50 + 50/50 Hooked S_.eetry_ ...I-- 30/50 Hooked Steel Fibers(,_ '%.. ----

'.%. + 1/2' Potypropgtene

"..•...

.,,..

""-.,,..., .....

.00 .01 .02 .03 ,04 .05 .06

STRAIN

Fig. 6.23 - Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=1%)

I_ FRC - Test at 28 daysComporatlve Evatu='l:lonof OIfFerent Mixes

__ _ Ct,jIJndersize1 4' x 8"V

30/50 Hooked Steer

(/) _ - "- -30/50 + 50/50 Hooked Steer(/)I,I : 30/50 Hooked S'ceei Fibers

I-- + I/P' Pol_Jpropgtene(/)

o.i

°

,00 .01 .02 ,03 .04 .05 .06

STRAIN

Fig. 6.24. Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=2%)

62

The mix containing 30/50 hooked steel fibers showed an average increase in fc of

approximately 10% over the control mix at all time intervals. Next in performance was the

hybrid mix, 30/50 + 50/50, which led to a 10% average reduction in strength compared

with the 30/50 mix. As expected, the 50/50 mix showed an increase in fc over time.

However, that increase was less than the increase observed with the control mix. The

strength reduction observed in the 50/50 mix is believed to be due to the large volume of air

entrapped during mixing of the fibers. This explanation is supported by the air void tests

conducted on all three mixes and shown in Table 5.1, in which air contents of 3.5%, 5%,

and 7% were obtained for the 30/50, 30/50 + 50/50, and 50/50 mixes, respectively.

Fig. 6.26 also shows a reduction in strength when polypropylene fibers are used.

Fig. 6.26 describes the results of the same mixes discussed in Fig. 6.25, except that the

volume fraction of fibers has changed from 1% to 2%. The figure shows that the 30/50 mix

still leads to an overall increase in fc over the control mix. The 30/50 and the

polypropylene + 30/50 mixes gave the required minimum 5 ksi compressive strength,

whereas other mixes did not meet this criterion. The 30/50 and polypropylene + 30/50

mixes gave a 20% increase and a 7% reduction in fc at 1 day compared with the control

mix, whereas the 30/50 + 50/50 and polypropylene mixes gave a 33% reduction in fc at 1

day compared with the control mix. The presence of at least 1% by volume of 30/50 fibers

in the polypropylene + 30/50 mix enhanced the overall behavior, even in the presence of

1% polypropylene fibers. The 30/50 + 50/50 hybrid mix did not give satisfactory results

because of large air voids (8%), as shown in Table 5.1. Fig. 6.26 shows that the 28-day

strength of the 30/50 + 50/50 hybrid mix was approximately equal to that of the control

mix. The polypropylene mix gave the lowest strength, with an average 30% reduction

compared with the control mix at all time intervals. It is believed that this was primarily due

to the high volume of air entrapped in the mix (9% air content).

Fig. 6.27 provides a comparative evaluation of the effect of latex and silica fume on fc for

the mix containing 1% by volume of 50/50 fibers. The figure shows that latex reduces the

strength from that of the plain fiber reinforced concrete (FRC) mix by approximately 11%

at 1 and 7 days. At 28 days, the strength of the latex-modified mix approaches that of the

plain mix. The compressive strength of the silica-fume-modified mix at 1 and 3 days does

not change significantly. However, at 7 and 28 days, the compressive strength increases by

7% and 6%, respectively, over the plain FRC mix.

63

8

7 mr

_ 4 ..............._. 1%

3 ..... "'" Control30/50

2 ---¢3 50/50= Polypropylene

1 - 30/50 + 50/50.L Polypropylene+ 30/50

! I ! i

1 3 7 28

Time, days

Fig. 6.25 - Compressive Strength, f'= vs. Time (Vf = 1%).

8

mm_om_om--

o So¢'

5

_- lume Fraction : 2%3 ET

.... u---- Control2 _ 30/50

Polypropylene1 a 30/50 + 50/50

• Polypropylene+ 30/50I ! ! !

1 3 7 28

Time, days

Fig. 6.26 - Compressive Strength, f'c vs. Time (Vf = 2%).

64

9Type of Fibers: 50/50 Hooked Steel

8 Vf = 1%

7 x- x

am

(n

"_ 5

G;.. 4

--'_--- Control3o Plain FRC

2 -- Latex Modified FRCZ_ Silica Fume Modified FRC

1 • Control+Latex

! I I I

1 3 7 28

Time, days

Fig. 6.27- Compressive Strength, f'c vs. Time, 50/50 Steel Fibers, (Vf=l%)

9Type of Fibers: Polypropylene

8 Vf = 1%

7 ,., -,41" ------t1(

om s

5 - ---_"

u" 4

3 ---_--- Controlo PlainFRC

2 -- LatexModified FRC

1 Zk Silica Fume ModifiedFRC•¢ Control + Latex

O I I 1 !

1 3 7 28

Time, days

Fig. 6.28- Compressive Strength, f'c vs. Time, Polypropylene Fibers, (Vf=1%)

65

Fig. 6.28 provides a comparative evaluation of the effect of latex and silica fume on fc for

the mix containing 1% by volume of polypropylene fibers. None of the mixes with fibers,

microsilica, or latex gave the required minimum 1-day strength of 5 ksi. The strength of the

latex-modified mix was 15%, 11%, 20%, and 2% lower than the silica-fume-modified mix

tested at 1, 3, 7, and 28 days, respectively. Furthermore, the strength of the silica fume

mix was very close to the plain FRC mix over time. The latex mix, however, showed an

average decrease of 30%, 13%, and 23% at 1, 3, and 7 days, respectively. At 28 days, the

increase in fc in both the latex and silica fume mixes over the plain FRC mix was only2%.

6.3.4 Elastic Modulus

The purpose of this section is to compare the variation in the elastic modulus of various

mixes with time and comment on its behavior [5]. It should be noted that the scatter

observed in the elastic modulus tests was much larger than that observed for the

compressive strength tests.

Fig. 6.29 shows a plot of the measured elastic modulus, Ec, versus the square root of the

measured compressive strength, .fc, for all cylinders tested. As expected, except for a few

points, it can be observed that Ec and _c are directly prooortional. The regression line for

the data is given by the following equation:

Ec = - 210,000 + 50,000_c (psi)

The conditional standard deviation of the data is about 460,000 psi, and the coefficient of

correlation is 0.747. The two lines plotted in Fig. 6.29 to bound the data are 1.5 standard

deviations away from the mean and bound 87% of the data.

Fig. 6.30 shows the results of series A mixes using 1% fibers by volume. The 30/50 mix

showed a higher elastic modulus than the control mix at 1, 3, 7, and 28 days. Next in

performance came the hybrid mix with 30/50 + 50/50 fibers. The 50/50 mix showed a

slightly lower elastic modulus. The mixes containing polypropylene showed the lowest Ec,

whereas the hybrid mix containing 30/50 + polypropylene showed a slightly lower Ec value

than that containing polypropylene fibers only. The elastic modulus at 1 day for the 30/50

fibers (Table 6.2) was 7% higher than that of the control mix. However, the elastic moduli

at 1 day for the 30/50 + 50/50, polypropylene, 50/50, and polypropylene + 30/50 mixes

were, respectively, 30%, 30%, 35%, and 40% lower than that of the control mix.

66

600O

o Control e_5000' • AlO/_._

4000 & A1%P0.75

- • AZ,].PO.TS /. ".'11,.'-¢_%_

u,I = A1%S3P0.5• A2%S3P0.5

2000 • B1%S5= Bl%P0.5

= C1%$5

1000 • C1%P0.5• C1%$35

0 ; | f u

0 20 40 60 80 100

Fig. 6.29 - Elastic Modulus, E¢ vs.

67

5000Volume Fraction = 1% ,., -o

4500

400O

3500

•- 3000

2500

o" .... i---- ControlU.I 2000o :30150@ Vf = 1%

1500 o 50/50 @ Vf = 1%

1000 ,, PolypropyleneFibers @ Vf = 1%- 30/50 + 50/50 @ Vf=1%

500 A Polyprowlene + 30/50 @ Vf = 1%

I I I T

1 3 7 28

Time, days

Fig. 6.30 - Elastic Modulus, Ec vs. Time, (Vr = 1%).

o°l /Volume Fraction = 2%6000

5000 t

iiiiI ,..............................2000 1 o 30/50

_oooll :;°oi;"o'°°:';,:o0 1 , _- Polypropylene+ 30/50I I I

1 3 7 28

Time, days

Fig. 6.31 - Elastic Modulus, E= vs. Time, (Vf = 2%).

68

Furthermore, the mixes containing polypropylene fibers showed an increase in Ec up to the

seventh day, then a slight decrease at 28 days. At 28 days, the elastic moduli for the 30/50

+ 50/50 and 50/50 mixes showed no significant changes from that of the control mix.

However, it was observed that the 30/50 fibers gave an Ec value 26% higher than that

given by the control mix, whereas the polypropylene mix and the polypropylene + 30/50

mix gave moduli that were, respectively, 22% and 29% lower than the control mix.

Fig. 6.31 illustrates the results for mix series A containing 2% by volume of fibers. The

30/50 fibers led to no significant change at 1, 3, and 7 days. However, the Ec value at 28

days increased by almost 16% from that of the corresponding control mix. The 30/50 +

50/50 hybrid mix showed a steady increase in the elastic modulus with time, with Ec being

38%, 32%, 16%, and 10% lower than that of the control mix. The elastic modulus of the

polypropylene mix showed no significant change over time, and it was approximately 30%

lower than that observed for the control mix. The polypropylene + 30/50 hybrid mix

showed a sharp increase in Ec at 3 days compared with that at 1 day, whereas little further

change at 3, 7, and 28 days was observed. The Ec value at 1, 3, 7, and 28 days for the

polypropylene + 30/50 hybrid mix was, respectively, 63%, 15%, 25%, and 9% lower than

that given by the control mix.

Other graphs were plotted and analysed. They are shown in Appendix A, Figs. A.112 to

A.120. However, the related conclusions are summarized in section 6.4.

6.4 Conclusions

6.4.1 Stress-Strain Response in Compression

The following conclusions regarding the stress-strain response in compression of

HESFRC composites are drawn:

1. The requirement for HESFRC mixes to achieve a compressive strength of 5 ksi or

greater at 1 day was generally satisfied by the control mix, as well as by all mixes

containing steel fibers. The mixes containing polypropylene fibers and latex did not

satisfy this requirement.

69

2. Reinforcing a concrete matrix with steel fibers significantly enhances the ductility at 1,

3, 7, and 28 days. The control mix without fibers tested at 1, 3, 7, and 28 days

indicates that the mix has no ductility beyond the peak stress.

3. The compressive strengths values obtai:aed at 1 day fi:om the 6 x 12-in. cylinders

ranged from 29% below to 13% above those obtained from the 4 x 8-in. cylinders

(except for one test series that was 58% higher and was discarded from the data). The

average compressive strength for aUmixes at 1 day for the 6 x 12-in. cylinders was

3.9% lower than that obtained for the 4 x 8-in. cylinders.

4. It was generally observed that the presence of polypropylene at 1% and 2% volume

fractions causes a significant decrease in the compressive strength. Doubling the

volume fraction of polypropylene fibers from 1% to 2% causes a significant reduction

in the 1-day compressive strength (-40%). It was concluded that the response of the

polypropylene fiber mix relative to all other fiber concrete mixes was unsatisfactory, in

terms of both strength and ductility.

5. The slope of the descending branch tends to increase with time for almost all mixes of

series A, thus indicating loss in ductility with time. This decreased ductility is believed

to be due to an increase in the compressive strength with time.

6. The 30/50 mix containing 2% steel fibers by volume showed enhanced performance

when tested at all time series in terms of both compressive strength and ductility, which

can be attributed to the enhanced interracial bond properties of the 30/50 fibers

compared with the polypropylene fibers and the better uniformity in distribution when

compared with the 50/50 steel fibers.

7. The hybrid mix containing 1% of 30/50 + 50/50 hooked steel fibers showed a 50%

increase in fc at 28 days relative to the I-day strength. Furthermore, it was observed

that doubling the volume fraction of fibers from 1% to 2% causes a significant decrease

in the compressive strength relative to the control matrix. This decrease was attributed

to the large air voids entrapped in the mix because of the presence of 1% by volume of

50/50 steel fibers.

8. For mix series A, the use of 30/50 hooked steel fibers, 50/50 hooked steel fibers, or a

combination of both causes no significant changes in the compressive strength and

ductility. However, replacing half the 30/50 fibers with an equivalent volume fraction

of polypropylene fibers reduces the 1-day strength by almost 50%, thus significantly

7O

decreasing the area under the stress-strain curve (i.e., lower ductility). Therefore, there

is reason to believe that the presence of polypropylene fibers in any HESFRC mix is

not desirable if meant to improve the compression properties, even at volume fractions

as low as 0.5%.

9. Latex significantly improves the workability of HESFRC mixes, as also observed

previously [3, 4, and 8] but causes a significant reduction in the compressive

properties at early ages. The ductility of the HESFRC mixes containing latex improves

with time because of the improved interracial bond properties latex provides. This was

true when both the steel and the polypropylene fibers were used.

10. Contrary to the results reported in the technical literature for plain concrete, the addition

of silica fume had no significant effect, at early age, on the stress-strain response of the

polypropylene, 50/50, and 50/50 + 30/50 HESFRC mixes containing 1% by volume of

fibers.

6.4.2 Elastic Modulus

The following conclusions regarding the elastic modulus, Ec, of all HESFRC mixes are

drawn from this study:

1. Except for the 30/50 mix at 1% and 2% volume fraction of steel fibers, the elastic

modulus of all mixes was in general less than that of the control mix.

2. As expected, strong correlation was found between measured Ec and measured _[f'c •

3. The 30/50 mix at 1% and 2% volume fractions of steel fibers showed the highest elastic

modulus at all times (1, 3, 7 and 28 days) among all mixes of series A. The increase in

the elastic modulus for this mix relative to the control matrix was more significant at 28

days than at 1, 3, and 7 days.

4. The elastic modulus of the 50/50 and 30/50 + 50/50 hybrid mixes at 1% and 2%volume fraction of steel fibers was less than that observed for the control mix at all

times.

5. HESFRC mixes containing 1% and 2% by volume of polypropylene fibers showed thelowest values for the elastic modulus.

71

6. Latex modification of HESFRC mixes compared with the unreinforced (control + latex)

mix and the plain FRC mix (series A) si_,mificanfly increased Ec as the HESFRC mixes

containing polypropylene or 50/50 fibers aged with time; however, latex addition had

little effect at I, 3, and 7 days.

7. The elastic modulus of all HESFRC mixes plus silica fume containing 1% by volume

of polypropylene, 50/50, or 50/50 + 30/50 fibers was less than that for the control mix

(i.e., plain c 9ncrete mix). A slight improvement was observed for the elastic modulus

of the hybrid (30/50 + 50/50) mix containing silica fume at 1 and 3 days relative to the

plain FRC. However, very little improvement was observed at 7 and 28 days.

6.5 Recommendations

1. The use of 1% to 2% by volume of 30/50 hooked steel fibers gave best composite

properties in both the fresh and hardenexl states. It caused a notable increase in the

compressive strength, elastic modulus, and ductility when compared with all other

HESFRC mixes.

2. Next in performance was the use of 1% by volume of either 30/50 + 50/50 steel fibers

or 50/50 steel fibers. Both mixes performed very similarly in terms of compressive

strength, elastic modulus, and stress-strain response. The 1-day compressive strength

of these mixes exceeded the required rrfinirnum of 5 ksi.

3. Mixes containing 1% to 2% by volume of polypropylene fibers showed deterioration in

the compressive stress-strain response when compared with the control mix. Therefore,

the use of polypropylene fibers alone to improve strength and elastic modulus is not

desirable. However, the use of 1% by volume of polypropylene fibers in conjunction

with 1% by volume of 30/50 hooked steel fibers in the same HESFRC mix leads to a

slight improvement in the compressive stress-strain properties. Polypropylene fibers

may also improve other properties of concrete not tested in this investigation.

4. Although latex improved the workability, of HESFRC mixes, it is not desirable to use

latex with HESFRC mixes for the purpose of improving early age properties.

However, latex improves the long-term compressive stress-strain response of

HESFRC mixes, and is known to improve durability [3, 4, and 8].

72

5. Silica fume had no notable effect on the compressive strength at 1 day. However, it

significantly increased the compressive strength of HESFRC mixes at later ages.

73

6.6 References

1. ACI Committee 318. Building Code Requirements for Reinforced Concrete (AC1318-

83). American Concrete Institute, Detroit, Michigan, 1983.

2. ASTM Standards. Standard Test Method for Static Modulus of Elasticity and

Poisson's Ratio of Concrete in Compression. ASTM C 469-87a, vol. 04.02.

3. Bharyava, J.K. Polymer-Modified Concrete for Overlays: Strength and Development

Characteristics. In Application of Polymer to Concrete, SP-69, American Concrete

Institute, Detroit 1981: 205-218.

4. Mason, J.A. Overview of Current Research on Polymer Concrete: Material and Future

Needs. In Application of Polymer to Concrete, SP-69, American Concrete Institute,

Detroit 1981: 1-20.

5. Naaman, A.E. and F.M. Alkhairi. Fresh and Hardened Properties of High Early

Strength Fiber Reinforced Concrete (HESFRC): Compressive Stress-Strain

Relationship and Elastic Modulus with Time. UMCE Report No. 91-08, 1991.

6. Najm, H. Mechanical Properties of High Performance Cement Based Composites.

Ph.D. Dissertation, Department of Civil Engineering, University of Michigan, 1992.

7. Otter, D. SIFCON Under Cyclic and Monotonic Loading. Ph.D. Dissertation,

Department of Civil Engineering, University of Michigan, 1989.

8. Soroushian, P. F. Aouadi, and M. Naji. Latex-Modified Carbon Fiber Reinforced

Mortar. ACIMaterialJournal, 88, no. 1, (January/February 1991): 11-18.

74

7

Bending Tests


Bending tests were subdivided into three major groups: (1) series A, consisting of

HESFRC mixes having two volume fractions of fibers (1% and 2% by volume of

concrete), two types of fiber materials (hooked steel fibers and polypropylene fibers), and

for the hooked fibers, two lengths, 30 and 50 ram; (2) series B, consisting of HESFRC

mixes containing 1% fibers by volume and 10%latex solids by weight of cemen_ and (3)

series C, consisting of HESFRC mixes containing 1%fibers by volume and 10%

microsilica (silica fume) by weight of cement. Fig. 7.1 shows a flowchart summarizing the

test program. The flowchart is the same as the one used for the compression specimens

(Fig. 5.1), except that a series of tests containing 0.15% by volume of polypropylene

fibers was added, thus changing the total number of series to 17 instead of 16. Flexural

tests were conducted to study the flexural properties of all HESFRC mixes [6], namely, the

load-deflection response in bending.

For the flexural tests, at least two specimens, 4 x 4 x 16 in., were prepared for each

parameter; they were tested at 1, 7, and 28 days (Table 7.1). Average load-deflection and

load-strain curves were compared to clarify the influence of time and various parameters,

such as fiber content, fiber type, and the addition of either microsilica or latex. Specimen

ID notation is shown in Fig. 7.2.

75


Mix Series tFiber Fiber Numberof Beams Tested

Type Type Volume 4 x 4 x 16 in.Fraction Flexural

Vf (%) Test Conducted at (days)1 7 28

HES A Control 0 2 2 2

lIES A 30/50 1 2 2 2HES A 30/50 2 2 2 2lIES A 50/50 1 2 2 2lIES A PP 0.15 2 2 2lIES A PP 1 2 2 2HES A PP 2 2 2 2HES A 30/50 + PP 1 2 2 2lIES A 30/50 + PP 2 2 2 2lIES A 30/50 + 50/50 1 2 2 2HES A 30/50 + 50/50 2 2 2 2

lIES + LA B 50/50 1 2 2 2I-IES+ LA B PP I 2 2 2

I-n=_S+ LA B 30[50+ 50/50 I 2 2 2lIES + SF c 50/50 1 9 2 2HES + SF C PP 1 2 2 2lIES + SF C 30/50 + 50/50 1 2 2 2

Notes: LA = latex; PP = polypropylene; SF = silica fume

76

1D 48 fc 1I

. Specimen Number (1, 2, or 3)


- S = Standard deviation

T.xnt.u£.T.

- fc -- Compressive and elastic modulus

. fr = Flexurai


Size of Cylinder

48 =4 x8in.

612 = 6x 12 in.

Time of Testine

- 1D = 1 day

-3D = 3 days

-7D -- 7 days

.28D -- 28 days


78


7.2.1 Apparatus

The dimensions of the beams were 4 x4 xl6 in. tested in third-point loading, at a span of

12 in., as recommended by ASTM C 1018 [1].

Three types of measurements were recorded for each beam: (1) the load from the load cell

of the testing machine, (2) the vertical deflection at the third points, and (3) the elongation

(strain capacity) measured over a 4 in. gauge length within the constant moment region.

Two LVDT' s were placed under the point loads at opposite sides of the specimen to record

the average vertical deflection. A third LVDT was placed under the beam along the extreme

bottom fiber to measure the elongation within the flexural span. The setup is shown in

Figs 7.3 and 7.4. The load versus average vertical deflection and load versus strain

capacity were recorded via a data acquisition system. It should be noted that the strain

capacity measurement provided information on the strain capacity of a particular fiber

reinforced concrete mix before and after cracking. Also, no correction was made for the

possible deflections (settlements) at the supports, since the supports were very rigid.

The flexural tests were carried out using a 30-kip capacity Instron universal testing machine

using the displacement-controlled method (Fig. 7.5).

7.2.2 Definition of Toughness lndex

Once the load-deflection response in bending was plotted, the toughness index values at

various deflections were computed according to ASTM C 1018 [1]. The toughness index

is a relative measure of the areaunderthe load-deflection curve, and can be correlated with

the energy absorption capacity of the material. The definition of toughness index according

to ACTM C 1018 is illustrated in Fig. 7.6. First, consider the ideal elastic, perfectly plastic

load- deflection response of the top part. The areaunder the curve up to the first cracking

of the beam, or deviation from linearity, is considered the reference area. The deflection at

cracking is termed _first-craek and is used as the reference deflection. The toughness index

up to any deflection 8 > C_m_'t-crackis defined as the ratio of the areaunder the curve up to 8

to the area underthe curve up to 8lust-crack.In the case of an ideal elastic, perfectly plastic

response, the indices I5, I10, and I30 have values of 5, 10, and 30, respectively. The

79

PFromActuator

SpreadBemrn

: !:!-.. ... . .

.... • : ii:i"..:. ::

• .i ... . ..... ..i..• ;:i::. '.:'." , .

: :era: i :;)! '.. .:.. .

4,0" " ".....": " • " ..... .::" :":......,....:: i,_ • '"ii,.:.::,:,:,,,:,._,,' -,i,,,)',;!!i?!,,i,,.i ,::_i.i;,i;,.i: ,, >,::_:,:....•",:.,,:,:.: , " , ,,:::K,i!:,,:,::::;i ': .:..",:" ......

• ,,.,,,, ,:;illI_I.:_,I:: i:i!:_:,,,:,, ,:.;-.:i,,:::,::::! _"_ i ::i:>!i]:::ii:i::i_:.,._.:• ::.... -:_: ._"::i _-:: , ...... _ ":": ....... .. . . .

AttachedFrame

SValnLVDT

Deflection DeflectionLVDT(front) LVDT(back)

I _ | _l, Nl.l_ _1_ _ I_.,_._li-_p-_ l_.,_. r i_.._ .,._i-_ r_l_-- I

2.0" 4.0" 4.0" 4.0" Z.O"

Fig. 7.3- Sketch of the Test Set-up for Flexural Tests

8O

Fig. 7.4 - Test Set-up for the Flexural Tests

81

Fig. 7.5 - Instrumentation Used for the Flexural Tests

82

¢1<o.J

' ,fl

_! ! i i .1 3 5.5 15.5

l DEFLECTION(_ first-crack

< ' ' A0 = I--J I

I !I

II

!!

' CIII!I

' D

I

1 3 5.5

8 l DEFLECTIONfirst-crack

Fig.7.6- Toughness Index in Bending: top) Definition for an ElasticPerfectly Plastic Response; bottom) Typical Curves for FRC

83

deflection at which I5 is measured is three, times the deflection at cracking, _ust-crack. The

deflection at which I10 is measured is 5.58first-crack,and that for which 130 is measured is

15.58f'trst-crack.For a real load-deflection curve, the value of 15 may be smaller or larger

than 5, depending on whether the curve after first cracking falls below the horizontal line or

above it. Hence, in the bottom part of Fig. "r.6, curves A and B have I5 values larger than

5, and curves C, D, and E have 15 values srraller than 5. A similar approach can be

followed to describe the other toughness indices. In the current ASTM C 1018, the

reference deflection and corresponding area under the curve are taken from the same fiber

reinforced concrete test specimen. Howevel, a control plain concrete specimen can be

tested separately, and its area under the curve up to failure can be used as a reference.

These two approaches were followed in section 7.3.4, and led in some cases to

substantially different results.

7.3 Data Analysis and Tests Results

This section summarizes the results obtainecl from the flexural tests: (1) the load versus

deflection and load versus strain capacity at different ages; (2) a comparative evaluation of

the load versus deflection and load versus su'ain capacity relationships for different mixes at

1 and 28 days; (3) the variation of flexural strength with time; and (4) the variation of

various toughness indices with time.

Average strength results and toughness indices are given in Table 7.2. Individual results

for each specimen are summarized in appendix B, Table B. 1, while plots of various time

series and response curves are given in the following sections.

7.3.1 Load versus Deflection and Strain Capacity Response with Time

Here, the effect of time on the load versus deflection and load versus slxain capacity

response of all HESFRC mixes is examined. The effect of microsilica and latex with time is

also studied. Some observations are made, and figures showing the load versus deflection

and load versus strain capacity response obsa_rvedfor each individual specimen and a

representative average curve for each mix are shown.

84

Table 7.2. Summary of Main Flexural Test Results

Mix ID Specimen fr First 15 I5 I 10 I10 120 120ID (psi) Crack First Control First Control First Control

Stress Crack Crack Crack

(psi)

Control 1DfrA 646.88 --- _.......... ,_-.....Control rDfrA '" 600.0 --- [i ........... -- "- - "'" -Control 28DfrA 790.31 ...................A1%S3 1DfrA 937.5 693.8 6.77 9.44 14.00 20.01 23.83 34.38Al%S3 VDfrA 905.25 703.1 8.18 6.68 15.37 12.36 25.12 20.07_d%S3 28DfrA 937.5 750.0 6.73 5.74 11.48 9.66 17.71 14.82_2%S3 1DfrA 1545.0 1312.5 6.45 33.26 9.91 53.77 ......_2%S3 VDfrA 1866.56 1443.8 6.32 15.59 9.47 24.22 12.69 33.06_2%S3 28DfrA 1817.81 1481.3 6.00 13.95 10.14 24.69 .....M%S5 1DfrA 1451.25 637.5 9.66 13.03 23.01 31.58 43.74 60.39A,1%S5 rDfrA 1575.0 956.3 7.69 9.87 16.39 21.39 28.88 37.94_i%s5 28DfrA 1668.75 768.8 9.07 6.88 19.88 14.75 34.44 25.36

_,.15%P0.5 1DfrA 537.19 516 2.16 . 3.1 ...... . ....._,.15%P0.5 7DfrA 787.5 626.3 4.56 2.87 ........... __,.15%P0.5 28DfrA 843.8 843.8 1.7 2.35 ...........

_1%P0.5 IDfrA ....644.06 _..356.3 6.94 11.13 10.56 17.30 .....5_1__%_PP__:_5_....... 7DffA 701.25 300.0 8.73 . 3.23 15.54 5.20. ' 25.25 8.00M%P0.5 28DfrA 938.44 375.0 8.51 3.44 14.24 5.31 22.48 8.00_2%P0.5 1DfrA 459.38 328.1 9.57 4.85 14.12 6.89 24.48 1L54

42%P0.5 iDfrA 619.69 337.5 7...68 3.34 15.14 5.95 25.90 9.724,2%P0.5 28DfrA 632.81 581.3 1.26 3.03 1.44 4.52 1.71 6.68A,1%S3S5 1DfrA 999.38 806.3 3.60 5.33 7.19 11.34 14.22 23.07M%S3S5 VDfrA 1410.94 975.0 3.82 2.50 8.27 4.87 16.94 9.48_t-i%S3S5......28DfrA i321.88 768.8 8.61 8.26 17.26 16.53 27.82 26.61n.2%S3S5 1DfrA 1517.81 1031.3 7.91 33.48 13.81 61.24 22.36 101.43_2%S3S5 iDfrA 1757.81 515.6 9.45 7.62 27.56 21.82 51.78 40.80...._.%S3S5 28DfrA 1912.5 1106.3 8.79 10.96 17.88 22.58 28.52 36.17M%S3P0.5 1DffA 647.81 328.1 10.03 8.01 21.30 16.77 36.85 28.84

1%S3P0.5' 7DffA 770.63 675.0 4.29 7.36 7.43 13.41 11.25 20.80_i%-S31_3.5 28DfrA -909.38 675.0 7.78 5.86 13.81 10A7 21.53 15.70_2%S3P0.5 1DfrA 714.38 300.0 11.11 7.22 24.48 15.45 44.57 27.82_.%S3P0.5 VDfrA 934.69 450.0 10.33 7.05 21.26 14.13 34.30 22.58_2%S3P0.5 28DfrA 1054.69 862.5 8.08 8.33 13.11 13.54 19.80 20.47


85

Table 7.2. Summary of Main Flexural Test Results; continued

Mix ID Specimen fr First I5 15 I 10 110 I20 I20ID (psi) Crack ]First Control First Control First Control

Stress Crack Crack Crack

(psi)B1%S5 __lDfrA, _ 1007.81 _ 890.63 5.21 36.30 8.34 62.55 .....

III II IIII I

B1%S5 7DfrA 1378.13 1125.0 6.27 14.32 11.27 26.97 17.84 43.55B1%S5 28DfrA 1921.88 1312.5 6.93 16.19 13.25 32.35 20.85 51.81B1%P0.5 IDfi'A 575.63 487.50 4.37 3.51 7.73 6.01 13.37 10.20Bl%P0.5 TDfrA 637.5 571.88 4.41 3.38 7.78 5.73 12.00 8.68B1%P0.5 _SDfrA 871.88 750.00 4.40 2.76 7.66 4.46 12.49 6.96B1%S3S5 IDfrA 1013.44 825.00 6.20 17.04 10.97 31.72 16.60 49.07B1%S3S5 7DfrA 1406.25 1078.1 6.79 12.06 12.86 23.67 20.38 38.03B1%S3S5 _SDfrA 1753.13 1368.8 6.09 14.82 10.70 27.32 16.01 41.75C1%$5 IDfrA 1228.13 1087.5 5.71 26.51 10.63 53.15 17.72 91.51_!%S5 _7DfrA __1449.38 1125.0 6.45 12.83 11.93 24.75 18.42 38.84C1%$5 28DfrA 1978.13 1312.5 7.10 11.85 13.39 23.04 20.23 35_1

21%P0.5 1DfrA 553.13 421.88 5.6 5.57 9.49 9.42 14.07 13.97

21%P0.5 7DfrA 648.75 365.63 I 4.61 3.01 7.,56 4.66 11.13 6.6521%P0.5 28DfrA 787.5 581.25 1.16 2.17 1.38 3.75 1.68 5.94

C!%$3S5 1DfrA 984.38 796.88 6.31 17.25 11.69 33.74 18.40 54.27C1%$3S5 7DfrA 1425.0 843.75 7.74 8.62 15.94 17.88 26.90 30.28C1%$3S5 28DfrA 1350.0 1031.3 6.74 7.59 11.79 13.39 18.71 21.33

86

• No significant change in flexural behavior was observed with increasing age for the test

series containing 1% by volume steel fibers, hooked 50/50 and 30/50 (Figs. 7.7 and

7.8, respectively)

• When 2% 30/50 hooked steel fibers are used, the ductility at seven days increases

significantly compared with that at one day. However, there is little change in the

response at 28 days compared with that observed at seven days (Fig. 7.9).

• The use of polypropylene fibers at Vf = 0.15% does not influence the bending strength

of the HESFRC mixes. Corresponding specimens showed brittle failure at the onset of

cracking (i.e., sudden drop in the load-carrying capacity), with little crack distribution

along the beam. Furthermore, the beams showed little strain capacity before failure

(Figs. 7.10 and 7.11).

• The use of polypropylene fibers at Vf = 1 and 2% also did not lead to any significant

enhancement in bending strength for all time series tested. The failure at 7 and 28 days

was brittle and somewhat similar to that observed for the mix containing 0.15% by

volume of polypropylene fibers. It can be generally concluded that the presence of

polypropylene fibers at low volume fractions (e.g., less than 1%) does not significantly

enhance the fiexural strength compared with the control mix, wheras the use of higher

amounts of polypropylene fibers (e.g., 2%) causes a significant decrease in the flexural

strength. This decrease is perhaps due to the difficulty in mixing 2% by volume of

polypropylene fibers, which may lead to entrapped air and increased porosity. For all

mixes containing polypropylene fibers, it was observed that the first cracking load also

is normally the maximum flexural load sustained by the specimen (Figs. 7.12 and

7.13, respectively).

• The 30/50 + 50/50 mix containing 2% by volume of hooked steel fibers showed

enhanced behavior at 1, 7, and 28 days. Although no significant change was observed

in the ductility of this mix between 1 and 28 days, the flexural strength increased by

almost 15% at 7 days and 20% at 28 days (Figs. 7.14 and 7.15).

• The addition of latex also improved the response with time of the mixes with

polypropylene fibers and the hybrid mixes (30/50 + 50/50) containing 1% fibers by

volume (Figs. 7.16 and 7.17).

Other graphs were plotted and analyzed. They are shown in appendix B, Figs. B. 1 to

B. 16. However, the related conclusions are summarized in section 7.4.

87

c5

oq FRC - Fiexur_t Test _t I,7, _nd 28 days50/50 Hooked Steer Fibers

o_ VF = I;:

rC

_o-,_i ,i ...............I d_gV

<_ _- _'_..

_.1 c,i

M

.O0 ,10 .PO .30 ,40 .50 .60

DEFLECTIDM (;n>

Fig. 7.7 - Effect of Time on Load vs. Deflection Response, 50/50 Steel Fibers, (Vf=l%)

_'- F'RC - Ftexurat Test at 1, 7, and 28 days

c_- 30/50 Hooked Steer Fibers

_C% _ - VF = I%

vi,-.,.._. - - - 7 d_y i

.00 ._0 .eo .30 .40 .50 .soDEFLECTIDM (in)

Fig.7.8- EffectofTimeonLoadvs.DeflectionResponse,30/50SteelFibers,(Vf=1%)

88

FRC - FLexurat Tes_ a_ l, 7, and 28 days

a_ 30/50 Hooked $_ceel Fibers

u_In r___ 1 day

t •

•. - - - 7 d,_y

l::::l 16 \_""-. ;)8 dayI: I '.

tl_ I: • '.

$ "

._j t% °.o

(_ • m.,• q... ;.

_j -..._..:

.00 .10 .Z0 .30 .40 .50 .60

DEFLECTInM (in)Fig. 7.9 - Effect of Time on Load vs. Deflection Response, 30150 Steel Fibers, (Vf=2%)

O_ FRC - FLexur_t Tes_ a± 1,7, _nd 28 da_sI/2" Potypropytene Fibers

0_ Vf' = 0.157.

r< i d_y

,_ ...............7 _sV

28 d_ys

[]

-J ri

.00 .10 .ao .30 .40 .so .60DEFLECTIDM (in)

Fig.7.10- Effectof Timeon Loadvs.DeflectionResponse,1/2" PolypropyleneFibers,(Vf--O.lS%)

89

¢5

o_- FRC - Flexurat Tes_c _ i, 7, ond 2B dogs

- I/2' Poiypropyiene Fibers

o_- V? = I).15%

rx g%_-Ul

_el,__ i _Qy

-- ..................7 d_ys

<_ _r --, - • - 2B d_js[] _ si,

-%. CQ

M

I I I I I I I I I.oo .o3 .o6 .o9 .12 .15

STRAIN CAPACITY (in/in)Fig. 7.11 - Effect of Time on Load vs. Strain Capacity Response, 1/2" Polypropylene

Fibers, (Vf=0.15 %)c_

o_- FRC - F'(exurQt Test _t I,7, _nd 28 d_ys

- I/2' Poiypropy|ene Nix0_- V? = I;:

r_ -ffl

_-

u_ .... 7 d_y

---- 2B d_g

n

_ .....

ib"

I I I""" I I !: I 1 I I I.00 .I0 .20 .30 .40 ,50 ,60

DEFLECTION (in)

Fig. 7.12 - Effect of Time on Load vs. Deflection Response, 1/2" Polypropylene Fibers,

(Vf=l%)

9O

o_ - F'RC - F'texur'ot Tes't ot: 1, 7, nnd 28 do.ys- 1/2" Potyropytene HIx

a_- VF = 2_.

CL _ ...............! day

_. ---7days_-- _ 28 days

%.

.00 .10 .;:)O .30 .40 .SO .60

DEFL.ECTII'IH (in)

Fig. 7.13 - Effect of Time on Load vs. Deflection Response, 1/2" PolypropyleneFibers, (Vf=2 %)

91

.

FRC - Flexura[ Test at I,7, and ;28daysHybrlclNlx

o_ 30/50 + 50/50 Hooked Steel Fibers

v? = 2%f%

U_ :; ".EL r< -,

__ "J I dayv _ i' ................," - - - 7 dag"i

u_ _; ---- 28 dag<:[

(9_ "''.....o

I I I I I I I.00 .lO .20 ,30 .40 .50 ,GO

DEFLECTION (in)

Fig. 7.14 - Effect of Time on Load vs. Deflection Response, 30/50 + 50/50 Steel Fibers,(Vf=2%)

i

c5- FRC - l:IexuraITest _t I,7, _nd 28 days

Hgbrld Mixo_ ,,- -', _ 30/50 + 50/50 Hooked Steel. Fibers

• ... _

Ul " " ...............1 day

-- .... - - - 7 dayY

v ,,_ - ....,,,,._,__. _ 28 d_y

_1r_

o.i-

,__ -

I I I I I I I I i.00 .03 ,06 ,09 .1P ,15

STRAIH CAPACITY (;n/In)

Fig. 7.15 - Effect of Time on Load vs. Strain Capacity Response, 30/50 + 50/50 SteelFibers, (Vf=2 %)

92

o_ F'RC - FLexur'Qt Tes_ a_ L 7, and 28 days!La*cex Mix

06 30/50 + 50/50 Hooked S_eet FibersVf = LX

,_ r_U_ ", ............. 1 day

Y , - - - 7 daq%,# -. •

.o'° •._ : " , __ Z8 day

• %

,. %%

<C _r ... ,,tlm3 °.. •

r_ ""..°.° •_,

•-.. ......... . ...... ...

.oo .zo .eo .30 .40 .so .60DEFLECTIE]I'I (in)

Fig. 7.16 - Effect of Time on Load vs.Deflection Response,Latex,30/50 + 50/50 Steel Fibers, (Vf=]%)

c_m

FRC - Ftexurat Tes_ a_ L 7, and 28 daLjso_ m

m/-- \ La,x .,x06-/ "_ 30/50 + 50/50 Hooked $'_ee[ Fibers

L -.. _ - - - z _,ay"-,.. __ ..,-,,,Y

_' _ rE....'"""'""...... _

_ .." ".... ".<[ ,:- ".... ",,rJ'1 w- o., •

I _: "'"'""'"'""" ........ •"•""•"-

_ ,°°°°°o°

..... ....°

_ -

I i I I I I I I I.00 .03 .06 .09 .la .15

STRAIN CAPACITY (in/in)

Fig. 7.17 - Effect of Time on Load vs. Strain Capacity Response, Latex,30/50 + 50/50 Steel Fibers, (Vf=l%)

93

7.3.2 Load versus Deflection Response: Comparison between Series

This section compares the load versus deflection response for beams made from different

mixes at 1 and 28 days. Only typical examples are discussed in this section. However, the

graphs developed for all parameters are included in appendix B, Figs. B.17 to B.20, and

the related conclusions are presented in seclion 7.4.

• The mix containing 1% by volume of 50/50 steel fibers showed the highest flexural

strength and ductility at 1 day, compared with the mixes with 30/50 steel fibers and

with polypropylene fibers. This can be atu'ibuted to the improved mechanical behavior

of the 50/50 hooked steel fibers, compared with the 30/50 and polypropylene fibers.

The mix with the 50/50 fibers showed average increases of 35 and 150% in the

flexural strength relative to the mixes with 30/50 and polypropylene fibers, respectively

(Fig. 7.18).

• When compared with other hybrid mixes containing 1% by volume of fibers, the 50/50

mix still showed superior load versus deflection response. The 30/50 + 50/50 mix

showed a slight improvement in behavior relative to the 30/50 mix (7% increase). The

behavior of the 50/50 mix was much better than that of the 30/50 + polypropylene mix;

however, the latter was slightly better than the polypropylene mix (Fig. 7.19). It can be

concluded that the presence of polypropylene fibers in HESFRC composites is not

desirable if flexural strength is to be improved.

• At 28 days, the 50/50 mix showed much higher ductility in comparison with all other

plain and hybrid FRC mixes containing 1% by _/olume of fibers (Figs. 7.20). The

flexural strength of the 50/50 mix was 45% higher than that of either the 30/50 or the

polypropylene mix. The polypropylene and 30/50 mixes showed similar flexurai

strength capacities; however, the ductility of the 30/50 mix was much better than that of

the polypropylene mix (Fig. 7.20).

• The 50/50 mix outperformed the 30/50 + 50/50 hybrid mix (23% flexural strength

increase) at 28 days. Both 30/50 and 30/.50 + polypropylene mixes showed a 50%

reduction in the flexural strength compared with the 50/50 mix. These mixes also

showed poor ductility relative to the 30/50 + 50/50 and the 50/50 mixes (Fig. 7.21).

• At one day, the behavior of the mix conlatining 2% by volume of 30/50 fibers was

much better than that of the polypropylene mix containing the same percentage of

fibers. The mix with polypropylene fibers showed 30 and 70% reductions in the

94

m

o_- Plain FRC - Fiexural Test at I dayl Comparative Fva[uatlon

o_- , of Different Mixes- ,'", VF = 17.

m | •

. I _

,,,, 4.x ,.x. __ ", _ Control

U'J I ._. _-,-" ". -. ...............30/50 Hooked SteerI" " •

_F _ ". "'-, _ m --50/50 Hooked Steer

H' ";"4 """. . 1/2 ' Potypropytene

%, %_%

.00 .10 .20 .30 .40 .50 .60

DEFLECTION (in)

Fig. 7.18. Load vs. DeflectionResponsefor Different Mixes, 1 Day,Plain FRC, (Yf=1%)

o_- Plain L Hybrid FRC - FLexure| Test- at I day. Comparative Evaluation- of DIFFerent Mixes

- .'""'". VF = IZ. . . ,I_- ." '. Motd size= 4 x 4 x 16

_/_ - _Controtm

m '.... : 30/50 Hooked Steer

_--_ I-:,"• "''. ..............50/50 Hooked SteerU_ : t ".P-;." L_

r-u_l:;a"_" '-.. ---30/50 + 50/50 Steer_ I-_ _-', "'" .... . 30/50 Hooked FIIoers +

"q_', "'""-.. 1/2' PoLypropI,jtene

CO %_-. "'"......

,.4

.00 .10 .20 .30 .40 .50 .60

DEFLECTIOH (in)

Fig. 7.19 - Load vs. Strain Capacity Responsefor Different Mixes, 1 Day,Plain and Hybrid FRC, (¥'f=1%)

95

o_- ,, Plain FRC - Ftexurai Test at 28 days- ; , Conparatlve Evaluation

O0- _ ', oF DIFFerent HlxesI t

- : ,, v_ = Ix_l-: ",

L-l ', Moldsize, 4' x 4" x IS'- I _ ', _ Control

ID !--;. I_:t" ', ............. 30/50 Hooked Steel

,_t4ii':- ',, - - -50/50 HookedS_eeLI: " •

m I-;.:/11 "--...... - ,,,, .

.00 .10 .20 .30 .40 .50 ,60DEFLECTIBH (in)

Fig.7.20 - Load vs.DeflectionResponsefor Different Mixes,Z8 Days,Plain FRC, (Vf=l%)

o_ Plain I, Hybrid FRC - Flexural Test

b :"""" at ;)8 dauJS. Comparative Evaluation

I-- / "" oF DIFFel-ent Mixes

E/ . v,,=,zi ,, "-.

_f / ", Hold size, 4" x 4' x 16"

Fi/ "',- :o.trolI-i, , ,. * 30/50 Hooked Steel

L_l_L ,,".. ...............50/50 Hooked Steel• ,%,

L"J_-_ ",". - - -30/50 + 50/50 Steel

"; " ......I I I.00 .10 .a0 .30 .40 .50 .60

DEFLECTInH (in)Fig. "7.21- Loadvs.StrainCapacityResponsefor Different Mixes,28 Days,

PlainandHybrid FRC, (Yf=I%)

9d

flexural strength relative to the control mix and the mix with 30/50 fibers, respectively

(Fig. 7.22).

• The 30/50 and 30/50 + 50/50 hybrid mixes showed about the same flexural strength.

However, the 30/50 + 50/50 hybrid mix showed higher ductility than the 30/50 mix.

This suggests that although the 30/50 fibers may contribute equally to strength, the

presence of 50/50 fibers in the hybrid mix significantly enhances ductility (Fig. 7.23).

Figure 7.23 also suggests that eventhough replacing 1% of 30/50 fibers in a mix

containing a total of 2% by volume of fibers with an equivalent volume fraction of

50/50 fibers enhances ductility, the opposite is observed when 1% by volume of

polypropylene fibers is used. The use of 1% by volume of polypropylene fibers in

combination with 1% by volume of 30/50 fibers leads to a reduction in flexural strength

of about 55% compared with the use of 2% by volume of 30/50, or 30/50 + 50/50

fibers.

• The use of 2% by volume of polypropylene fibers compared with the 30/50 steel fibers,

shows significant deterioration in both strength and ductility at 28 days. The strength of

the mix with polypropylene fibers was about one-third that of the mix with 30/50

fibers. Furthermore, the failure of the polypropylene fibers specimens at 28 days was

sudden with little or no crack distribution before first cracking (Fig. 7.24). The overall

response of the specimens with the polypropylene fibers may have also been affected

by the large amount of air entrapped duringmixing.

• The 28-day load versus deflection response of the specimens with 2% by volume of

30/50 fibers was similar to that of the specimens with 30/50 + 50/50 fibers. The 30/50

+ 50/50 mix showed a slight improvement in ductility relative to the 30/50 mix because

of improved mechanical behavior of the 50/50 fibers. The 30/50 + polypropylene

hybrid mix showed a significant reduction in both strength and ductility compared with

either 30/50 or 30/50 + 50/50 mixes (40%). It is believed that this may be due to the

presence of air voids entrapped during mixing of the polypropylene fibers (Fig. 7.25).

• The addition of latex led to about a 30% reduction in the one-day flexural strength of

the 50/50 mix, when compared with plain FRC. Also, the addition of silica fume to the

50/50 mix did not significantly affect the strength or ductility at one day (Fig. 7.26).

• The 28-day flexural load versus deflection response of the 50/50 mix containing either

latex or silica fume showed increases of 15 and 10%, respectively, in flexural strength,

97

c_e-I

B

o_ - Pl=In FRC - Ftexurat Test ,,t ! day- CompQratlve Evatu(_'t;lon

00- _.- of' DIFFerent Mixes- V'_' = 2Z

._. _ -L_

._ : Hol,d size, 4" x 4' x 16'" _ Controt

- •..............30/50 Hooked Steel

<I: _ .... I/2' Potypropylene!-1

-.I _ "'._

... .....

I I I I .... 4..... I I I I I I.0c .zo .20 .30 .40 .so .co

DEFLECTIOM (in)Fig. 7.22 - Load vs. Deflection Response for Different Mixes, 1 Day,

Plain FRC, (Vf=2 %)

om

o_ - Ptnln& H_jbrld FRC - Ftexur_t Test- _t I day. Comparative Ev_tuation

- .'_.."-, of DifFerent Mixes

, V_ = 2"/.I_ -- i "-

_/_ --_ "- "' Motd size, 4' x 4' x 16'

v_ ,,O- tl :' ", -- Control.-:-'" ._. ", '.............30/50 Hooked SteerI/3 --"" ; •

_! :. ", - - -30/50 + 50/50 Steer

_: -ii ". ", . 30/50 Hooked Fibers *l" : •

mNf N ..... ..

,00 .10 .;=0 .30 .40 ,50 ,60

DEFLECTIDN (an)

Fig. 7.23 - Load vs. Strain Capacity Response for Different Mixes, 1 Day,Plain and Hybrid FRC, (Vf=2%)

98

d PialnFRC - Ftexurai Test at 2B da_s

Comporatwe Evotuatlono_ " oF rllFFerent HIxes

VF = 2%O_ :

U_O. _

Hold size, 4' x 4' x 16'v _ -- Contr'ot

u_ : ...............30/50 Hooked Steel

<_ - - - I/2'Potypropytene

"!D 'q"._1

ei

° •

,00 .10 .20 .30 .40 .50 .GO

DEFLECTION (in)Fig. 7.24 - Load vs. Deflection Response for Different Mixes, 28 Days,

Plain FRC, (Vf=2%)

- , Plain 8, Hybrid FRC - Flexurai Test

.- ]"..;',, at 28 days. Comparative Evaluationm- It - , oF DiFFerent Hlxes

=_/ , \ vF =a%

I_-_ ".. ", Mold size, 4' x 4' x 16'

_ "...',, __ co,_ot[-_/¢_ "... ", ...............30/50 Hooked SteelI_ \ ,, - - -3o,5o+5o,5os_,+_

.1,9, "_ "...",. - 30/50 Hooked Fibers +

"".."'-.... 1/2' Polypropylene

,00 .10 ,PO .30 .40 ,50 .60

DEFLECTIDM (in)

Fig. 7.25 - Load vs. Strain Capacity Response for Different Mixes, 28 Days,Plain and Hybrid FRC, (Vf=2%)

99

o_- FRC - Ftexurot Test at I day- Cc,mporatlve Fvatuatlon

0_- 50/50 Hooked Steel Fibersm .'""

:" '. Vt: = IX

:' , "'.. Hold size, 4' x 4' x 16'[-# r-<'-,., :o.,ro

l-+,'/ "-.. +'++-+ - "o-x1_1 ei .....:..

ai

M

.00 ,I0 ,eO ,30 ,40 .50 .60

DEFLECTION (in)Fig. 7.26 - Effect of Additive on Load vs. Deflection Response, 1 Day,

50/50 Steel Fibers, (Vf=l%)

FRC - Fiexurat Test at 28 days

Comparative Evaluationo_ 50/50 Hooked S'l;eetFibers

VF = 1X'.

" Mold size, 4' x 4' x 16'n rC: '.-- "- -- Control

"v _ • _ ...............P|aln FRC

%

'+ - - - SILICoFume

<I_ "' * Latex

"O°°o. ,_

0+ .......................__:.,.:.-.:.:

I I I,00 ,I0 .20 .30 .40 .50 .60

DEFLECTIDM (in)

Fig. 7.27 - Effect of Additive on Load vs. Strain Capacity Response, 1 Day,50/50 Steel Fibers, (Vf=1% I

100

compared with the plain FRC mix. The mix with latex showed higher ductility than

either the plain FRC mix or the FRC mix with silica fume (Fig. 7.27).

7.3.3 Modulus of Rupture or Maximum Flexural Strength

The purpose of this section is to discuss the modulus of rupture (MOR), symbol fr, for

different mixes and time series. The MOR was calculated for each individual specimen, as

well as the average value for each time series. Table 7.2 summarizes the average flexural

strength values obtained for each time series, and Table B. 1 of appendix B summarizes the

data observed for each individual specimen as well as the average value for each time

series. Plots were also obtained for the variation of MOR, fr, with time, comparing various

mixes.

• For mix series A containing 1% fibers by volume, the 50/50 mix outperformed all

others in terms of the MOR. The use of 50/50 fibers increased the 1-, 7-, and 28-day

flexural increases in strength for this mix at 7 and 28 days relative to the 1-day strength

were 10 and 15%, respectively.

• The use of 1% by volume of polypropylene fibers did not change the 1-day flexural

strength relative to the control mix. However, it did cause a slight increase in the 7- and

28-day strengths (17%) ( Fig. 7.28).

• Compared with the control mix, the following changes in fr were observed for the use

of 1% of polypropylene, 30/50 + polypropylene, 30/50, 30/50 + 50/50, and 50/50

fibers: (1) 0%, 0%, 45%, 55%, and 125% increases in the 1-day strength; (2) 18_,

28%, 51%, 135%, and 163% increases in the 7-day strength; and (3) 19%, 15%, 19%,

67%, and 111% increases in the 28-day strength (Fig. 7.28).

• A significant deterioration in the fiexural strength was observed for all time series of the

mix containing 2% by volume of polypropylene fibers (Fig. 7.29).

• The mixes containing 2% by volume of 30/50 and 30/50 + 50/50 fibers showed the

highest fiexural strength at 1, 7, and 28 days compared with all other series A mixes

(Fig. 7.29).

I01

180O

1600 .....____=_=/=....---

1400'.. f_-

1200"

"_,--10oo o _ -

800- -'=

600" &--"_-" ............ _.................

400".... "*'--" Control = PolvDroDvlenefibers

200- :" 30/50 • 30/50 + 50150a 50/50 J. Polypropylene+ 30/50

01 7 28

Time, days

Fig. 7.28 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=1% )

2000• _

1800 - __"_.r-""_ o

1600"

1400

em

(n 1200

Q" 1000=.--- 800

"r_''" - i-1

600"

400" ---a Polypropylenefibers.... ,,--- Control :- 30/50 + 50150

200o 30/50 - Polypropylene+ 30/50

! | !

1 7 28

Time, days

Fig. 7.29 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=2%)

102

Only typical curves were shown and discussed in this section. The remaining graphs,

including all parameters studied, are presented in appendix B, Figs. B.21 to B.29, and the

related conclusions are summarized in section 7.4.

7.3.4 Toughness Index

The purpose of this section is to summarize the analysis performed on all beams involving

the calculations of various toughness indices. The results are presented in tabulated (Table

7.2) and graphical forms. Toughness indices are calculated as a means of evaluating the

flexural toughness or energy absorption capacity of FRC in terms of the area under the load

versus deflection curve. The def'mition of toughness index is given in section 7.2. Two

methods of computation were used in this study. In one, the reference deflection is taken as

that of the unreinforced control mix. In the other, the reference deflection is the deflection

of first cracking of the specimens being tested (ASTM C 1018) [1].The toughness indicesare defined as follows:

• Is-co:the ratio of the area under the load versus deflection curve up to three times the

maximum deflection attained by the control mix, dco, divided by the area under the load

versus deflection curve up to dco

• I10-co: the ratio of the area under the load versus deflection curve up to 5.5 times the

maximum deflection attained by the control mix, _eo,divided by the area under the load

versus deflection curve up to _co

• IN-co: the ratio of the area under the load versus deflection curve up to 10.5 times the

maximum deflection attained by the control mix, _o, divided by the area under the load

versus deflection curve up to _co

° ISlst-CR: the ratio of the area under the load versus deflection curve up to three times

the first-crack deflection, 151stCR,divided by the area under the load versus deflection

curve up to _ilstCR in accordance with ASTM C 1018-89

° I101st-CR:the ratio of the area under the load versus deflection curve up to 5.5 times the

first-crack deflection, 151stCR,divided by the area under the load versus deflection curve

up to 81stCRin accordance with ASTM C 1018-89

103

• I201stCR:the ratio of the area under the itoad versus deflection curve up to 10.5 times

the f'trst-crack deflection, _ilstCR,divided by the area under the load versus deflection

curve up to _lstCR ill accordance with ASTM C 1018-89.

It should be noted that the toughness indices were calculated using the average load versus

deflection relationship of each time series. The following observations were made:

• In general, toughness indices calculated using as a reference the deflection at failure of

the control mix showed a consistent trend, wheras those calculated using the first

cracking load showed no consistent trend, since the onset of ftrst cracking may be quite

subjective.

• Iseoand I10co for all mixes steadily decreased with time up to day 28. However, the

IS-lstCR and I10-1stCRdid not show a consistent trend (Figs. 7.30 through 7.33 ).

• The addition of latex to the mixes with 1% 50/50 and 30/50 + 50/50 showed a

significant drop in the Is-co and Ilo-_ values up to day 7, thereafter slightly increasing

up to day 28 (Fig. 7.34 and 7.35). The modification of the polypropylene mix with

latex showed a steady decrease in the Is-co and I10-covalues (Fig. 7.36). All three

mixes showed no significant change in the IS-lstCR and I10-1stCRvalues.

• The addition of silica fume to the 50/50 mix led to a sharp drop in the I10-coup to day 7

(55%) and a milder drop up to day 28 (15%). IS-lstCR and I10-1stCRshowed no

significant change at any time. (Fig. 7.37).

• Fig. 7.38 shows a decreasing I20-cowith time for all mixes containing 1% by volume

of steel fibers (series A). Fig. 7.39 shows the variation of I20-1stCRfor the same

mixes. It can be observed here that the method for computing the toughness index,

based on the first cracking load, does not lead to a consistent trend.

• Fig. 7.40 shows the general trend of ductility loss with time for all series A mixes

containing 1% by volume of fibers and using Is-co. The polypropylene mix showed the

sharpest drop in Is-co compared with other mixes.

• Fig. 7.41 describes the same mixes as Fig. 7.40 except that the ductility is measured

using IS-lstCR. Again, unlike the Is-co, I5-1stCRshows no consistent trend for the

variation of ductility with time.

104

30Type of Fibers:

30/50 Hooked SteelVf = 1%

--,o-- 15-1stCR-- o 15-CO

. 20 _ --4=-- I10-1stCRx_- = 11O-CO"0

c 10

k-

0 i i ¢

1 7 28Time, days

Fig. 7.30 - Toughness Index Is and Iio vs. Time, 30/50 Steel Fibers, (Vf-l%)

60 Type of Fibers:30150 Hooked Steel

50 Vf = 2%

. --,o-- 15-1stCR

x" = 15-CO40'

•o --g-- ll0-1stCR: I10-CO

30'w

e-,,¢o= 20

o1-

10 • m-.......... -4c- ........ -8- ....... ,

i ! i

1 7 28Time, days

Fig. 7.31 - Toughness Index Is and Ilo vs. Time, 30/50 Steel Fibers, (Vf=2%)

105

40Type of Fibers:

50/50 Hooked SteelVf = 1%

" 30 _ -- .o-- 15-1stCR

" _ = 15-C0

x--4'-- I10-1stCR"o

= -- _ ; I10-C0

e,-c-

O 10 ........I'-

0 I 1 I

1 7 28Time, days

Fig. 7.32 - Toughness Index Is and llo vs. Time, 50/50 Steel Fibers, (Vf=l%)

20 Type of Fibers:112" Polypropylene

Vf = 1%

e-

gg

1 7 28Time, days

Fig. 7.33 - Toughness Index Is and I1o vs. Time, 1/2" Polypropylene Fibers, (Vf=1%)

106

70 Type of Fibers:50150 Hooked SteelIL

60 _ Vf = 1%,%

Chemical Addltlve: Latex,. 50 _ --.e-- 15-1stCR,; _ = 15-com _ I -- _ I ! I10-1stCR•o 40

_ 3offl

C

•_ 20

I-- 10 =..........mNmm O

0 I I I

1 7 28

Time, days

Fig. 7.34 - Toughness Index Is and Izo vs. Time, 50/50 Steel Fibers, Latex, (Vf-l%)

40Type of Fibers:

30150 Hooked Steel +50150 Hooked Steel

30 __- lY,o Chmlecal Addltlve:jLatex

xI l 40 I I 15"lstCR

"o = 15-C0--- 20 --a-- I10-1stCR_ COmWt-

_ 10-10 _ ....... _ oj,-

I I I

1 7 28Time, days

Fig. 7.35 - Toughness Index Is and Izovs. Time, 30/50 Steel + 50/50 Steel Fibers,Latex, (Vf=1%)

107

8B" IP ,111

Type of Fibers:7 1/2" Polypropylene

Vf = 1% --,o-- 15-1stCR.- Chemical Additive: Latex = 15-COx" 6 __.__L ----4=---- I10-1stCR=) - I10-C0

° 5

C,- 4

_ ¢ ,

°I- 3

i ! i

1 7 28

Time, days

Fig. 7.36 - Toughness Index Is and Ilo vs. Time, 1/2" Polypropylene Fibers,Latex, (Vf=l%)

60Type of Fibers:

____ 50150 Hooked Steel

50 Vf = 1%., Chemical Additive:- Silica Fume

X¢_ 40"O --,o-- 15-1stCR¢= = 15-C0

u_ 30 --4= -- I10-1stCR= I1O-CO

" 2001

oI-- 10 _" ......O-

0 ! i i

1 7 28

Time, days

Fig. 7.37 - Toughness Index I5and Ilo vs. Time, 50/50 Steel Fibers,Silica Fume, (Vf=1%)

108

70

o 30/50

60 %,. = 50/50-- 30/50 + 50/50

50 = Polypropylene + 30/50

o 40

o30

2O

10

! ! I

1 7 28

Time, days

Fig. 7.38 - Toughness Index I2o -co vs. Time for Different Mixes, (Vf=1%)

5O

= 30/50* 50/50

,. --- 30/50 + 50/50

,.,- 40 __30/50

o,

o 3O

-20

10 , , ,1 7 28

Time, days

Fig. 7.39 - Toughness Index I2o -lst-CR vs. Time for Different Mixes, (Vf=1%)

109

2O

--_' 30/50 1

50/50Polypropylene Fibers

15 % = 30/50 + 50/50 .. "_ " " Polypropylene + 30/50 c

fO 10 =

It}

-

! ! i

1 7 28

Time, days

Fig. 7.40 - Toughness Index I5 -co vs. Time for Different Mixes, (Vf=l%)

11:- " 30050

= " 50/50

I0 ._k = _- Polypropylene Fiberss

: Polypropylene + 300509' \_ • - 30/50+50'SO

e¢

o, 8g'J

7

6

5

i i j

1 7 28

Time, days

Fig. 7.41 - Toughness Index I5 -1st-ca v_ Time for Different Mixes, (Vf=l%)

110

• Fig. 7.42 shows the variation of I5-co with time for mix series A containing 2% by

volume of fibers. The figure suggests that although the 30/50 + 50/50 mix showed a

sharp loss of ductility at 7 days relative to 1 day, all other mixes showed no significant

change in I5-cowithtime.

From the above study, it can be generally concluded that the use of the area under the load-

deflection curve of the control mix, as opposed to using the area under the load-deflection

curve up to first cracking, leads to more rational and consistent results for ductility indices

[2,3,4,5, and 7].

Similar graphs were plotted and analyzed for all the other test series. They are included in

appendix B, Figs. B.30 to B.39. However, conclusions drawn from the test results aresummarized in section 7.4.

7.4 Conclusions

This section summarizes the main results of this part of the experirnental investigation

which dealt with the flexural properties of High Early Strength Fiber Reinforced Concrete

(HESFRC) subjected to static flexural loading. General conclusions are drawn from the

results obtained, and some recommendations with regard to optimal mixes for bending

properties are suggested.

The following conclusions regarding the response of all HESFRC composites in flexure

were arrived at:

1. The load versus deflection response of the mix containing 1% volume fraction of 50/50

fibers does not change significantly with time. However, the one-day flexural strength

of the composite was about twice that of the control mix.

2. For a volume fraction of fibers Vf = 1%, the use of 50/50 instead of 30/50 steel fibers

led to a 70% increase in the flexural strength.

3. Using 2% by volume of 30/50 fibers instead of 1% causes the flexural strength to

increase about twofold. It was not possible to properly mix 2% by volume of 50/50

fibers with the matrix specified for HESFRC mixes.

111

40

= 30/50

= PolypropyleneFibers30 _ - 30/50 + 50/50

o _" Polypropylene+ 30/50rj

2O

Iml

lO '0

! i !

1 7 28

Time, days

Fig. 7.42 - Toughness Index Is -co vs. Time for Different Mixes, (Vf=2%)

112

4. Using polypropylene fibers at very low volume fractions (i.e., Vf = 0.15%) does not

change the tensile properties of the composite when compared with the control mix,

wheras using polypropylene fibers at volume fractions as high as 2% will generaUy

result in a deterioration in the tensile properties, compared with the control mix. This

deterioration is primarily due to mixing difficulties that lead to an increase in entrapped

air. Further, the use of polypropylene fibers in HESFRC mixes did not lead to a

sufficient post cracking strength at seven and 28 days.

5. Mixes containing polypropylene fibers exhibited very low strain capacity before the

peak load in comparison with mixes containing steel fibers or a combination of

polypropylene and steel fibers.

6. In mixes containing 2% fibers by volume, the replacement of 1% of 30/50 hooked

steel fibers by an equivalent amount of polypropylene fibers led to lower flexural

strengths. However, replacing the same amount with 50/50 hooked steel fibers resulted

in a significant improvement in the tensile properties.

7. In mixes containing 2% fibers by volume, the use of 30/50 hooked steel fibers led to a

1- and 28-day flexural strengths about 4 times those given by the polypropylene fiber

mix.

8. Latex significantly improved the load versus deflection response in flexure and the

flexural strength with time (seven and 28 days) of all HESFRC mixes tested. The 28-

day flexural strength increased by 15 to 30% relative to plain FRC.

9. The addition of latex did not enhance the 1-day flexural strength. In fact, in the mix

containing 50/50 steel fibers, a reduction in the 1-day strength was observed when latex

was added.

10. The presence of silica fume in HESFRC mixes was observed to significantly enhance

the flexural response of the 50/50 fiber mix with time. The polypropylene and 30/50 +

50/50 fiber mixes showed an increase in the flexural strength up to day 7, and no

improvement thereafter.

11. In general, the addition of silica fume did not significantly change the 1-day fiexural

response of the 50/50, polypropylene, and hybrid 30/50 + 50/50 mixes (mix series C),

relative to the plain FRC mix.

113

12. No consistent trend was observed for lhe 28-day load-deflection response of mix series

C relative to the plain FRC mixes. Silica fume caused changes of +20%, -15%, and

+3% in the flexural strengths of the 50/50, polypropylene, and 30/50 + 50/50 mixes,

respectively, relative to the plain FRC mixes.

13. From the evaluation of toughness indic:es, it can be generally concluded that the use of

the area under the load-deflection curve of the control mix, as opposed to using the area

under the load-deflection curve up to tSrst cracking, leads to more rational and

consistent results of ductility indices [2,3,4,5, and 7].

14. For practical mixing limitations using steel fibers, a simple rule of thumb is to keep the

reinforcing index Vf 1/4 less than about 1.2, where Vf is the volume fraction of fibers

and 1/4is their aspect ratio (or length divided by diameter). Bending properties should

improve with an increase in the reinforcing index.

7.5 Recommendations

Table 7.2 summarizes the average key results obtained for all 17 HESFRC mixes tested. It

can be generally observed that mixes containing hooked steel fibers can be considered to

satisfy the requirements set forth by the SHRP advisory committee for HESFRC. Mixes

containing 1 or 2% of polypropylene fibers showed substantially lower high early flexural

strengths, as well as toughness indices.

The toughness index of HESFRC mixes should be computed using, as a comparison, a

similar plain concrete mix without fibers. The use of the area under the load-deflection

curve of the same FRC specimen up to first cracking, as suggested in ASTM C 1018,

instead of the control specimen, may lead to notable errors in the estimation of the

toughness index [2,3,4,5, and 7].

7.5.1 Recommendations Based or, Strength Criteria

Based on this experimental investigation, the following recommendations regarding the

flexural strength are proposed (Note that a summary of the average results is given in Table

7.2)

114

1. The optimal mix that gave the highest flexural strength at one day was the mix

containing 2% bv volume of 30/50 hooked steel fibers (A2%S3). Therefore, it is

recommended to use this mix for applications requiring high early tensile (bending)

strength.

2. Next in performance was the hybrid mix containing 2% by volume of 30/50 + 50/50

hooked steel fibers (A2%S3S5).

3. The tensile (bending) properties of the mix containing 1% by volume of 50/50 hooked

steel fibers were also considered very good, as shown in Table 7.2.

4. The use of polypropylene fibers alone in HESFRC mixes is not recommended, since

mixes containing polypropylene fibers showed lower strengths at early ages and post

cracking load-deflection response poorer than equivalent mixes with steel fibers.

However, hybrid mixes with steel and polypropylene fibers fared much better.

5. The use of latex in HESFRC composites is not desirable in applications for which high

early strength is sought. However, the tensile properties of HESFRC composites

containing latex significantly improved with time. Therefore, if the objective is to obtain

high-tensile, long-term strength, latex is recommended for use with mixes containing

1% by volume of 50/50 or 30/50 + 50/50 steel fibers. It should be observed that latex

is generally used to improve other properties, such as bonding between new and old

concrete in repair applications, and to improve durability. These very important

properties were not tested in this investigation. However, it is expected that they would

be improved in HESFRC mixes just as they would for plain concrete mixes.

6. The addition of silica fume does not significantly affect the 1-day flexural properties of

HESFRC composites. However, tensile (bending) properties are improved at later

ages.

7.5.2 Recommendations Based on Energy Absorption (Toughness) Criteria

It can be generally observed from the data that the toughness index decreases with time

(Table 7.2). Considering the toughness indices obtained using the control mix, it seems

very appropriate to set, in addition to the strength limit, a limit for the toughness indices 15,

I10, and I20 for all HESFRC mixes. First-hand recommendations may be as follows: an I5

larger than 5, an I10 larger than 10, and an I20 larger than 15. Since I20 could not be

115

obtained for some of the HESFRC mixes, only 15and I10will be considered. In applying

the above criteria, the following recommendations can be made with regard to the optimal

HESFRC mixes tested at one day:

1. The following mixes can be considered to have equal optimal energy absorption

properties: mix containing 2% of 30/50 fibers (A2%S3), hybrid mix containing 2% of

30/50 + 50/50 fibers (A2%S3S5), and the latex HES mix containing 1% of 50/50

fibers (B 1%S5).

2. Next in performance comes the hybrid latex and silica fume HESFRC mixes containing

1% of 30/50 + 50/50 fibers (B1%S3S5 and C1%$3S5, respectively). These mixes

showed toughness indices 50% lower than the optimal mixes described in 1.

3. All other HESFRC mixes containing either hooked steel fibers or a combination of

polypropylene and hooked steel fibers showed lower, but acceptable, energy

absorption properties.

4. The toughness indices of the HESFRC mixes containing polypropylene fibers were

lower than the limits set forth in this study. Therefore, if the objective is to obtain high

early energy absorption properties, the use of polypropylene fibers alone in HESFRCmixes is not recommended.

116

7.6 References

1. ASTM. Standard Test Method for Flexural Toughness and First-Crack Strength of

Fiber-Reinforced Concrete (Using Beam With Third-Point Loading) ASTM C1018-

89, vol. 04.02.

2. Johnston, C. D. "Definition.and Measurement of Flexural Toughness Parameters for

Fiber Reinforced Concrete" Cement, Concrete, and Aggregates, vol. 4, no. 2(1982),

pp. 53 - 60.

3. Johnston, C. D. "Precision of Flexural Strength and Toughness Parameters for Fiber

Reinforced Concrete" Cement, Concrete, and Aggregates, vol. 4, no. 2(1982), pp.

61 - 67.

4. Johnston, C. D. "Steel Fiber Reinforced and Plain Concrete: Factors Influencing

Flexural Strength Measurement" Journal of the American Concrete Institute, vol.

79, vo. 2(1982), pp. 131 - 138.

5. Johnston, C. D., and R. J. Gray "Flexural Toughness and First-Crack Strength of

Fiber-Reinforced Concrete," paper presented at the 3rd RILEM International

Symposium on Fiber Reinforced Cement Composites, Sheffield, July 1986.

6. Naaman, A. E., and F. M. Alkhairi Flexural and Splitting Tensile Properties of

High Early Strength Fiber Reinforced Concrete SHRP Project C-205, Department

of Civil Engineering, University of Michigan, Report No. UMCE 92-08, April

1992.

7. Ramakrishnan, V., G. Y. Wu, and G. HosaUi "Flexural Behavior And Toughness

of Fiber Reinforced Concretes," paper presented at the Transportation Research

Board 68th Annual Meeting, Washington, D.C., January 1989.

117

8

Splitting Tensile Tests


Tensiletestsweresubdividedinto thr_ major groups(Table 8.1) to parallel the tests

undertakenin compressionand bending [2] : (1) seriesA, consisting of HESFRCmixes

having two volume fractionsof fibers (1 and 2%by volume of concrete), two types of

fibermaterials (hookedsteel fibersandpolypropylene fibers),and for the hooked fibers,

two lengths, 30 and 50 ram; (2) seriesB, consisting of HESFRCmixes containing 1%

fibersby volume and 10%latex solidsby weight of cement; and (3) series C, consisting of

HESFRCmixescontaining 1%fibersbyvolume and 10%microsilica (silica fume) by

weight of cement. Fig. 8.1 shows a flowchart summarizing the test program. Two types

of tests were conductedto studythe tensile propertiesof aUHESFRCmixes: the 1-day

splitting tensile strengthand the 1-daycompressivestrength.Specimen ID notation is

shown in Fig. 8.2.


Fourstandardcylindrical4 x 8 in. test specimenswere prepared to determinethe 1-day

splittingand compressivestrengths. These were obtained directly from the load recorded

by the testing machine. The setup for the splitting tensile tests is shown in Figs. 8.3, and

the setup for the compression tests is described in Fig. 6.4.

Two ofthecylinderswerecappedtwoto three hoursbeforetestingby theuseofasulfur

compound.Thetworemainingcylinderswereusedforthesplittingtensiletests.According

totheASTM C 496-86procedureforthesplittingtensiletest,twopiecesofhardwood

119


Mix Series tFiber Fiber No of Cylinders TestedType Type Volume 4 x 8 in.

Fraction *fspt [ fcVf (%) Test Conducted at (days)

1 1

HES A Conu'ol 0 2 2HES A 30/50 1 2 2IdES A 30/50 2 2 2

A 50/50 1 2 2HES A PP 0.15 2 2HES A PP 1 2 2HES A PP 2 2 2HES A 30/50 + PP 1 2 2HES A 30/50 + PP 2 2 2HES A 30/50 + 50/50 1 2 2HES A 30/50 + 50/50 2 2 2

HES + LA B 50/50 1 2 2HES+ LA B PP 1 2 2HES + LA B 30/50 + 50/50 1 2 2IdES+ SF C 50/50 1 2 2HES + SF C PP 1 2 2

HES + SF C 30/50 + 50/50 1 2 2

Notes: fspt = splitting tensile test; fc = compressivestrengthtest;LA = latex; PP -- polypropylene;SF -- silica fume.

120

• / e_ 0 _.I_

.._ =

121

1D 48 fc 1

- Specimen Number (I, 2, or 3)I


. S = Standard deviation

Y_xat.X

- fc - Compressive and elastic modulus

- fr = Flexural


_ize of Cylinder

48 =4 x8in.

612 = 6x 12 in.

Time of Testim,

- 1D = 1 day

- 3D = 3 days

- 7D = 7 days

-28D = 28 days


122

Fig. 8.3 - Set-up for Splitting Tensile Test

123

PHARDWOOD

Fig. 8.4 . Specimen Positioning for the Splitting Tensile Test

124

measuring 0.25 x 0.75 x 8 in. were placed 180° apart along the longitudinal axis of each

cylinder, as shown in Fig. 8.4. This was done to avoid any stress concentrations that

might result along the line of application of the load. Prior studies on split tensile

properties of FRC were also reviewed for additional information and knowledge [1,3, and

4].

The compressive and splitting tensile tests were performed simultaneously for each series

on a 600-kip-capacity Instron universal hydraulic testing machine. For each test, two

cylinders were te.stedup to failure. Only the nominal compressive and splitting tensile

strengths were recorded.

After completing the compressive tests, the bottom swivel head of the testing machine was

prevented from rotating to facilitate testing for the splitting tensile strength of the two

remaining cylinders. The longitudinal axis of each cylinder was placed at 90° to the loading

direction, with the two pieces of wood directly in contact with the upper and lower parts of

the swivel head. In both tests, the displacement-controlled method was used at a loading

rate of 0.001 in./sec.

The data were recorded by a data acquisition system and were then reduced by the

procedure described in chapter 6.

8.3 Data Analysis and Tests Results

This section discusses the results obtained from the splitting tensile and compressive

strength tests conducted at one day on all 17 HESFRC mixes. Table 8.2 summarizes the

average key results obtained. Tabulated values for each individual specimen can be found

in Table B. 1 of appendix B.

It can be generally observed from Table 8.2 that most mixes containing hooked steel fibers,

particularly with 2% volume content, can be considered to satisfy the requirements set forth

by the SHRP advisory committee for HESFRC. Mixes containing 1 or 2% by volume of

polypropylene fibers showed substantially lower compressive strengths.

Corresponding graphs are presented and commented on next.

125

Table 8.2. Average f'c, fr, and fspt Values for Each Time Series

Mix ID Specmmn :r fc fspt

ID (_si) (ksi) (psi)Control 1D.A 646.88 4.22 407.83Connml 713 A 600.0 ......

_onn_l _D=A 790.31 ......A1%S3 ilD A 937.5 3.26 746.04

,l s3 9os .:- --A1%S3 ?.SDA 937.5 .....A2%S3 ID.A 1545.0 5.83 1024.56_%S3 7D A 1866.56 .....

A2%S3 281_=A 1817.81 .....A.1%S5 1D.A 1451.25 4.79 880.33_,1%S5 7D A 1575.0 .....A1%S5 281_ A t668.75 ....

A. 15%P0.5 !D=A 537.19 4.16 460.36A. 15%P0.5 7DA 787.5 ......A.15%PO.5 28D A 843.8 ......

A 1%P0.5 IDA 64406 4.08 028.66

AI%P0.5 7D.A 701.25 .....

AI%P0.5 28DA 938.44 ......A2%P0.5 ID A 459.38 2.._2 .527.2

A2%P0.5 7D.A 619.69 ......A2%P0.5 28D A 632.81 ......

m

AI%S3S5 1D_A 999.38 4 58 648.56A1%S3S5 7D A 1410.94 .....

A1%S3S5 18I_A 1321.88 .....A2%S3S5 ID.A 1517.81 5.23 1045.45A2%S3S5 ID.A 1757.81 .....

A2%S3S5 ?.SDA 1912.5 ......AI%S3PO.5 liD A 647.81 4.22 ._65.99

AI%S3PO.5 7D_A 770.63 ......

A1%S3P0.5 28D A 909,.$$ .....g2%S 3P0.5 1DA 714.38 3.78 577.93A2%S3PO.5 7D A 934.69 .....

A2%S3P0.5 28D=A 1054.69 .....B1%S5 IDA 1007.81 2.98 666.46Bi%s5 7D A 1378.13 ......

B1%S5 28D A 1921.88 ......BI%PO.5 ID A 57._.63 2.55 328.26

81%P0.5 7D_A 63"7.5 ......

31%P0.5 ?.SD_A 871.88 .....31%S3S5 ID.A 1013.4.4 3.58 507.31B1%S_55 /D.A 1406.25 ......81%S3S5 28D A 1753.13 .....

"1 I

C1%$5 ID_A 1228.13 5.15 859.44

_1%S5 7D A 1449.38 ......C1%$5 ?.SDA 1978.13 .....CI%P0.5 ID.A 553.13 3.7 442.65 •C1%P0.5 7D.A 648.75 .....

C1%P0.5 _D=A 787.5 ......CI%$3S5 ID A 984.38 4.72 802.74

C1%$3S5 ID A 1425.0 ......

C1%$3S5 28D=A 1350.0 .....

126

Fig. 8.5 describes the variation of the MOR, fr, versus the square root of the compressive

strength, f_f-_c• These are the 1-day test results described in chapter 7, Table 7.2. As

observed for plain concrete, a strong correlation exists [3, and 4]. However the best-fit

equation derived from the data is quite different from that used for plain concrete, namely:

fr = -1030. + 30.55 _ (psi) (8.1)

The coefficient of correlation is equal to 0.618, and the conditional standard deviation is

288 psi. The two lines shown in Fig. 8.5 are plus or minus one standard deviation away

from the mean line and bound 68% of the data.

Fig. 8.6 describes the variation of the splitting tensile strength at one day, fspt, versus the

square root of the compressive strength, _ The regression line for the data is given by

the following equation:

fspt = - 611. + 19.73. _ (psi) (8.2)

The conditional standard deviation of the data is 219 psi, and the coefficient of correlation

is 0.646. The two lines plotted in Fig. 8.6 are plus or minus one standard deviation away

from the mean and bound 68% of the data.

Although these two equations for fr and fspt are different from the relations usually

recommended in codes of practice (AASHTO, ACI), it is interesting to note that the ratio

between fr and fspt is about 3/2, as expected.

The results comparing the splitting tensile and compressive strengths for different test

series and different parameters are plotted using bar charts.

• The 50/50 mix of series A containing 1% by volume of fibers showed the highest

splitting tensile strength (fspt) at 1 day, giving 2.16 times the strength of the control

mix. (Note that fspt for the control mix = 407 psi; f'e = 4.22 ksi). Next in performance

was the 30/50 mix, giving a strength 1.84 times that of the control mix. The remaining

mixes of series A gave splitting tensile strengths equal to 1.5 times that of the control

mix (Fig. 8.7).

• Fig. 8.8 shows that the 30/50 and 30/50 + 50/50 mixes containing 2% by volume of

fibers give the highest splitting tensile strengths compared with all other mixes in series

A (1,000 psi compared to 407 psi for the control mix). The mixes containing

polypropylene fibers led to the lowest strengths (450 psi).

127

2000

• Control• A1%S3

O. • A2%S3

b. • A1%S5 ---*"_

"- 1500 • A0.15%P0.5 _e = '

" A1%P0.5= • A2%P05eL • A1%S3S5=3 /a 6/o_" 1000 • A2%S3S5 "/"_ • •m /

+ Al%S3P0.5 "7O • A2%S3P0.5

= • B1%S5 ./. • __2 • Bl%P05 f " ]/T-s 500 •

• B1%S3S5O

o C1°/oS5• C1%P05= C1%$3S5

0 | ! = = -

0 20 40 60 80

f',/_-, (pill o.s )

Fig. 8.5 - Modulus of Rupture fr vs. _cforDifferent Mixes.

-_" 12oo

• Control

=. 1000 • A1°/,,.%3

._- •• A1%S5• A0.15%P0.5

J_., 800 • A1%P0.5 / •/.

=- * A1%S3S5" 600

(0 , A2%S3S5 ///_ 1=.'/+ AltY=S3P0.5

• /= • A2%S3P0.5o_¢ 400' • B1%S5

°I- " B1%P05 •

• B1%S3S5

¢ 200' O C1o/_5,_ • C1%P05m

_. = C1%$3S5

0 20 40 60 80

, (pill o.=)

Fig. 8.6 - Splitting Tensile Strength fspt vs._c for Different Mixes

128

1000

8OO

0

u.¢) e5 m

lk

Fig. 8.7 - Splitting Tensile Strength fspt for Different Mixes, I Day, (Vf=1%)1200

8O0

0

0 _

a,

Fig. 8.8- Splitting Tensile Strength fspt for Different Mixes, 1 Day, (Vf=2%)

129

* Fig. 8.9 compares all three mixes of series B (latex modified) for 1% fiber volume

fraction tested at 1 day. In comparing Figs. 8.7 and 8.9, it can be observed that the

modification of the 50/50, polypropylene, and 30/50 + 50/50 mixes with latex causes

a 30, 50, and 20% reduction in fspt relative to the plain FRC mixes (i.e., series A

mixes).

• Fig. 8.10 shows mix series C containing silica fume. When Fig. 8.10 is compared

with Fig. 8.7, it is observed that silica fume has little effect on changing the splitting

tensile strength when compared with plain FRC.

• Except for the mix containing 1% by volume of 30/50 fibers, Fig. 8.11 clearly shows

that mix series A containing 1% by volume of fibers achieves a compressive strength

in the range of 4 to 5 ksi. The requirement of achieving a minimum compressive

strength of 5 ksi or greater at 24 hours was satisfied for mixes 30/50 and 30/50 +

50/50 containing 2% by volume of fibers. However, mixes containing 2% by volume

of polypropylene fibers or 30/50 + polypropylene fibers did not satisfy this

requirement, as shown in Fig. 8.12.

• Fig. 8.13 shows that the use of latex decreases the 1-day compressive strength of the

50/50, polypropylene, and 30/50 + 50/50 mixes compared with plain FRC (Fig. 8.7),

by 40, 37, and 22%, respectively.

• Figs. 8.14 show that silica fume does not affect the 1-day compressive strength of all

mixes in series C (Fig. 8.7).

8.4 Conclusions

The following conclusions regarding the response of all HESFRC composites subjected

to splitting tensile stresses were arrived at:

1. The observed splitting tensile strength, fspt. of HESFRC mixes showed a good

correlation with the square root of the compressive strength, f'c, as suggested for

plain concrete.

2. Among all mixes of series A containing 1% fibers by volume, the mix with the 50/50

hooked steel fibers led to the highest splitting tensile strength, fspt, about 2.2 times that

130

8OO

6OO

"_es 4OO

,q

0

to

g

a.

Fig. 8.9 - Splitting Tensile Strength fspt for Different Mixes, 1 Day,Latex, (Vf=l%)

W 4_'

0

g.

Fig. 8.10 - Splitting Tensile Strength fspt for Different Mixes, 1 Day,Silica Fume, (Vf-l%)

131

3

_e

2

0

f_ t_ to

_o

ea.

Fig. 8.11 - Compressive Strength f'c for Different Mixes, 1 Day, (Vf=l%)6

0

o -

Fig. 8.12 - Compressive Strength f'c for Different Mixes, 1 Day, (Vf=2%)

132

3

"g 2

o

1

tt_

SL

Fig. 8.13 - Compressive Strength rc for Different Mixes, I Day,Latex, (Vf;1%)

$

5'

4,

"_ 3,

d

2"

1

Ki a

!

g

Fig. 8.14 - Compressive Strength f'c for Different Mixes, 1 Day,Silica Fume, (Vf-l%)

133

of the control mix. Next in performance was the mix with the 30/50 hooked steel

fibers, which had an fsptvalue about twice that of the control mix.

3. For the mixes of series A containing 2% fibers by volume, the mixes with the 30/50

and 30/50 + 50/50 hooked steel fibers gave the highest values for fsptamong all mixes;about 2.5 times that of the control mix.

4. The addition of latex led to a decrease of about 25% in the 1-day splitting tensile

strengthfor the mixes with 50/50 and 30/50 + 50/50 fibers and almost 50% in the mix

containingpolypropylene fibers, when compared with the mix without latex. In the

case of polypropylene fibers, the strength was even lower than that of plain concretewithout fibers or latex.

5. The addition of silica fume did not lead to any consistent trend for the mixes of series C

relative to the plain FRC mixes of series A. However, increases of 115 and 100% in

the 1-day splitting tensile strength were observed for the mixes with the 50/50 and

30/50 + 50/50 fibers, respectively, relative to the control plain concrete mix. The mix

with polypropylene fibers and silica fume fared less well than the mix without silicafume.

8.5 Recommendations

Based on this experimental investigation, the followingrecommendationsregardingthe

splittingtensile and compressive strengths areproposed. These recommendationsare

strictlybased on strength criteria. Note that a summary of the results is given in Table

8.2).

1. The optimal mix, which gave the highest splitting tensile and compressivestrengths at I

day, was the mix containing 2% by volume of 30/50 hooked steel fibers (A2%S3).

Therefore, this mix is recommended foxapplicationsrequiting high early tensile

strength.



3. The tensile properties of the mix containing 1% by volume of 50/50 hooked steel fibers

were also considered very good, as shown in Table 8.2.

134

4. The useofpolypropylcncfibersaloneinFIESFRCmixesisnotrecommended,since

mixescontainingpolypropylcncfibersshowedlowerstrengthsatearlyages.However,

hybridmixeswithsteelandpolypropylcnefibersfaredmuch better.



containinglatexsignificantlyimprovedwithtime.Therefore,fftheobjectiveistoobtain

high-tensile,long-termstrength,latexisrecommendedforusewithmixescontaining

i% byvolumeof50/50or30/50+ 50/50steelfibers.Itshouldbeobservedthatlatex

isgenerallyusedtoimproveotherproperties,suchasbondingbetweennew andold

concreteinrepairapplications,anddurability.Theseveryimportantpropertieswere

nottestedinthisinvestigation.However,itisexpectedthattheywouldbeimprovedin

HESFRC mixesjustastheywouldforplainconcretemixes.

6. Theadditionofsilicafumedoesnotsignificantlyaffectthel-daytensilepropertiesof

HESFRC composites.However,tensileproperdcsarcimprovedatlaterages.

135

8.6 References

1. ACI Committee 544. Measurement of Properties of Fiber Reinforced Concrete. ACI

Material Journal, 85, no. 6, Nov - l')ec 1988, pp 583 - 593.

2. Naaman, A. E., and F. M. Alkhairi Flexural and Splitting Tensile Properties of High

Early Strength Fiber Reinforced Concrete Depaiiaiient of Civil Engineering,

University of Michigan. Report No. UMCE 92-08. April 1992.

3. Nanni, A. "Splitting-Tension Test for Fiber Reinforced Concrete" ACI Material

Journal, 85, no. 4, July - Aug 1988, pp 229 - 233.

4. Potrzebowski, J. "The Splitting Test Applied to Steel Fibre Reinforced Concrete"

International Journal of Cement Composites and Lightweight Concrete, 5, no. I,

(Feb 1983), pp 49 - 53.

136

9

Fatigue Tests


This part of the experimental program addresses the flexural fatigue testing of HESFRC beam

specimens under different load ranges. Because fatigue testing is extremely time consuming, it

was decided to limit the fatigue-testing program to only two mixes that gave best properties in

static compression, bending, and split tension (chapters 6, 7, and 8) and satisfied as well the

criterion for HESFRC set forth by the project advisory group.

The two mixes selected are described in chapter 4, A2%S3 and the A2%S3S5; that is, they are

made with concrete mix A, and contain 2% by volume of hooked steel fibers. The first mix

used the Dramix 30/50 (length = 30 mm; diameter - 0.5 mm; aspect ratio = 60) fibers, wheras

the second mix (hybrid mix) used an equal amount of Dramix 30/50 and Dramix 50/50 (length

= 50 mm ; diameter = 0.5 mm; aspect ratio = 100) fibers.

A total of 24 flexural specimens (numbered 1 to 24 for easy identification) were tested. Ten

control specimens were tested under static flexuml loading, and 14 specimens were tested

under fatigue loading.

For each mix, three different target load ranges were applied: 10 - 70%, 10 - 80%, and 10 -

90% of the ultimate flexural capacity, as obtained from the corresponding control static test.

The experimental program is described in Fig. 9.1.

137

I ExperimentalProgram I

+J HES- High EarlyStrength I

Volume Fraction =2%

+Hooked Steel Fibers Hooked Steel Fibers

I I

II ,°,.-.°,_I

Fig. 9.1 - Experimental Program for Fiexural Fatigue

138

The specimens were 16 in. long with a square cross section of 4 x 4 in. Third-point loading at

a clear span of 12 in. according to ASTM C 1018, was used, in a manner similar to that

described in Chapter 7.


All flexural tests were performed in a 22-Kip capacity MTS hydraulic testing machine, Model

810 (Fig. 9.2). Three types of measurements were recorded for each beam: (1) the load from

the load cell of the testing machine, (2) the vertical deflection at the third points, and (3) the

bottom tensile elongation measured over a 4 in. gauge length between the load application

points. The vertical deflection was measured by two LVDT s placed at the third points on

opposite sides of the test beam. The bottom tensile elongation (also described here as strain

capacity) was obtained by one LVDT placed under the specimen along its plane of symmetry

and attached to a special aluminum frame, which in turn was fixed to the specimen third points

(Fig. 9.3). All measurements were recorded via a data acquisition system controlled by a

computer.

Before fatigue testing, all specimens were subjected to a nondestructive test to determine their

dynamic elastic modulus. The resonant frequency method (ASTM C 215-60) was used. The

prismatic specimens were subjected to flexural vibration, and the resonance frequencies of the

fundamental mode were recorded. These values were then used to determine the dynamic

modulus according to the expression provided in the standard. Values of dynamic modulus for

all specimens tested are summarized in Table 9.1. It was assumed that such values may

provide an additional measure of the prediction of the strength of the fatigue specimen, and

thus a possible correction to the cyclic load range applied.

The control static flexural tests were performed under displacement control. Measurements of

the load, deflections at the third points, and tensile elongation at the bottom fiber were

recorded, and the ultimate flexural capacity was obtained.

The fatigue tests were performed under load control. Each specimen was first subjected to three

slow cycles between the minimum and maximum load, to record the initial hysteresis loops

and stabilize the specimen. Then the specimen was subjected to a sinusoidal wave cyclic

fatigue loading with a frequency that, depending on the load range and expected fatigue life

from prior studies [1,2, and 3], varied between 1 and 5 hertz. The fatigue test was interrupted

periodically at a selected number of cycles to record, at a slow rate, an entire hysteresis loop

139

;,

Fig. 9.2 - Testing Machine Used in Flexural Fatigue Tests

140

Fig. 9.3 - Instrumentation and Test Set-up for Flexural Fatigue Tests

141

C

[.., [., r_ a,a, ELI.....n

m

_,_ • ,,._ t,,q t,_ .,_1- tr_ ,_ t,._ _ _.,_ _ _"_ t"q ¢_ "_ _r_ '_l_t'_ _ _'_ _ '_''_ ¢'q

142

between the minimum and the maximum load. The hysteresis loops were obtained for the load

versus third-point deflection and the load versus tensile elongation (or equivalently the strain

capacity) at the bottom fiber.

It should be noted that for the load ranges of 10 to 80% and 10 to 90%, two to three visible

cracks in the constant moment region were observed during the initial three static cycles. For

the specimens with the 10% to 70% loading range, no visible cracks could be detected with the

naked eye during the first three cycles. However, all specimens showed visible cracks (two to

three, not all the way through from both sides) during the first few thousand cycles

(ascertained during the recording of the hysteretic response with a 5x hand-held magnifier).

Since the specimens at the 10 to 70% loading range all showed fatigue life ranging from 105 to

more than 5 x 106 cycles, it can be stated that all specimens tested in this program were

effectively precracked before cyclic loading. This is an essential characteristic of the tests

undertaken here, when compared with previous studies on fiber-reinforced concrete.

The specimens were subjected to a constant load range fatigue loading until failure or 5 million

cycles, whichever occurred first. The two specimens that survived 5 million cycles were then

subjected to a static bending test up to failure.

Photographs of typical specimens that failed under fatigue loading are shown in Figs. 9.4 and

9.5 for mixes A2%S3 and A2%S3S5, respectively. As observed for all specimens, one major

crack (out of two to three visible ones) propagated in the constant moment region until final

failure of the specimen occurred.

9.3 Data Analysis and Test Results

The data recorded from the experiments were plotted in several ways, which include load

versus deflection curves and load versus strain capacity curves under both static or cyclic

loading and increases in deflection or strain capacity with the number of cycles of loading.

Some of these graphs are shown in the following sections, and the remainder can be found in

appendix C.

Table 9.1 summarizes the results of MOR obtained from the static load-deflection tests, and the

dynamic modulus obtainedfrom the dynamic modulus tests. The static MOR was used as a

reference value, based on which the load range for the fatigue test was determined for each

series. Table 9.2 summarizes, for each fatigue specimen tested, information on the load range,

143

Fig. 9.4 - Specimen #10 After Fatigue Failure, Mix A2%S3, Load Range 10%-70%

Fig. 9.5 - Specimen #15 After Fatigue Failure, Mix A2%S3S5, Load Range 10%-90%

144

°_

L_

•It. ,K-

o

ooo_ooo I '_ _ °° °°'_ _ _'_ _ _ _1__ _

#, _ eee _iT!eeeeeeee_

_ _ °O_ • eq _ _r_ o_ o_ _ _ _ _ _" °° _ _'_ _

145

number of cycles to failure, and, for the two specimens that survived 5 million cycles, the

MOR obtained from a static test to failure after fatigue loading.

The main highlights of the results are described next.

9.3.1 Dynamic Modulus of Elasticity

The main reason for running the dynamic modulus tests was to provide some correlation

between the MOR and the dynamic modulus, thus allowing for an additional method to predict

the MOR of the fatigue specimen: This should provide a means to introduce a possible

correction in the cyclic load range applied or to better explain certain results.

A comparison between the flexural strength (MOR) and the dynamic modulus data was carried

out for the specimens tested under static loading. The trend observed is illustrated in Fig. 9.6.

A power curve was fitted, leading to the following relation between the dynamic modulus,

Edyn, and the MOR, fr:

Edyn = 874,000. fr0.228 (psi) (9.1)

with a coefficient of correlation of 0.85. The above relationship was tried, as a second

alternative, to adjust stress ranges in the fatigue tests; however, the corresponding S-N diagram

showed a poorer correlation than obtained with the target stress ranges (first alternative):

Consequently, the second alternative was :notpursued further.

9.3.2 Fatigue Life and Endurance Limit

The fatigue life of a specimen is defined as the number of cycles to failure at the given loading

range. A large scatter is usually observed in fatigue life, even in the most carefully planned

tests. This is because a small error in the estimate of the ultimate strength induces an error in

the load range, which in turn can have an enormous effect on the number of cycles to failure.

Because of the limited scope of this study, only two to three specimens were tested under every

loading range. Results are presented in Table 9.2. In the table, the target load ranges based on

the flexural strength of the control test are shown in percent.

146

It can be observed from Table 9.2 that the specimens subjected to a loading range between

10 and 90% of the ultimate strength had a very low fatigue life. A major crack was always

observed in the first cycle, and with further cycling, it would propagate rapidly towards the

compression zone of the specimen, leading to its final collapse. The two specimens of

series A2%S3 sustained 9 and 23 cycles, respectively, and the two specimens of series

A2%S3S5 sustained only 2 and 4 cycles.

The specimens subjected to the 10 to 80% loading range sustained the following numbers

of cycles to failure: 3,679 and 3,900 cycles for the specimens of series A2%S3, and 8,964

and 15,000 cycles for the specimens of series A2%S3S5. Thus, on the average, series

A2%S3S5 sustained at least three times the number of cycles to failure resisted by series

A2%S3. The difference between the two may be attributed to the presence of longer fibers

in series A2%S3S5 (that is 50 mm versus 30 ram). However, the difference between the

two series may also seem insignificant when the data are plotted on a log scale.

For the loading range of 10 to 70%, three specimens were tested for each series. Five out of

the 6 specimens sustained more than 1.9 x 106 cycles, and one specimen of each series had

not failed after 5 million cycles. For these specimens, cyclic loading was stopped, and a

monotonic loading test to failure was carded out. The corresponding MOR was larger than

that of the control specimen, confirming a previously noted result that prior cycling may

lead to an improvement in strength [1,2, and 3]. The relatively large variability observed in

the tests at this range of loading indicates the endurance limit of the material is probably

being approached.

The maximum load as a percentage of the ultimate load is plotted versus the logarithm of

the number of cycles to failure in Fig 9.7 for all specimens, and a least-square-fit line is

derived. It can be observed that an endurance of about 68% of ultimate load may be

considered for 5 x 106 cycles.

9.3.3. Fatigue Life and Endurance Limit: Comparison with Other

Investigations

An extensive investigation on the fatigue life of FRC was carded out by Ramakrishnan et al. [1

to 3]. Several particular aspects of their investigation are pointed out next because of

differences with the present study: (1) the load ranges selected for the study were determined

with respect to the reference plain concrete mix without fibers; (2) the frequency of cyclic

147

5.5 1 06 .... E ................ i ....

C

>" 06 ..................2................................................• ........-....................•_ 5.1 1 .................

LLi ; • . • i ;

N 4.7 1 06 ...................................................

"0 ,/_ Edyn I _ D.2280 873890 _ fr

._o 06 ............................oo.....i :E 4.2 1 ....................'...........................................................:

C :

t_ 3.8 106 .................. _'''' ! ....

500.00 1500.00 2500.00 3500.00

Modulus of Rupture f (psi)r

Fig. 9.6 - Modulus of Rupture versus Dynamic Modulus

1 0 0 % ........1 ....... ! ........y ............... 'T ........T ........ l .......Minimum Loadi at10% of: Ultimate

m .-.. 90 % _.":'.'.'.'.'.'.'_-e................................................................... �.............................

"0 "_ = 93. -- .68 I g (N)

E o 70%

60% ..........................................................._..............i...............-...............,.............Specimens that

" " i

!didn'ti fall........I ........1 ....... ; ........I ........1 ....... I ,

50% ........ ' '"'"1 00 1 02 1 04 1 06 1 08

Cycles to Failure Nf

Fig. 9.7 - Number of Cycles to Failure versus Maximum Applied Load

148

loading was 20 hertz, a value considered too high to maintain an accurate load range and to

minimize the effects of inertia; and (3) the specimens were not precracked.

Ramakrishnan et al. concluded that for specimens reinforced with hooked-end steel fibers at

volume fractions of 0.5 and 0.8% with aspect ratios of 75 and 100, the maximum absolute

fatigue load under which the specimens could withstand 2 million cycles without failure was

2.0 to 2.5 times that of corresponding specimens with a plain mix with no fibers. In reference,

similar results were obtained for the absolute value of the fatigue load in specimens reinforced

with hooked-erA fibers with an aspect ratio of 100 at a volume fraction of 1%. Such results

are predictable, since the reference mix was taken as the concrete without fibers. In many

cases, the presence of fibers leads to a significant increase in the MOR. Indeed, referring for

instance to Table 7.2, it can be observed that the average MOR of the control mix without

fibers is 690 psi. On the other hand, the MOR of the same mix with 2% fibers (Table 9.1)

exceeds 1,265 psi in all cases. In the present investigation, the reference MOR (or flexural

strength) for adjusting fatigue load ranges for a given specimen was taken as that of the sister

specimen of the same mix with fibers tested under static loading.

9.3.4 Hysteretic Load versus Deflection Response

Hysteresis loops were recorded at various stages of the fatigue life of each specimens. Typical

examples are shown in Figs. 9.8 and 9.9, and additional information can be found in appendix

C.

The area enclosed by the load versus deflection hysteresis loop describes the amount of damage

done to the specimen during any recorded cycle. The hysteresis 10op allows us to extract the

values of deflections at Pmin and Pmaxand the permanent (non recoverable) deflection at any

cycle. Furthermore, the variation of the deflection between the minimum and maximum loads

gives a good indication of the loss of stiffness of the specimen due to fatigue loading.

In the specimens subjected to the 10 to 90% loading range (Figs. 9.8 and 9.11), the material

degradation is clearly illustrated by the large area enclosed by every loop and the resulting small

number of cycles to failure.

In the specimens subjected to the 10 to 80% and 10 to 70% loading ranges, the hysteresis

loops had a larger area at the initial cycles, followed by a stabilization period during which the

loops remained almost constant; then, closer to the fatigue life of the specimen, the area

149

12.00 .... I ........ ' ' ' I ....Spec #16 iA2%S3S5

10.00 ..............................................................................................i.......................- Fatigue LoaOing

: Range: i 10%-_cYC' les

) iiiiiiii!.......................g ..oo -.... i600

O4OOoo....................o oo _._l_,_ i _ _ .

0.000 0.010 0.020 0.030 0.040 0.050

Deflection (in)

Fig. 9.8 - Load versus Deflection Hysteretic Response of Specimen #16 underFatigue Loading

14.00 . , , , , , , j , , , _ , , ,Spec #20

1 2.0 0 -A2.%S3S5 .................... ! .......... _.......................Fatigue Loading

10. 0 0 _.Range: ......:1"0"%'80"?/'_"0Dff"8;;81_'_.......;...........................

"-" 8.00 ............... - ...........................

oooo..........Z......:II ........I

2.004.00 __ __ :::i'_"_'_'_"-. ....• 6000 cyclps0.00 , , , I , , , . , , , , , ,

0.000 0.013 0.025 0.038 0.050

Deflection (in)

Fig. 9.9 - Load versus Deflection Hysteretic Response of Specimen #20 underFatigue Loading

150

enclosed by the hysteresis loop increased again. This is clearly shown in Fig. 9.10 and 9.11.

Also observed in these figures is the relatively large permanent deflection developed with

cyclic loading.

Other important results of the fatigue tests are the increase in the p_mianent deflection at the

minimum and maximum applied load levels (Pminand Pmax) and the increase in the difference

of deflection (AS) between the minimum and maximum loads with the number of loading

cycles. Typical results are illustrated in Figs 9.12 to 9.13, and additional figures can be found

in appendix C.

The two specimens that did not fail under fatigue loading, specimens 9 (A2%S3) and 17

(A2%S3S5), showed different behaviors. Specimen 9 showed a period of constant permanent

deformations until about 2 million cycles, after which there was a substantial increase in the

permanent deformation until about 3 million cycles, followed by another period of constant

increase until the fatigue tests were interrupted at 5.276 million cycles. Specimen 17 (Fig.

9.13) showed a period of constant permanent deformation until the interruption of the fatigue

test at 5 million cycles. The post fatigue static load versus deflection curves for these two

specimens were similar to the static bending tests described in chapter 7 (Fig. 9.14). As

observed in previous investigations [1], the MOR obtained after fatigue is higher than that

before fatigue loading.

9.3.5 Load versus Tensile Strain Capacity

The average tensile strain in the constant moment region is related to the average crack width

observed. This is because the elastic tensile strains, being on the order of 2 x 104, can be

neglected. Most specimens had one to three visible cracks along the constant moment region.

Typical variations of the average tensile strain in the constant moment region at the minimum

and maximum applied load levels (Pminand Pmax)and the tensile strain difference (Ae)

between the minimum and maximum loads are plotted against the number of cycles in Figs.

9.15 and 9.16 for some of the specimens that failed under fatigue loading. A trend similar to

what was observed for deflection is noted; namely, a larger rate of increase in the early cycles,

followed by a period of stabilization with a constant rate of increase up to about 90 to 95% of

fatigue life, then again a higher rate of increase leading to failure.

151

12.00 .... i , _-- ..... z .... ....

; Spec #18 t.................2 A2%S3S5

1o.oo '!.......................................i__;ig_;£o;_ing........."3000 cyc!es Range: 10..=/=-70%

="8.oo -_..._y._o.._----t-1-11.............i................._1---"'-

o i"J 4.00 ............

2.00 ! _]Sf = ;9_09-42cycles [ r0.00 ................

0.000 0.010 0.020 0.030 0.040 0.050

Deflection (in)

Fig. 9.10 - Load versus Deflection Hysteretie Response of Specimen #18 underFatigue Loading

0.050 ' ' ' i ............Spec #21A2%S3S5

... 0.040 -Fatlgu_toacllng ...................i......................;.......................

._ Range:_ 10% to 80% i :

° o ......................................9

m _8

0 0.010 ..........-' -- .......T "_ ? ........................: iPmin,' • !lNf= 8964J

0.000 ,,, I, _, i,,, i,, _ , , ,0 2000 4000 6000 8000 10000

Number of Cycles

Fig. 9.11 - Variation of Deflection versus Number of Cycles for Specimen #21

152

• , i _ 1 1 1 i - 1 1 _ i i | 1 i

0 050 I- Spec #18

A2%S3S5 T.... O. 040 -"F_i'ti_'ii6"E'6&i_li_'iij........... i......................i...............¢= Range:i lO% to_70% i i /

- i i I..--t,C;.030 .........................................................................................

.o_ !o O 020 ...................... _"-':........=": :

,.--'=®" _.a O.OLO

A6 IINf = 19109420.000''' ' ' ' ' ' ' ' ' " ' ' ' ' ' '

0 800000 1600000

Number of Cycles


0,080 _ .... i ................Spec _17

O. 070 F-_,2%"S'._"_'5...............-:..................._.....................[.......................

o.o6o _F-.-._a-t..!g.u,,._..--.L....°.._-_!.ng.....................i.......................i........................-: _Targetl Range:i 10%-70..=/o

0.050

.2 0,040dineOm 0.030i

0.020

0.010

0.0000 2000000 4000000

Number of Cycles


153

20.00 .... I ........ I ........Spec #17A2%S31S5 i

16.oo -Zi-/,;_-'_'_x-{i_e-(_;_;ie-_-ai-1-6;_'."_"i_-;)_.....................

_,,12.00 ....

"omO 8.00 --..I

,ooFl0.00

0.00 0.10 0.20 0.30 0.40 0.50

Deflection (in)

Fig. 9.14 - Load Versus Deflection Response after Fatigue Loading for

Specimen # 17

0.020 , . , j ............

Spe¢ :#21A2%S2S3

0.01 6 --FiiJig__"E_ii_ ........................................................................i- Range,, 10% t(_ 80%

¢: 0 012 ....................................................................................................................

:._-ooo_...................-......................._........................i-,_-__..............

0.004 I_1 ...........0.000 : ' ' _ I , , , I , , , ] , , , I , , ,

0 2000 4000 6000 8000 I 0000

Number of Cycles

Fig.9.15- Variation of Strain versus Number of Cyclesfor Specimen #21

154

0.010 ' ' ' i ' ' ' I ............

Spec" #10A2%S3

0.0 0 8 --F_rti__E6_i_Iifi_..................._................................

.¢ Range: 10% to

.E o.oo6 ...........................................................................................

_:ooo,° ......................_E0.002 ..........

0.000 ,,, I,,, I,,, I,,, _ ,,, ] , , ,0 40000 80000 120000

Number of Cycles

Fig. 9.16 - Variation of Strain versus Number of Cycles for Specimen #10

155

9.4 Conclusions

1. Specimens reinforced with hooked-end steel fibers at volume fractions of 2% showed

average fatigue lives of the order of 10 c_,cles for loads ranging between 10 and 90% of

their static strength, 8,000 cycles for loads ranging between 10 and 80%, and more than

2.7 x 106 cycles for loads ranging between 10 and 70%. These values hold, assuming the

specimens are cracked. Substantially lar_er values can be achieved with uncracked

specimens.

2. From the limited number of tests undertaken in this study, the derived S-N curve in

bending of HESFRC with 2% by volume of hooked steel fibers is given by

S = 93 - 3.68 log(N 0 (9.2)

where S is the maximum cyclic load as a percentage of the static MOR, and Nf is the

number of cycles to failure. The coefficient of correlation for the above equation is 0.976.

It can be inferred that the fatigue life of HESFRC containing 2% by volume of hooked steel

fibers is on the order of 68% of their static flexural strength for 5 million cycles, 67% for

10 million cycles, and 65% for 50 million cycles. For all practical purposes, a stress rangeof 65% can be taken as the endurance lirrdt.

3. Mixes A2%S3 and A2%S3S5, reinforcext with 2% hooked-end steel fibers, with aspect

ratios of 60 and a mix of 60 and 100, respectively, showed similar behavior under fatigue

loading.

4. HESFRC mixes containing 2% by volume of hooked steel fibers can sustain substantially

higher fatigue stresses than plain concrete without fibers.

9.5 Recommendations

For HESFRC mixes with 2% hooked steel fibers by volume, a safe endurance limit for cyclic

fatigue loading in bending can be taken at about 65% of the static ultimate strength (or

equivalently the MOR) obtained from a control specimen with fibers. This result should be

valid even if the beam is cracked at maximum load.

156

9.6 References

1. Ramakrishnan, V., G. Oberling, and P. TatnaU "Flexural Fatigue Strength of Steel FiberReinforced Concrete. Fiber Reinforced Concrete: Properties and Applications. SP 105-13. American Concrete Institute, Detroit (1987): 225 - 245.

2. Ramakrishnan, V., G. Y. Wu, and G. Hosalli "Flexural Fatigue Strength, EnduranceLimit, and Impact Strength of Fiber Reinforced Concretes" paper presented at the 68thAnnual Meeting of the Transportation Research Board,Washington, D.C., January 1989.

3. Ramakrishnan, V., and B. J. Lokvik "Flexural Fatigue Strength of Fiber ReinforcedConcretes" High Performance Fiber Reinforced Cement Composites, RILEMProceedings 15, H.W. Reinhardt and A.E. Naaman, Chapman and Hall, London, 1992.

157

10

Summary and Recommendations

The Executive Summary at the beginning of this volume provides some general

recommendations relevant to all mechanical properties of HESFRC mixes tested in this

investigation. Specific conclusions related to the compression, bending, tension, and

fatigue properties of HESFRC mixes can be found at the end of chapters 6, 7, 8 and 9,

respectively. Recommendations related to the compression, bending, tensile, and fatigue

properties are given in this chapter. The conclusions and recommendations of this study

relate to hooked steel fibers and monofilament polypropylene fibers and do not necessarily

apply to other types of fibers.

10.1 Compression Tests

An extensive experimental investigation was carried out on the compressive properties of

HESFRC. Tests on the mechanical properties included compressive strength and elastic

modulus with time. In all, 16 different mixes were investigated. The database gathered

comprised (1) the stress versus strain response in compression of each time series and its

representative average; (2) a comparison of various time series taken from the same mix;

(3) a comparative evaluation of different mixes at 1 and 28 days; and (4) a comparison of

the compressive strength and elastic modulus of various mixes with time.

The following recommendations were arrived at

1. The use of 1 to 2% by volume of 30/50 hooked steel fibers gave optimum composite

properties in the fresh and hardened state. It caused a significant increase in the

compressive strength, elastic modulus, and ductility when compared with all other

HESFRC mixes.

159

2. Next in performance was the use of 1% by volume of either 30/50 + 50/50 steel fibers

or 50/50 steel fibers. Both mixes performed very similarly in terms of compressive

strength, elastic modulus, and stress-strain response. The 1-day compressive strength

of these mixes exceeded the required rrtmimurn of 5 ksi.

3. Mixes containing 1 to 2% by volume of polypropylene fibers showed deterioration in

the compressive stress-strain response when compared with the control mix. Therefore,

the use of polypropylene fibers alone to improve strength and elastic modulus is not

desirable. However, the use of 1% by volume of polypropylene fibers in conjunction

with 1% by volume of 30/50 hooked steel fibers in the same HESFRC mix led to a

slight improvement in the compressive stress-strain properties.

4. Although latex improved the workability of HESFRC mixes, it is not desirable to use

latex with HESFRC mixes for the purpose of improving early age properties.

However, latex did improve the long-term compressive stress-strain response ofHESFRC mixes.

5. Silica fume had no significant effect on the compressive strength at I day. However, it

significantly increased the compressive strength of HESFRC mixes at later ages.

10.2 Bending Tests

The properties of HESFRC subjected to static flexural loading were studied. The

experimental program included flexural testing at 1, 7, and 28 days. In all, 17 different

mixes were investigated. The data gathered included (1) the load vs. deflection and load vs.

strain capacity response in flexure of each time series and its representative average; (2) a

comparison of various time series taken from the same mix; (3) a comparative evaluation of

different mixes at 1 and 28 days; and (4) a comparison of the toughness indices versus time

for various mixes using the ASTM C 1018 approach (which uses the first cracking load)

and the control test approach.

The following recommendations regarding the response of all HESFRC composites inflexure were arrived at:

160

10.2.1 Recommendations Based on Strength Criteria

1. The optimum mix that gave the highest flexural strength at 1 day was the mix

containing 2% by volume of 30/50 hooked steel fibers (A2%S3). Therefore, this mix is

recommended for applications requiring high early tensile strength.



3. The bending properties of the mix containing 1% by volume of 50/50 hooked steel

fibers were also considered very good.

4. The use of polypropylene fibers alone in HESFRC mixes is not considered very

effective, since mixes containing polypropylene fibers showed lower strengths at early

ages and poorer post cracking load-deflection response than mixes containing equal

volumes of hooked steel fibers. However, hybrid mixes with steel and polypropylene

fibers fared much better.



containing latex significantly improved with time. Therefore, ff the objective is to obtain




concrete in repair applications, and durability. These very important properties were

not tested in this investigation. However, it is expected that they would be improved in

HESFRC mixes just as they would for plain concrete mixes.

6. The addition of silica fume does not significantly affect the 1-day flexural properties of

HESFRC composites. However, tensile properties are improved at later ages.

10.2.2 Recommendations Based on Energy Absorption (Toughness)Criteria

1. The following mixes can be considered to have equal optimal energy absorption

properties: mix containing 2% of 30/50 fibers (A2%S3), hybrid mix containing 2% of

161

30/50 + 50/50 fibers (A2%S3S5), and the latex HES mix containing 1% of 50/50

fibers (B 1%S5).

2. Next in performance come the hybrid latex and silica fume HESFRC mixes containing

1% of 30/50 + 50/50 fibers (B1%S3S5 and C1%$3S5, respectively).

3. All other HESFRC mixes containing either hooked steel fibers or a combination of

polypropylene and hooked steel fibers showed lower, but acceptable, energy

absorption properties.

4. The toughness indices of HESFRC mixes containing polypropylene fibers were

substantially lower than those achieved 'with equal volumes of hooked steel fibers;

however with 1 and 2% fibers by volurne, toughness indices I5 and I10 were within

the limit recommended (targeted) in this study for HESFRC (i.e., 15 > 5 and I10 > 10).

If the objective is to obtain high toughness, impact or energy absorption properties, the

use of steel fibers in HESFRC mixes is preferred over polypropylene fibers.

10.3 Splitting Tensile Tests

This section summarizes the main results of this part of the experimental investigation,

which included splitting tensile and compressive tests at 1 day. In all, 17 different mixes

were investigated. The following recommendations regarding the splitting tensile and

compressive strengths are proposed:

1. The optimal mix that gave the highest spatting tensile and compressive strengths at 1

day was the mix containing 2% by volume of 30/50 hooked steel fibers (A2%S3).

Therefore, this mix is recommendedfor applications requiring high early tensile

strength.



3. The tensile properties of the mix containing 1% by volume of 50/50 hooked steel fibers

were also considered very good.

4. The use of polypropylene fibers alone in HESFRC mixes produced lower tensile

strengths than mixes with equal volume of hooked steel fibers, but higher strengths

162

thanthecontrolmix withoutfibers.Moreover,hybridmixeswithsteeland

polypropylenefibersfaredmuch better.

5. The useoflatexinHESFRC compositesisnotdesirableinapplicationsforwhichhigh

carlystrengthissoughtHowever,thetensilepropertiesofHESFRC composites

containing latex significantly improved with time. Therefore, ff the objective is to obtain




concrete in repair applications, and durability. These very important properties were

not tested in this investigation. However, it is expected that they would be improved in

HESFRC mixes just as they would for plain concrete mixes.

6. The addition of silica fume does not significantly affect the 1-day tensile properties of

HESFRC composites. However, tensile properties are improved at later ages.

10.4 Fatigue Tests

Specimens reinforced with hooked steel fibers atvolume fractions of 2% showed average

fatigue lives on the order of 10 cycles for loads ranging between 10 and 90% of their static

strength, 8,000 cycles for loads ranging between 10 and 80%, and more than 2.7 x 106

cycles for loads ranging between 10 and 70%. These values hold if the specimens are

cracked. Substantially larger values can be achieved with uncracked specimens.

The endurance limit of HESFRC containing 2% by volume of hooked steel fibers is on the

orderof 65% of their static flexural strength.

10.5 Recommendations for Future Research

Theresultsachievedinthisinvestigationcanbeconsideredageneralguideonthe

feasibilityofproducingHESFRC with(1)atargetcompressivestrengthof5ksi(35MPa)

at24hours;(2)apostcrackingstrengthinbending(modulusorrupture)largerthanthe

crackingstrength;and(3)toughnessindicesI5and110respectively,largerthan5 and10.

Whcraslocalconditionsandmaterialsusedfortheconcretematrixwillleadtosmall

anticipatedvariations,theuseoffibersdifferentfromthoseselectedinthisstudymay lead

163

to substantial differences in results. It is thus recommended that an evaluation of the use of

different types of fibers in HESFRC mixes _ undertaken and some correlation between

results using different fibers be established. Similarly, there is need to establish a cost-

effectiveness evaluation of the benefits of using fibers in transportation structures.

VES concrete was covered in volume 3. However, no attempt was made to explore VES

concrete with fibers. If the applications of VES concrete are for rapid repair, such as for

bridge decks and pot holes, then the addition of fibers can only improve the properties

needed for such applications. It is thus recommended that the properties of VES fiber

reinforced concrete be studied in a manner similar to that undertaken for HESFRC.

The selected fatigue tests undertakenin this study were for mixes containing 2% by volume

of hooked steel fibers. A fatigue limit of 65% of ultimate was observed, even in pre-

cracked specimens. There is a need to check whether a smaller volume fraction of hooked

steel fibers (say, 1 or 1.5%) in HESFRC mixes, or the use of other types of fibers willlead to a similar result.

Although, as demonstrated in this study, many mechanical properties can be substantially

improved by adding fibers to concrete, the most dramatic improvement is observed in the

toughness or energy absorption capacity of the composite. This property is particularly

useful in pavements, overlays, and runways applications for which impact and fatigue are

critical. A life-cycle cost evaluation of the benefits of adding fibers to such structures isrecommended.

164

Bibliography

General Background History Books

ACI Committee 544. State of the Art Report on Fiber Reinforced Concrete(AC1544. IR-82). Concrete International: Design and Construction, May 1982,pp. 9 - 30. Also published separately by American Concrete Institute, 1982,and Manual of Concrete Practice part 5.

ACI Committee 544. Design Considerations for Steel Fiber ReinforcedConcrete. ACI Structural Journal, voi.85, no. 5 (September - October 1988):563 - 580.

ACI Committee 544. Guide for Specifying, Proportioning, Mixing, Placing,and Finishing Steel Fiber Reinforced Concrete. ACI Materials Journal, 90, no.1 (January- February 1993): 94- 101.

Alkhairi, F.M., and A.E. Naaman. An Annotated Bibliography on HighStrength Fiber Reinforced Concrete. Department of Civil Engineering,University of Michigan, Report No. UMCE 91-08, December 1991.

Balaguru, P.N., and S.P.Shah. Fiber Reinforced Cement Composites. NewYork, McGraw Hill: 1992.

Hannant, D.J. Fiber Cements and Fiber Concretes. Chichester, England, Wiley& Sons: 1984.

Naaman, A. E. "Fiber Reinforcement for Concrete." Concrete International,vol. 7, no. 3 (March 1985): 21 - 25.

Naaman, A. E., and M. H. Harajli. Mechanical Properties of HighPerformance Fiber Concretes: A State-Of-The-Art Report (SHRP-C/WP-90-004). SHRP National Research Council; Washington D.C., 1990.

Naaman, A.E., and F.M. Alkhairi. Fresh and Hardened Propern'es of HighEarly Strength Fiber Reinforced Concrete (HESFRC), Compressive Strengthand Modulus of Elasticity with Time. Depaaianent of Civil Engineering,University of Michigan, UMCE Report No. 91-08, August 1991, 211 pages.

165

Naaman, A.E., and F.M. Alkhairi. Flexural and Splitting Tensile Properties ofHigh Early Strength Fiber Reinforced Concrete. Depaztment of CivilEngineering, University of Michigan, Report No. UMCE 92-08, April 1992.

Reinhardt, H.W., and A.E. Naaman. High Performance Fiber ReinforcedCement Composites. (RILEM Proceedings 15), Chapman and Hall, London,1992.

Zia, P., M.L. L_mming,and S.H. Ahmad. High Performance Concretes: A State-of-the-Art Report.. Report no. SHRP-C-317. SHRP, National Research Council,Washington, D.C. 1991.

Compression

ACI Committ_ 318. Building Code Requirements for Reinforced Concrete(AC1318-83). American Concrete Institute, Detroit. 1983.

ACI Committee 544. "Measurement of Properties of Fiber ReinforcedConcrete." ACI Material Journal, vol.85, no. 6 (Nov-Dec 1988): 583 - 593.

Balaguru, P., and V. Ramakrishnan. Mechanical Properties of SuperplasticizedFiber Reinforced Concrete Developed for Bridge Decks and HighwayPavements. In Proceedings, Concrete in Transportation, ACI SP 93, Detroit(Sept 1986).

Balaguru, P., and V. Ramakrishnan. "Properties of Lightweight FiberReinforced Concrete. In Fiber Reinforced Concrete: Properties andApplications, SP 105-17, American Concrete Institute, Detroit (1987): 305 -322.

Bharyava, J.K. "Polymer-Modified Concrete for Overlays: Strength andDevelopment Characteristics." In Application of Polymer to Concrete, SP-69,American Concrete Institute, Detroit (1981): 205 - 218.

Fanella, D. A., and A. E. Naaman. "Stress-Strain Properties of FiberReinforced Concrete In Compression." ACI Journal, voi.82, no. 4 (July-August 1985): 475 - 483.

Homrich, J. R., and A. E. Naaman. "Stress-Strain Properties of SIFCON inCompression." Fiber Reinforced Concrete: Propern'es and Applications, SP105-16, American Concrete Institute, Detroit (1987): 283 - 304.

Mason, J.A. "Overview of Current Research on Polymer Concrete: Materialand Future Needs." In Application of Polymer to Concrete, SP-69, AmericanConcrete Institute, Detroit (1981): 1 - 20.

Mondragon, 1L Development of Material Properties for Slurry Infiltrated FiberConcrete (SIFCON)- Compressive Strength." New Mexico EngineeringResource Institute, Part 1 of 2 NMERI WA 8-18, Albuquerque (Dec 1985).

166

Mondragon, R. "SIFCON in Compression." Fiber Reinforced Concrete:Properties and Applications, SP 105-1, American Concrete Institute, Detroit(1987): 260 - 281.

Najm, H. "Mechanical Properties of High Performance Cement BasedComposites." Ph.D. thesis, Department of Civil Engineering, University ofMichigan. 1992.

Otter, D., and A. E. Naaman. "Steel Fiber Reinforced Concrete under Staticand Cyclic Compressive Loading." InProceedings of Third InternationalSymposium on Developments in Fiber Reinforced Cement and Concrete. R.N. Swamy, R. L. Wagstaffe, and D. R. Oakley. Sheffield, England (July1986).

Otter, D., and A.E. Naaman. "Model For Response of Concrete To RandomCompressive Loads." Journal of Structural Engineering, ASCE, vol. 115, no.11 (November 1989): 2794- 2809.

Soroushian, P., F. Aouadi, and M. Naji. "Latex-Modified Carbon FiberReinforced Mortar." ACI Material Journal, vol. 88, no. 1 (January/February1991): 11-18.

Bending

ACI Committee 544. "Design Considerations for Steel Fiber ReinforcedConcrete," ACI Structural Journal, vol. 85, no. 5 (Sep-Oct 1988): 563 - 580.

Akihama, S., M. Kobayashi, T. Suenaga, H. Nakagawa, and K. Suzuki."Effect of CFRC Specimen Geometry on Flexural Behavior." Paper presentedat the 3rd RILEM International Symposium on Fiber Reinforced CementComposites, Sheffield, England, 1986.

ASTM. Standard Test Method for Flexural Toughness and First-CrackStrength of Fiber-Reinforced Concrete (Using Beam with Third-PointLoading). ASTM C1018-89, vol. 04.02.

Balaguru, P., and V. Ramakrishnan. "Properties of Lightweight FiberReinforced Concrete." In Fiber Reinforced Concrete: Prope_'es andApplications, SP 105-17, American Concrete Institute, Detroit (1987): 305 -322.

Hibbert, A. P., and D.J. Hannant. "Toughness of Fibre Cement Composites."Composites, vol. 13 (Apr 1982): 105- 111.

Johnston, C.D. "Definition and Measurement of Flexural ToughnessParameters For Fiber Reinforced Concrete." Cement, Concrete, andAggregates, vol. 4, no. 2 (1982): 53 - 60.

Johnston, C. D. "precision of Flexural Strength and Toughness Parameters forFiber Reinforced Concrete." Cement, Concrete, and Aggregates, vol. 4, no. 2(1982): 61 - 67.

167

Johnston, C. D. "Steel Fiber Reinforced and Plain Concrete: FactorsInfluencing Flexural Strength Measurement." Journal of the American ConcreteInstitute, vol. 79, no. 2 (1982): 131 - 138.

Johnston, C. D., and R. J. Gray. "Flexural Toughness and First-CrackStrength of Fiber Reinforced Concrete." Paper presented at the 3rd RILEMInternational Symposium on Fiber Reinforced Cement Composites, Sheffield,England. July 1986.

Lira, T. Y., P. Paramasivam, and S L. Lee. "Bending Behavior of Steel-FiberConcrete Beams." ACI Structural Journal, vol. 84, no. 6 (Nov-Dec 1987): 524- 536.

Mangat, P. S., and K. Gurusamy. "Flexural Strength of Steel Fibre ReinforcedCement Composites." Journal of Material Science, vol. 22 (1987): 3103 -3110.

Ohama, Y., S. Kan, and M. Miyara "Flexural Behavior of Steel FiberReinforced Polymer-Modified Concrete." Transactions of the JapaneseConcrete Institute, vol. 4 (Dec 1982): 147 - 152.

Ramakrishnan, V., G. Y. Wu, and G. Hosalli. "Flexurai Behavior andToughness of Fiber Reinforced Concretes." Paper presented at the 68th AnnualMeeting of the Transportation Research Board. Washington, D.C. (January1989).

Ramakrishnan, V., W. V. Coyle, V. Kulandaisamy, and E. K. Schrader."Performance Characteristics of Fiber Reinforced Concrete With Low FiberContent." Journal of the American Concrete Institute, vol. 78, no. 5 (Sept-Oct1981): 388 - 394.

Sakai, M., and N. Nakamura. "Studies on Characteristics and FlexuralBehavior of Steel Fiber Reinforced Concrete." Japanese Concrete Institute, vol.2 (1984): 11 - 18.

Swamy, R. N., and S. A. A1-Ta'an. "Deformation and Ultimate Strength inFlexure of Reinforced Concrete Beams With Steel Fiber Concrete." Journal ofthe American Concrete Institute, vol. 78, no. 5 (Sept-Oct 1981): 395 - 405.

Tension

ACI Committee 544. Measurement of Properties of Fiber Reinforced Concrete,ACIMaterialJournal, vol. 85, no. 6 (Nov-Dec 1988): 583 - 593.

Johnston, C. D., and R. J. Gray. "Uniaxial Tensile Testing of Steel FibreReinforced Cementitious Composites." In Proceedings, RILEM Symposium onTesting and Test Methods of Fibre Cement Composites. Construction Press.Lancaster, England (1978): 451 - 461.

Laws, V. "Derivation of The Tensile Stress-Strain Curve from Bending Data."Journal ofMaterialScience, vol. 16 (1981): 1299- 1304.

168

Laws, V., and P. L. Walton. "The Tensile-Bending Relationships for FibreReinforced Brittle Matrices." In Proceedings, R1LEM Symposium, Testingand Test Methods of Fiber Cement Composites. R. N. Swamy, ed., Lancaster,England (1978): 429 - 438.

Lira, T. Y., P. Paramasivam,, and S. L. Lee. "Analytical Model For TensileBehavior of Steel-Fiber Concrete." ACI Material Journal, vol. 84, no. 4 (July-Aug 1987): 286 - 298.

Lira, T. Y., P. Paramasivam, M. A. Mansur, and S. L. Lee. "TensileBehavic,ur of Steel Fibre Reinforced Cement Composites." In RILEMSymposium Proceedings, FRC 86 Developments in Fiber Reinforced Cementand Concrete. Edited by R. N. Swamy, R. L. Wagstaffe, and D. R. Oaldey.vol. 1, July 1986.

Lub, K. B., and T. Padmoes. "Mechanical Behavior of Steel Fiber-CementMortar in Tension and Flexure, Interpreted By Means of Statistics." ACIMaterial Journal, vol. 86, no. I (Jan-Feb 1989): 16 - 27.

Naaman, A. E. "High Performance Fiber Reinforced Composites." InProceedings, Concrete Structures for the Future, IABSE Symposium, Paris,Versailles (1987): 371 - 376.

Nanni, A. "Splitting-Tension Test for Fiber Reinforced Concrete." ACIMaterial Journal, vol. 85, no. 4 (July-Aug 1988): 229 - 233.

Potrzebowski, J. "The Splitting Test Applied to Steel Fibre ReinforcedConcrete." International Journal of Cement Composites and LightweightConcrete, vol. 5, no. 1 (Feb 1983): 49 - 53.

Shah, S. P., P. Stroeven, D. Dalhuisen, and V. Stekelenburg. "CompleteStress-Strain Curves for Steel Fiber Reinforced Concrete in Uniaxial Tensionand Compression." In Testing and Test Methods of Fiber Cement Composites,RILEM Symposium, Construction Press, Lancaster (1978): 399 - 408.

Flexural Fatigue

Batson, G., C. Ball, L. Bailey, E. Landers, and J. Hooks. "Flexural FatigueStrength of Steel Fiber Reinforced Concrete Beams." Journal of the AmericanConcrete Institute, vol. 69, no. 11 (Nov 1972): 673 - 677.

Ramakrishnan, V., G. Oberling, and P. Tatnall. "Flexural Fatigue Strength ofSteel Fiber Reinforced Concrete." Fiber Reinforced Concrete: Properties andApplications, SP 105-13, American Concrete Institute, Detroit (1987): 225 -245.

Ramakrishnan, V., G. Y. Wu, and G. Hosalli. "Flexural Fatigue Strength,Endurance Limit, and Impact Strength of Fiber Reinforced Concretes." Paperpresented at the 68th Annual Meeting of the TransportationResearch Board.Washington, D.C., January 1989.

169

Ramakrishnan, V., S. GoUapudi, and R. Zellers. "PerformanceCharacteristics and Fatigue Strength of Polypropylene Fiber ReinforcedConcrete." In Fiber Reinforced Concrete: Properties and Applications, SP 105-9, American Concrete Institute, Detroit (1987): 159 - 177.

Ramakrishnan, V., T. Brandshaug, W. V. Coyle, and E. K. Schrader. "AComparative Evaluation of Concrete Reinforced with Straight Steel Fibers andFiber with Deformed Ends Glued "l'ogether in Bundles." Journal of theAmerican Concrete Institute, vol. 77, no. 3 (May 1980): 135 - 143.

Ramakrishnan, V. Coyle W. V., ¥. Kulandaisamy, and E.K. Schrader."Performance Characteristics of Fiber Reinforced Concrete with Low FiberContent." Journal of the American Concrete Institute, vol. 78, no. 5 (Sept-Oct1981): 388 - 394.

Pavement Applications

Hanna, A.N. "Steel Fibers Reinforced Concrete Properties in ResurfacingApplication." Research and Development Bulletin, RD 49.01P. PortlandCement Association, Skokie, Illinois (1977).

Shrader, E.K. Design Methods for Pavements with Special Concretes.American Concrete Institute Special Publication SP-81, Detroit (1984): 197 -212.

Johnston, C.D. "Steel Fiber Reinforced Pavements Trials." Concrete International,vol. 6, no. 12 (Dec. 1984): 39 - 43.

Packard, R.G., and G.K. Ray. Performance of Fiber Reinforced ConcretePavements. American Concrete Institute Special Publication SP-81, Detroit(1984): 325 - 349.

Shrader, E.K. "Fiber Reinforced Concrete Pavements and Slabs." Paperpresented at US Sweden Joint Seminar (NSF-STU), Stockholm (June 1985): 109 -131.

Wu, G., and M. Jones. "Navy Experience with Steel Fiber Reinforced ConcreteAirfield Pavement." In Fiber Reinforced Concrete Properties and Applications, SP-105, American Concrete Institute, Detroit (1987): 403 - 418.

170

Appendix A

Compression Tests

Table A.1 - A.16: Tables of Values of Pc and Ec for each Specimen and AverageValues and Standard Devision of each Series.

Fig. A.I - A.79: Stress versus Strain Curves for each Series and its

Representative Average Curve.

Fig. A.80 - A.94: Stress versus Strain Response with Time and Effect of

Cylindrical Size.

Fig. A.95 - A.104: Stress versus Strain response for Different Series.

Fig. A.105 - A. 111: Compressive Strength f'c.

Fig. A.112 - A.120: Elastic Modulus.

171

Table A.1. Ec and f'c Values for the Control Mix



Control 1D48fc 1 3976.4 4.74

Control 1D48fc2 4124.87 5.47

Control 1D48fc3 4287.56 5.03

Control-AV 1D48fcA 4129.61 5.08

Control-SD 1D48fcS 155.63 0.37

Control 1D612fcl --- 4.14

Control 1D612fc2 --- 4.83

Control-AV 1D612fcA --- 4.485

Control-S D 1D612fcS --- 0.49

Control 3D48fc 1 4434.05 6.66

Control 3D48fc2 4201.178 7.27

Control 3D48fc3 3829.906 5.73


Control-S D 3D48fcS 304.70 0.78

Control 7D48fcl 3826.6 7.14

Control 7D48fc2 4400.08 7.3

Control 7D48fc3 3889.85 6.33



Control 28D48fc 1 3852.337 7.5

Control 28D48fc2 3724.33 6.8

Control 28D48fc3 3804.466 6.7



172

Table A.2. Ec and f'c Values for the 30/50 Mix (Vf = 1% by)



A1%S3 1D48fcl 4616.34 5.75

A1%S3 1D48fc2 3938.67 5.96

A1%S3 1D48fc3 4671.34 6.2

A1%S3-AV 1D48fcA 4408.78 5.97

AI%S3-SD 1D48fcS 408.06 0.23

A1%S3 1D612fcl .... 5.1

A1%S3 1D612fc2 .... 6.05

A 1%S3-AV 1D612fcA .... 5.575

AI%S3-SD 1D612fcS .... 0.67

A1%S3 3D48fc I 4281.02 6.74

A 1%S3 3D48fc2 4051.88 6.53

A 1%S3 3D48fc3 3592.57 6.722

A 1%S3-AV 3D48fcA 3975.16 6.66

A 1%S3-SD 3D48fcS 350.58 0.12

A1%$3 7D48 fc 1 4695 7.1

A1%S3 7D48fc2 4438.13 7.5

A1%S3 7D48fc3 4800 8.03

A1%S3-AV 7D48fcA 4644.38 7.54

A1%S3-SD 7D48fcS 186.17 0.47

A 1%S3 28D48fc 1 5683 8.24

A1%S3 28D48fc2 4350 6.8

A 1%S3 28D48fc3 4300 7.98

A 1%S3-AV 28D48 fcA 4777.67 7.67

AI%S3-SD 28D48fcS 784.44 0.77

173

Table A.3. Ec and f'c Values for the 30/50 Mix (Vf = 2%)



A2%S3 1D48fcl 6846 6.2

A2%S3 1D48fc2 4563 5.9

A2%S3 1D48fc3 7798.58 6.1

A2%S3-AV 1D48fcA 6402.53 6.07

A2%S3-SD 1D48fcS 1662.75 0.15

A2%S3 1D612fcl --- 4.5

A2%S3 1D612fc2 --- 4.8

A2%S3-AV 1D612fcA --- 4.65

A2%S3-SD 1D612fcS --- 0.21

A2%S3 3D48 fc 1 4041.1 6.25

A2%S3 3D48fc2 4022.3 6.7

A2%S3 3D48fc3 4216.36 7.18

A2%S3-AV 3D48fcA 4093.25 6.71

A2%S3-SD 3D48fcS 107.03 0.47

A2%S3 7D48fcl 4704 7.4

A2%S3 7D48fc2 4353.11 7.5

A2%S3 7D48fc3 4036.87 7.76

A2% S3-AV 7D48fcA 4364.66 7.55

A2%S3-SD 7D48fcS 333.71 0.19

A2 %S3 28D48fc 1 3625.83 7.3

A2%S3 28D48fc2 3875.35 7.4

A2%S3 28D48fc3 4030.2 8.1

A2%S3-AV 28D48fcA 3843.79 7.60

A2%S3-SD 28D48fcS 204.02 0.44

174

Table A.4. Ec and f'e Values for the 50/50 Mix (Vf= 1%)



A1%S5 1D48fcl 3907 4.75

A 1%S5 1D48fc2 3403.5 5.1

A1%S5 1D48fc3 3180.4 5.3

A 1%S5-AV 1D48fcA 3496.97 5.05

A 1%S5-SD 1D48fcS 372.21 0.28

A1%S5 1D612fcl --- 5.2

A1%S5 1D612fc2 --- 6

AI%S5-AV 1D612fcA --- 5.6

AI%S5-SD 1D612fcS --- 0.57

A1%S5 3D48fcl 3436.4 5.6

A1%S5 3D48fc2 3634.45 5.7

A 1%S5 3D48 fc3 3497.3 5.85

A 1%S5-AV 3D48fcA 3522.72 5.72

AI%S5-SD 3D48fcS 101.44 0.13

A1%S5 7D48fcl 3601.8 5.1

A1%S5 7D48fc2 3740.91 6.5

A 1%S5 7D48fc3 3694.17 6.35

A 1%S5-AV 7D48fcA 3678.96 5.98

A1%S5-SD 7D48 fcS 70.79 0.77

A1%S5 28D48fcl 2689.37 5.5

A1%S5 28D48fc2 2413.3 6.6

A1%S5 28D48fc3 2992 6.8

AI%S5-AV 28D48fcA 2698.22 6.30

A1%S5-SD 28D48fcS 289.45 0.70

175

Table A.5. Ec and f'c Values for the 0.75 in. Long Polypropylene Mix (Vf = 1%)


(ksi) Stren[th (ksi)A1%P0.75 1D48fc 1 2889 4.22

A1%P0.75 1D48fc2 2700.66 4.08

Al%P0.75 1D48fc3 3188.54 ---

A1%P0.75-AV 1D48fcA 2926.07 4.15

Al%P0.75-SD 1D48fcS 246.04 0.10

A 1%P0.75 1D612fc 1 --- 4.4

Al%P0.75 1D612fc2 --- 4.65

Al%P0.75-AV 1D612fcA --- 4.525

A 1%P0.75-SD 1D612fcS --- 0.18

A1%P0.75 3D48fc 1 3055.11 4.57

A1%P0.75 3D48fc2 3139.75 5.11

A1%P0.75 3D48fc3 3170.15 5.17

Al%P0.75-AV 3D48fcA 3121.67 4.95

A1%P0.75-SD 3D48fcS 59.61 0.33

A1%P0.75 7D48fc 1 3284.55 5.9

A1%P0.75 7D48fc2 3197.18 6

A1%P0.75 7D48fc3 3262.208 5.6

Al%P0.75-AV 7D48fcA 3247.98 5.83

Al%P0.75-SD 7D48fcS 45.39 0.21

A 1%P0.75 28D48 fc 1 2901.07 5.67

A 1%P0.75 28D48fc2 3006.11 5.44

A1%P0.75 28D48fc3 3004.9 5.56

Al%P0.75-AV 28D48fcA 2970.69 5.56

Al%P0.75-SD 28D48fcS 60.30 0.12

176

Table A.6. Ec and f'c Values for the 0.75 in. Long Polypropylene Mix (Vf = 2%)



A2%P0.75 1D48fc 1 2881.6 2.8

A2%P0.75 1D48fc2 2784.7 3i

A2%P0.75 1D48fc3 2688.9 3.4

A2%P0.75-AV 1D48fcA 2785.07 3.07

A2%P0.75-SD 1D48fcS 96.35 0.31

A2%P0.75 1D612fcl --- 2.2

A2%P0.75 1D612fc2 --- 3

A2%P0.75-AV 1D612fcA --- 2.6

A2%P0.75-SD 1D612fcS --- 0.57

A2% P0.75 3D48 fc 1 2947.28 4.41

A2%P0.75 3D48fc2 3044.25 4.1

A2%P0.75 3D48fc3 2997.02 4.57

A2%P0.75-AV 3D48fcA 2996.18 4.36

A2%P0.75-SD 3D48fcS 48.49 0.24

A2%P0.75 7D48fcl 2667 4.41

A2%P0.75 7D48fc2 2513.4 4.29

A2%P0.75 7D48fc3 2848.95 5.05

A2%P0.75-AV 7D48fcA 2676.45 4.58

A2%P0.75-SD 7D48fcS 167.97 0.41

A2%P0.75 28D48fc 1 2560.88 4.25

A2%P0.75 28D48fc2 2635.96 4.65

A2%P0.75 28D48fc3 2764.75 5.4

A2%P0.75-AV 28D48fcA 2653.86 4.77

A2%P0.75-SD 28D48fcS 103.11 0.58

177

Table A.7 - Ec and f'c Values for the 30/50 + 50/50 Hybrid Mix (Vf = 1%)

Mix ID Specimen ]D Elastic Modulus Compressive

(ksi) Strength (ksi)A 1%S3S5 1D48fc 1 3938.115 5.83

A 1%S3S5 1D48fc2 3811.25 5.01

A 1%$3S5 1D48fc3 3741.72 5.69

A 1%S3S5-AV 1D48fcA 3830.36 5.51

A l%S3S5-SD 1D48fcS 99.58 0.44

A1%S3S5 1D612fcl --- 4.03

A1%S3S5 1D612fc2 --- 4.14

AI%S3S5-AV 1D612fcA --- 4.085

A 1%S3S5-SD 1D612fcS --- 0.08

A 1%S3S5 3D48fc 1 1770.72 6.38

A 1%S3S5 3D48fc2 1994.05 6.4

A 1%S3S5 3D48fc3 2001.3 6

A I%S3S5-AV 3D48fcA 1922.02 6.26

A 1%S3S5-SD 3D48fcS 131.08 0.23

A1%S3S5 7D48fc 1 3540.97 6.37

A1%S3S5 7D48fc2 3628.95 7.52

A 1%S3S5 7D48fc3 3529.15 6.9

A 1%S3S5-AV 7D48fcA 3566.36 6.93

A 1%S3S5-SD 7D48fcS 54.53 0.58

A 1%S3S5 28D48fc 1 3923.94 7.64

A1%S3S5 28D48fc2 3889.53 7.89

A1%S3S5 28D48fc3 4016.71 8.12

AI%S3S5-AV 28D48fcA 3943.39 7.88

AI%S3S5-SD 28D48fcS 65.78 0.24

178

Table A.10. Ec and f'c Values for the 30/50 + Polypropylene Hybrid Mix (Vf = 2%)


(ksi) Stren[th (ksi)

A2%S3P0.5 1D48fcl 3422.08 4.35

A2%S3P0.5 1D48fc2 3512.45 4.75

A2%S3P0.5 1D48fc3 3381.56 5.01

A2%S3P0.5-AV 1D48fcA 3438.70 4.70

A2%S3P0.5-SD 1D48fcS 67.01 0.33

A2%S3P0.5 1D612fcl --- 3.64

A2%S3P0.5 1D612fc2 --- 3.71

A2%S3P0.5-AV 1D612fcA --- 3.675

A2%S3P0.5-SD 1D612fcS --- 0.05

A2%S3P0.5 3D48fc 1 3531.66 5.06 ,I

A2%S3P0.5 3D48fc2 3475.15 5.32

A2%S3P0.5 3D48fc3 3583.05 5.13

A2%S3P0.5-AV 3D48fcA 3529.95 5.17

A2%S3P0.5-SD 3D48fcS 53.97 0.13

A2%S3P0.5 7D48fc 1 2989.48 4.06

A2%S3P0.5 7D48fc2 2923.34 6.43

A2% S3P0.5 7D48fc3 3063.57 6.02

A2%S3P0.5-AV 7D48fcA 2992.13 5.50

A2%S3P0.5-SD 7D48fcS 70.15 1.27II

A2%S3P0.5 28D48fcl 1574.86 5.98

A2%S3P0.5 28D48fc2 1428.16 6.22

A2%S3P0.5 28D48fc3 1542.05 5.91

A2%S3P0.5-AV 28D48fcA 1515.02 6.04

A2%S3P0.5-SD 28D48fcS 76.99 0.16

179

Table A.11. Ee and f'c Values for the Latex Control Mix (Vf = 0%)

Mix ID Specimen I]) Elastic Modulus Compressive


B0%Con 1D48fcl 2191.8 4.45

B0%Con 1D48fc2 2352.8 4.22

B0%Con 1D48fc3 ......

B0%Con-AV 1D48fcA 2272.3 4.34

B0%Con-SD 1D48fcS 113.84 0.16

B0%Con 1D612fcl ......

B0%Con 1D612fc2 ......

B0%Con-AV 1D612fcA ......

B0%Con-SD 1D612fcS ......

B0%Con 3D48fc 1 4713 6.24

B0%Con 3D48fc2 2800 6.25

B0%Con 3D48fc3 ......

B0%Con-AV 3D48fcA 3756 6.25

B0%Con-SD 3D48fcS 1352 0.01

B0%Con 7D48fc 1 3065 5.83

B0%Con 7D48fc2 4615 6.51

B0%Con 7D48fc3 ......

B0%Con-AV 7D48fcA 3840 6.17

B0%Con-SD 7D48fcS 1096 .48

B0%Con 28D48fc 1 3431 7.8

B0%Con 28D48fc2 3590 8.45

B0%Con 28D48fc3 ......

B0%Con-AV 28D48fcA 3510 8.13

B0%Con-SD 28D48fcS 112.43 0.46

180

Table A.12. Ee and f'e Values for the 50/50 Mix Plus Latex (Vf= 1%)



B1%S5 1D48fcl 3155.3 4.2

B1%S5 1D48fc2 3101.1 4.5

B 1%S5 1D48fc3 3174.12 4.8

B 1%S5-AV 1D48fcA 3143.51 4.50

B 1%S5-SD 1D48fcS 37.91 0.30

B1%S5 1D612fcl --- 3.08

B1%S5 1D612fc2 --- 3.3

BI%S5-AV 1D612fcA --- 3.19

BI%S5-SD 1D612fcS --- 0.16

B 1%S5 3D48fcl 4089.4 5.9

B 1%S5 3D48fc2 4151.1 5.85

B 1%S5 3D48fc3 4245.45 5.5

B 1%S5-AV 3D48fcA 4161.98 5.75

B I%S5-SD 3D48fcS 78.59 0.22

B 1%S5 7D48fcl 3536.09 5.03

B 1%S5 7D48fc2 3381.81 5.3

B 1%S5 7D48fc3 ......

B 1%S5-AV 7D48fcA 3458.95 5.17

BI%S5-SD 7D48fcS 109.09 0.19

B 1%$5 28D48fc 1 7604.66 6.4

B 1%S5 28D48fc2 8057.87 6.91

B 1%S5 28D48fc3 7385.35 6.05

B I%S5-AV 28D48fcA 7682 6.45

B I%S5-SD 28D48fcS 155.08 0.43

181

Table A.8. Ec and f'c Values for the 30/50 + 50/50 Hybrid Mix (Vf-- 2%)

Mix ID Specimen IT) Elastic Modulus Compressive


A2% $3S5 1D48fc 1 2531.32 3.15

A2%S3S5 1D48fc2 2443.66 3.28

A2%S3S5 1D48fc3 2669.8 3.17

A2%S3S5-AV 1D48fcA 2548.26 3.20

A2%S3S5-SD 1D48fcS 114.02 0.07

A2%S3S5 1D612fcl --- 5.08

A2%S3S5 1D612fc2 --- 5.05

A2%S3S5-AV 1D612fcA --- 5.065

A2%S3S5-SD 1D612fcS --- 0.02m i

A2%S3S5 3D48fcl 2805.18 2.97

A2%S3S5 3D48fc2 2767.2 3.83

A2%S3S5 3D48fc3 2883.73 3.34

A2%S3S5-AV 3D48fcA 2818.70 3.38

A2%S3S5-SD 3D48fcS 59.43 0.43

A2%S3S5 7D48fc 1 3305.9 4.66

A2%S3S5 7D48fc2 3447 6.22

A2%S3S5 7D48fc3 3454.23 5.13

A2%S3S5-AV 7D48fcA 3402.38 5.34

A2%S3S5-SD 7D48fcS 83.63 0.80

A2%S3S5 28D48fcl 3563.7 7.77

A2%S3S5 28D48fc2 3315.16 6.1

A2%S3S5 28D48fc3 3492.42 6.86

A2%S3S5-AV 28D48fcA 3457.09 6.91

A2%S3S5-SD 28D48fcS 127.98 0.84

182

Table A.9. Ec and f'c Values for the 30/50 + Polypropylene Hybrid Mix (Vf = 1%)


,, (ksi) Stren[th (ksi)A1%S3P0.5 1D48fc 1 2454.42 3.05

A1%S3P0.5 1D48fc2 2566.42 3.83

A1%S3P0.5 1D48fc3 2435.07 3.26

A1%S3P0.5-AV 1D48fcA 2485.30 3.38

AI%S3P0.5-SD 1D48fcS 70.91 0.40

Al%S3P0.5 1D612fcl --- 3.6

Al%S3P0.5 1D612fc2 --- 3.7

AI%S3P0.5-AV ID612fcA --- 3.65

AI%S3P0.5-SD 1D612fcS --- 0.07

A1%S3P0.5 3D48fc 1 2817.88 3.4

Al%S3P0.5 3D48fc2 2907.86 4.1

Al%S3P0.5 3D48fc3 2855.06 4.1

AI%S3P0.5-AV 3D48fcA 2860.27 3.87i t

AI%S3P0.5-SD 3D48fcS 45.22 0.40

Al%S3P0.5 7D48fcl 3215.7 5.03

A 1%S31:'0.5 7D48fc2 3007.7 4.7

A 1%S3P0.5 7D48fc3 2911.77 3.68

AI%S3P0.5-AV 7D48fcA 3045.06 4.47

AI%S3P0.5-SD 7D48fcS 155.37 0.70

A 1%S3P0.5 28D48fc 1 2611.7 4.76i

A 1%S3P0.5 28D48fc2 2764.5 5.11

A1%S3P0.5 28D48fc3 2742.01 4.84

AI%S3P0.5-AV 28D48fcA 2706.07 4.90

AI%S3P0.5-SD 28D48feS 82.50 0.18

183

Table A.13. Ec and f'c Values for the Polypropylene Mix Plus Latex (Vf = 1%)

Mix ID Specimen 1]) Elastic Modulus Compressive

(ksi) Strength (ksi)B 1%P0.5 1D48fc 1 2279.24 2.65

B 1%P0.5 1D48fc2 2492.11 3.15

B 1%P0.5 1D48fc3 2025.97 3

B 1%P0.5-AV 1D48fcA 2265.77 2.93

B 1%P0.5-SD 1D48fcS 233.36 0.26

Bl%P0.5 1D612fcl --- 3

B 1%P0.5 1D612fc2 --- 3.1

B 1%P0.5-AV 1D612fcA --- 3.05

B 1%P0.5-S D 1D612fcS --- 0.07

B 1%P0.5 3D48fc 1 2665.7 4

B 1%P0.5 3D48fc2 2816.82 4.4

B 1%P0.5 3D48fc3 2901.42 4.52

B 1%P0.5-AV 3D48fcA 2794.65 4.31

B 1%P0.5-SD 3D48fcS 119.41 0.27

B 1%P0.5 7D48fc 1 2764.12 3.5

B 1%P0.5 7D48fc2 2992.4 4.7

B 1%P0.5 7D48fc3 2816.86 5.2

B 1%P0.5-AV 7D48fcA 2857.79 4.47

B 1%P0.5-SD 7D48fcS 119.52 0.87

B 1%P0.5 28D48fc 1 6211 5.5

B 1%P0.5 28D48fc2 6623.5 5.52

B 1%P0.5 28D48fc3 6965.6 6.35

B 1%P0.5-AV 28D48fcA 6600.03 5.79

B 1%P0.5-SD 28D48fcS 377.85 0.49

184

Table A.14. Ec and f'c Values for the 50/50 Mix Plus Silica Fume (Vf = 1%)



C 1%S5 1D48fc 1 3763.57 5.38

C1%$5 1D48fc2 3806.61 5.61

C1%S5 1D48fc3 3404.84 5.38

CI%S5-AV 1D48fcA 3658.34 5.46

CI%S5-SD 1D48fcS 220.59 0.13

C1%$5 1D612fcl --- 5.03

C1%S5 1D612fc2 --- 5.8

CI%S5-AV 1D612fcA --- 5.415

CI%S5-SD 1D612fcS --- 0.54

C1%S5 3D48fc 1 2036.43 5.6

C1%$5 3D48fc2 2011.29 5.7

C1%$5 3D48fc3 1870.92 6.4

C 1%S5-AV 3D48fcA 1972.88 5.90

C1% S5-SD 3D48fcS 89.19 0.44

C1%$5 7D48fcl 4004.7 7.1

C1%$5 7D48fc2 4184.2 8

C1%S5 7D48fc3 ......

C1%S5-AV 7D48fcA 4094.45 7.55

CI%S5-SD 7D48fcS 126.93 0.64

C 1%S5 28D48 fc 1 2782.5 9.05

C 1%S5 28D48fc2 2171.09 7.75

C1%$5 28D48fc3 ......

C 1%S5-AV 28D48fcA 2476.80 8.40

C1%S5-SD 28D48fcS 432.33 0.92

185

Table A.15. Ee and f'c Values for the Polypropylene Mix Plus Silica Fume(Vr= 1%)

Mix ID Specimen 113 Elastic Modulus Compressive


C 1%P0.5 1D48fc 1 2843.23 3.3

C1%P0.5 1D48fc2 2876.49 3.2

C 1%P0.5 1D48 fc3 2719.45 3.85

C1%P0.5-AV 1D48fcA 2813.06 3.45

CI%P0.5-SD 1D48fcS 82.75 0.35

Cl%P0.5 1D612fcl --- 4

Cl%P0.5 1D612fc2 --- 3.8

CI%P0.5-AV 1D612fcA --- 3.9

CI%P0.5-SD 1D612fcS --- 0.14

C 1%P0.5 3D48fc 1 3635.99 5.5

C 1%P0.5 3D48fc2 3490.99 5.65

Cl%P0.5 3D48fc3 3783.55 3.27

C 1%P0.5-AV 3D48fcA 3636.84 4.81

C1%P0.5-SD 3D48fcS 146.28 1.33

C 1%P0.5 7D48fc 1 3512.42 5.3

C1%P0.5 7D48fc2 3414.59 6.01

C1%P0.5 7D48fc3 3234.7 5.43

C1%P0.5-AV 7D48fcA 3387.24 5.58

C1%P0.5-SD 7D48fcS 140.87 0.38

Cl%P0.5 28D48fcl 2880.3 4.93

Cl%P0.5 28D48fc2 2993 6.21

C1%P0.5 28D48fc3 2897.75 6.53

C1%P0.5-AV 28D48fcA 2923.68 5.89

CI%P0.5-SD 28D48fcS 60.66 0.85

186

Table A.16. Ec and f'c Values for the 30/50 + 50/50 Hybrid Mix Plus SilicaFume (Vf = 1%)



C1%S3S5 1D48fcl 3226.78 4.5

C1%S3S5 1D48fc2 3365.8 4.93

C 1%S3S5 1D48fc3 3257.4 4.92

CI%S3S5-AV 1D48fcA 3283.33 4.78

CI%S3S5-SD 1D48fcS 73.05 0.25

C1%$3S5 1D612fcl --- 4.6

C1%$3S5 1D612fc2 --- 4.75

CI%S3S5-AV 1D612fcA --- 4.675

CI%S3S5-SD 1D612fcS --- 0.11

C1%S3S5 3D48fc 1 4288.15 5.54

C1%S3S5 3D48fc2 4320 5.61

C1%S3S5 3D48fc3 4154.01 5.32

C1%S3S5-AV 3D48fcA 4254.05 5.49

CI%S3S5-SD 3D48fcS 88.09 0.15

C 1%S3S5 7D48fc 1 3422 7.03

C1%$3S5 7D48fc2 3549 7.83

C1%$3S5 7D48fc3 3370.08 7.15

C1%S3S5-AV 7D48fcA 3447.03 7.34

C1%S3S5-SD 7D48fcS 92.05 0.43

CI%$3S5 28D48fcl 2872.3 8.11

C1%$3S5 28D48fc2 3318.2 7.32

C 1%S3S 5 28D48fc3 3422.25 6.76

CI%S3S5-AV 28D48fcA 3204.25 7.40

CI%S3S5-SD 28D48fcS 292.15 0.68

187

FRC - Test: a¢ ! day- Controt HIxm

- Cylinder- size, 4" x 8'

U1 u5 , Average Curve___'J It I

;I• rl I

(/) _r ',I t

LLJ _,

I

i' ii i• i

• I ""1 I._ 1 1 I 1 1 !!

.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. A.1 - Stress vs. Strain Response of Control Mix, 1 Day, 4"x 8" Cylinders

FRC - Tes¢ a¢ 3 days

,, Cont:rot Mix

Cylinder size, 4' x 8'

__ I_ Average Cumve%J

UJrv_p-

:f,00 ,01 ,02 ..03 ,04 ,05 ,06

STRAIN

Fig. A.2 - Stress vs. Strain Response of Control Mix, 3 Days, 4"x 8" Cylinders

188

,00 .01 .02 .03 .04 .05 .06

STRAIM


o_

o5 F'RC- Tes1: (;t: 28 daysCon'trot Mix

r,iCytlnder" size, 4' x 8'

y, Average Curvevu i(/)(/) .ILl '¢rv

.00 ,01 .02 .03 ,04 ,05 .06

STRAIN


189

_f FRC - Test at I dr,y

30/50 Hooked Fibers, t/d=60VF = I_.(oF Conc're'te)

Cytlnder size, 4' x 8'

N

M

.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. A.5 - Stress vs. Strain Response of A1%S3,1 Day, 4"x 8" Cylinders

/• I'- F'RC - Test ¢L't 3 d_ys

r,,.r- . 30/50 Hooked Fiber-s, |/d=60

._- /_, VF = lY. ( oF Concr'e,e)

,.o_ :f ;'_,. Ct,jtlnder size, 4' x 8'

.00 .01 .0;_ .03 .04 .05 .06

STRAIH

Fig.A.6 - Stressvs.Strain Responseof A1%S3,3 Days,4"x 8" Cylinders

190

t.

FRC - Tes_ o"k ;7 doysrC ,, 30/50 Hooked Fibers, t/d=60

Vf = 1:/.( oF Concrete)

Cylinder size, 4' x 8'

ui Averoge Curve.X '.

wr_ l ' ,i-- , ",, F,

•..... '+, o..,,,.s

.00 .01 .0;:' ,03 .04 .05 .06

STRAIN

Fig. A.7 - Stress vs. Strain Response of A1%S3,7 Days, 4"x 8" Cylinders

o_m

. FRC - Tes+ o't 28 cloysco 30/50 Hooked Fibers, t/d=60

rC VF = W. ( oF Concrete)Cytlnder size, 4' x 8'

m _

v_ _ Averooe Curveui

O0C_L_ry

(/)r_ ,,rt_

', %,bi

.

.OO .01 .O@ .03 .04 .05 .06

STRAIM

Fig. A.8 - Stress vs. Strain Response of AI %S3,28 Days, 4"x 8" Cylinders

191

_f F'RC - Test ot; t d;y

30/50 Hooked Fibers, t/d=60VF = 2_. ( oF Concre*e)

,, Cylinder size, 4" x 8"

UI Iri- 'I__' ", Aver'G,e Cur-reV -- ff |ltltt_ i,

(,4_:- _"_, ",.

ry ei- '",', '",,i *, "l t

_ b L_

,..,_I I I I I I I I I I I.00 .01 .OEZ .03 .04 .05 .06

STRAIM

Fig. A.9 - Stress vs. Strain Response of A2%S3,1 Day, 4"x 8" Cylinders

/._ .. FRC - Tes't a't 3 daws

h E ;'_, 30/50 Hooked Fibers, I./d=60I :I.,,_;,, vf l eX ( Or Corlcr'_e"_e)

Cy==d,,-,,de,,'x e'

*t i

ww : ,2:,

.00 .01 .0::) .03 .04 .05 .06

STRAIN

Fig. A.10 - Stressvs. StrainResponseof A2%S3,3 Days,4"x 8" Cylinders

192

oi

FRC - Test at 7 days30/50 Hooked Fiber's, t/d=60

',, VF = 2?, ( oF Concrete),_ Cy|lnder size, 4' x 8'

Uly u5 AverQge CurveV

(/) _:-

W -rwH_

I-- "_.

.00 .Or .02 ,03 .04 .05 .06

STRAIH


o_

FRC - Test at 28 d,_ys"t'_ 30/50 Hooked Fibers, t/d=60

Vf = 2_. ( oF Concrete)r_ r,

Cytlnder"slze, 4' x 8'

__ Aver'Qge Curve

vu5 _,mt

(/) I_L,J_Fryp-

it,V,T_II,.,.

.00 ,01 .02 ,03 .04 .05 .06

STRAIPI


193

cL

- F'RC - Tes't cL_cI day- 50/50 Hooked Fibers, [/d-lO0- VF = 1_. ( oF Concrel:e)

,_ - Cylinder size, 4' x 8'

.00 .01 ,02 .03 .04 ,08 .06STRAIM

Fig. A.13 - Stress vs. Strain Response of AI%SS, 1 Day, 4"x 8" Cylinders

_f F'RC - Test; Qt; :3 days

50/50 Hooked Fibers, t/d:lO0VF --- 1_. ( of Concre'te)

_v -- /'''''" Cylinder size, 4' x 8'u')" ;' '*,. Aver-age Curve! t

I I

! I

.00 .01 .OP .03 .04 .05 .06

STRAIM


194

0o

FRC - Test at 7 days

50/50 Hooked Fibers, [/d=lO0

VP = ;Y, ( oF Concrete)

CyLinder size, 4' x 8'

U) ui Average CurveY

(/) t"

i,i

_,:_ "%,

• v1_" .

' _'_i,o1.,pf ..

,00 .01 .02 ,03 ,04 .05 .06

STRAIM


o; /.I- FRC - Test Qt 88 days

®L_ so/soHookedFibers,t/d=lO0r-

I- VF = IX.( oF Concrete)

h i- ,4,:,, CyLinder size, 4' x 8"

o i Itu')l- ,I,' _\ ',

,00 .01 .08 .03 .04 .05 .06

STRAIN


195

co

FRC - Test at I day

r_- 3/4' PolupropyteneF'Ibers- VP = 1X ( oF Concrete)

,3- Cytlnderslze,4' x 8'

..__- Aver,,geCurvem

bJ

h-ntri ' ",

J i I I I I I I I I I.00 .01 .02 ,03 .04 .05 .06

STRAIM

Fig. A.17 - Stress vs. Strain Response of AI%P0.75,1 Day, 4"x 8" Cylinders

. FRC - Test at 3 days3/4' Potupropytene Fibers

- VF = IX ( o# Concrete)

- CyLinder size, 4' x 8'

y _ Average CurveV

oo_

1J

nzeih"°t.L

LI

I I I I I -'1...... i..... .I I I I.00 .01 .08 .03 .04 ,05 ,06

STRAIM

Fig. A.18 - Stressvs. StrainResponseof AI%P0.75,3 Days,4"x 8" Cylinders

196

_| L FRC - Test at 7 days

E 3/4' PotypropyLene FibersVF = 17. ( oF Concrete)

,, Cytmder size, 4' x 8'

_ I _ AverQge CurveYV

(/)

rYt_ _,(/)

(_ b,/i . •

I ll_

".t*. •

I I I i I ! I I I I I,00 .01 .02 .03 ,04 .05 .06

STRAIH

Fig. A.19 - Stress vs. Strain Response of Al%P0.75,7 Days, 4"x 8" Cylinders

FRC - Test Qt P8 d_ys

r( L 3/4' Po|ypropytene Fibers-L VF = i?. { oF Concrete)

_F , CyLinder size, 4' x 8'

_c,i : ','

iI I_I_ • %"t

.00 .01 .08 .03 .04 .05 .06

STRAIH

Fig. A.20 - Stress vs. Strain Response of Al%P0.75,28 Days, 4"x 8" Cylinders

197

m

FRC - Tes't at 1 dayr_.- 3/4' Po|t,jpropytene Fibers

- VF = 2_. ( of Concre'te)

,_- Ctjtlnder size. 4' x 8'

m__Cui- Average CurveV m

(_-

bJ "

n, _ ,,_,

. ' P, t.. t.

_:_" I I I I I I.00 .Or .02 .03 .04 .05 ,06

STRAIN

Fig. A.21 - Stress vs. Strain Response of A2%P0.75,1 Day, 4"x 8" Cylinders

°

m. - F'RC- Tes'_ at 3 d_ysr,, - 3/4' Pottjpropytene Fibers

- VF = PX ( oF Concre'te)

'_ - Cy|lnder size. 4" x 8'

v_Ui Average Curve• II tI

.b/t;

.00 .0! .02 .03 .04 .05 .06

STRAIM

Fig. A.22 - Stress vs. Strain Response of A2 %P0.75,3 Days, 4"x 8" Cylinders

198

0_

- F'RC- Tes'¢ at 7 dQujsr_- 3/4' Polypropt,jiene Fibers

- Vf = 2_. ( oF Concre'te)

q)" CyLinder size. 4" x 8'

_- ,',, Average Curveu5

I.* It

l_c,i i '.

",. ',,....

.UO .01 .02 .03 ,04 .05 .0(

STRAIM

Fig. A.23 - Stress vs. Strain Response of A2%P0.75,7 Days, 4"x 8" Cylinders

m

F'RC- Tes't: _'t 88 d,,ys3/4' Polypropytene Fibers

VF = ;_Y. ( oF Concre'te)

q) - Ct,jtlnder size, 4' x 8'

y _ - , --Averoge Curve

v ',

t tt I

I-'_ "_,',_ 2"."; / "'"-2.2.22-:.2. I " F, i --'-_-" '"- - l l I.00 .01 .OP .03 .04 .05 .06

STRAIM

Fig. A.24 - Stress vs. Strain Response of A2%P0.75,28 Days, 4"x 8" Cylinders

199

- FRC - Test at I day

- Hybrld Hlx

- 30/50 + 50/50 Hooked Flbers

- ," VF = 1% ( oF Concrete)

==_ m . •In I-- il_s'_"_;- Cylinder size, 4' )( 8'

I- ;F,1:'_!_J',, _ Average Curve.1 ,i: !-:J_'i',,

_ _'r- _1; "_th_'l,,

:1: ,,,,%r;,t

• '','i'l ,..

2....,00 .Or 32 .03 .04 ,05 .06

STRAIFI

Fig. A.25 - Stress vs. Strain Response of A1%S3S5,1 Day, 4"x 8" Cylinders

o

_f FRC - Test at 3: da_jsH_Jbrld HIx30/50 + 50/50 Hooked Fibers

'i" Vf = 1% ( o? Concrete)i f

:; '., C_jtlnder slzel 4' X 8 l

" [,,_ _, _ Average CurveI f

i

_ _ " "i_"I I t,

I I

I!

I I I I I I I ..... 1..... I I I,00 .Ot ,OP .03 .04 ,05 36

STRAIM

Fig. A.26 - Stressvs. StrainResponseof AI%S3S5,3 Days,4"x 8" Cylinders

200

o5

', FRC - Test at 7 daysr_ Hybrid Mix

30/50 + 50/50 Hooked FibersVF = IX ( o_ Concre_¢e)

._ L

V)__ _ Cylinderslze,4" x 8'v Average Curve

C_bJr_e_p-

,,

,00 .01 .02 .03 ,04 .05 .06

STRAIH

Fig. A.27. Stress vs. Strain Response of AI%S3S5,7 Days, 4"x 8" Cylinders

o5

FRC - Test at 28 dags

: ', Hujbrld Mix

"30/50 + 50/50 Hooked FibersVf = 1X ( o_ Concrete)

INtA ,'_,,_ Cylinder size, 4' x 8', ,, , Average Curve

"-".... :222"

.00 .01 ,02 .03 ,04 .05 .06

STRAIH

Fig. A.28 - Stress vs. Strain Response of A1%S3S5,28 Days, 4"x 8" Cylinders

201

00

.- FRC - Test Qt 1 d_j

- Hybrid HIx

- 30/50 + 50/50 Hooked Fibers

- VF = 2_ ( oF Concrete)

_- Cgtlnder size# 4' x e'v _ ,., Average Curve

,00 .01 ,OP .03 .04 ,05 .06

STRAIH

Fig. A.29 - Stress vs. Strain Response of A2 %S3S5,1 Day, 4"x 8" Cylinders

o5

FRC - Test =± 3 d=ysP_ Hybrid HIx

30/50 + 50/50 Hooked Fibers

VF = 27. ( oF Concrete)

y It_ C_jtlnder slze_ 4" x 8'v _ Average Curve

I.I , "

I"- .i.t-,'_';""

plI

.00 .01 ,OP ,03 ,04 ,05 ,06

3TRAIh

Fig. A.30 - Stress vs. Strain Response ofA2%S3S5,3 Days, 4"x 8" Cylinders

202

OO

-- FRC - Tes_ o¢ ;7 dogs

- Hybrid HIx30/50 + 50/50 Hooked Fibers

q)- ,, ', VP = 1_. (o_ Concrete)

U_r- _ ,_. Cgtlnder slzeJ 4' x 8'

',,, ,.,_ -- Averoge Curve_'¢- i

I I I I I I iI/ I I I I

.00 ,01 .02 .03 .04 .05 .06

STRAIM


o

'' FRC - Tes_ a'_ 28 dogs

,, Hybrid Mix•' 30._50 + 50/50 Hooked FIIoer_

VF = 27. ( oF Concrete)i

.__ _ ., CgUnder size, 4' x 8'i

"-" " -- Averoge Curve

rv'e_ , ,,

.i

.00 .01 .OP .03 .04 .05 .06

STRAIH


203

0d

FRC - Tes'ta'tI d,,y

r_ HybridHlx3/4' Potypropyiene+

',o 30/50 Hooked Fibers,VF = 1%

__s_ Cytlnder size, 4' x B'Average Curve

fti _,

t

,00 ,01 ,02 ,03 .04 .05 .06

STRAIN

Fig. A.33 - Stress vs. Strain Response of A I %S3P0.7_:, 1 Day, 4"x 8" Cylinders

FRC - Test nt 3 days

HybrldHIx3/4' Potypropytene+30/50 Hooked Fibers, VF = 1%

V_ _ Cylinder size, 4' x 8"

v _ Average Curve

C,qbJ

rvr_ '_7,.-,.p-

.00 .01 ,OP .03 .04 .05 .06

STRAII'i

Fig. A.34 - Stressvs. StrainResponseof Al%S3P0.75,3 Days,4"x 8" Cylinders

204

o_

- FRC - Test _ 7 d_ys- Hybrid Mix- 3/4' Potypropylene +- 30/50 Hooked Fibers. V_ = 1_.

u_.- ,,,, Cylinder size, 4' x 8'L ,,7,,, __ Averoge Curve

. I _

.00 .01 .02 .03 .04 .05 .06

STRAIrl

Fig. A.35 - Stress vs. Strain Response of Al%S3P0.75,7 Days, 4"x 8" Cylinders

- FRC - Tes± Qt 28 d_ys

- Hybrid Mlx

.- 3/4' Potgpropytene +

- 30/50 Hooked Fibers, VF = I_.

_ _1-,', Cytlnder size, 4' x 8'__,v.,°oocoov.

.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig.A.36. Stressvs.StrainResponseofAl%S3P0.75,28Days,4"x8" Cylinders

205

o_

- FRC - Test at I day

- HybridM;x- 3/4" Potgpropyiene +

- 30/50 Hooked Fibers VF ='.27.

I_- ,-, Cylinder size, 4' x 8

I- ,"/_:_', __ A_er=Oecurve

_ ' ,

_i _ ',

.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. A.37 - Stress vs. Strain Response of AZ%S3P0.75, I Day, 4"x 8" Cylinders

m

FRC - Test ot 3 days

Hybrid Mix

- 3/4' Pot_prop_jtene +

- 30/50 Hooked Fibers, VF = 2?.S'%

m_i- _,__ , Cylinder size, 4' x 8'

v - |,'__ _',,,, ..__ Pwer_ge Curve(/)_: - ,,

I.,.I- _ ', ,,n'e__ , .,l--

";I .....-""'-, I I I I i /..... I I I I I.00 .01 .0;:) .03 .04 .05 .06

STRAIN

Fig. A.38 - Stress vs. Strain Response of A2%S3P0.75,3 Days, 4"x 8" Cylinders

206

o5


r_ HybPId HIx

,,,, 3/4' Polypr,opytene +q)--

,,"_ ', 30/50 Hooked Fiber,s, VF = 2_.t" t_

__ , Cylinder` size, 4' x 8'

"-" / "_,:_., _ Average Cur,ve(/) _: ',4

ry _ :; ', ',II t. #.

iI

I ! I I 1 I / ..... r_-:-I I 1.00 .0! .02 .03 .04 .05 .06

STRAIH

Fig. A.39 - Stressvs.StrainResponseof A2%S3P0.75,7 Days,4"x 8" Cylinders

if FRC - Test a't 28 da';.JS

Hybrid HIx

3/4' Pot_jpropytene +

"Dr"[_ _'l_" 30/50 Hooked Fiber,s, VF = PZ}u5!'- _ C_jtOndersize, 4' x S'

_ , _ _ Aver'aoeCur,ve(,,,)

_ r6 '""

.00 .OI ,02 .03 .04 .05 .06

STRAIFI

Fig.A.40 - Stressvs. StrainResponseof A2%S3P0.75,28 Days,4"x 8" Cylinders

207

cOm

F'RC - Tes4; aLt: I d_t,j

r(- I.a'tex HIx

- 50/50 Hooked $'t:ee| Fibers

,_- VF = I?.

i- Cylinder size, 4' < 8'

I- ,"_" Avera.eCurve

° s.

,.,

.00 .01 ,OP ,03 .04 .05 ,06

STRAIM

Fig. A.41 - Stress vs. Strain Response of B1%S5,1 Day,, 4"x 8" Cylinders

°

_f F'RC - Tes't QI: 3 days

LQ'tex HIx

50,,'_0 Hooked S'teet Fibers

VF = l?.

U') Ct,jtlnder slzet 4" x 8"AverQge Curve

-'2"

t _ I I I I I I ,! I I.00 .01 .02 .03 .04 .05 .06

STRAIDI

Fig. A.42 - Stress vs. Strain Response of B1%S5,3 Days, 4"x 8" Cylinders

208

.- FRC - Tes_ _ ? dQys- Latex HIx- 50/50 Hooked $_ee| Fibers- VF = 17.

I I I I I I I I I I I

.00 .01 .02 ,03 .04 .05 .06

STRAIM

Fig. A.43 . Stress vs. Strain Response ofBl%S$, 7 Days, 4"x 8" Cylinders

°

GO

FRC - Tes_ a_ 88 d_ysr_ . Latex HIx

50/50 Hooked Steer Fibers

._ _ ,, ,, Cylinder size, 4' x 8'V _ 1

•, AverQge Curve

r_F ,,,, ,,(/) _,Ld " ', "£v _I--

..'-'-.'-'.-.-- ......

.00 .01 .OE ,03 ,04 .05 .06

STRAIM

Fig. A.44 - Stressvs. StrainResponseof B1%SS, 28 Days,4"x 8" Cylinders

209

co

FRC - Test at 1 day- Latex Mix

- 1/2' Potypropytene Fibers"_- VF = IZ

__ Irii Cylinder size, 4" x 8'

) - Average CurveB

.00 .01 .OE .03 .04 .05 .06

STRAIN

Fig. A.45 - Stress vs. Strain Response of Bl%P0.5,1 Day, 4"x 8" Cylinders

m

FRC - Test at 3 daysr_ m Latex Mix

1/2' Potyprop_j|ene Fibers,,6- VF : 1_.

i-iri CI,j|lnder size, 4' x 8'

r- ,-, Average Curve

+i- ih_

<"<,il-f ,_,,,

,00 .or .02 ,03 ,04 .05 .06

STRAIPI

Fig. A.46 - Stress vs. Strain Response ofBl%P0.5,3 Days, 4"x 8" Cylinders

210

0o

F'RC- Test _t 7 d,,ysr_- LQ'tex HIx

- 1/2' Potypr'opytene F'lber,s"0 - Vf' = 1_

Ul.._ _ - ,', Cy|lhder size, 4' x 8'v " ' Aver,age Curve

F-

i l I I I I I I I I I.00 .01 .08 .03 .04 .05 .0(=

STRAIH

Fig. A.47 - Stress vs. Strain Response of Bl%P0.5,7 Days, 4"x 8" Cylinders

f IrRC - Test at 28 daysI< Latex Mix

• 1/2' Polypr'opytene FIber,s;' Vf' = W.

y _ Cylinder` size, 4" x 8'

v Aver'age Curve(_:

L,Jn,'e, iI--

' f I i I I I I I I I I.00 .01 .08 .03 .04 .05 .06

STRAIH

Fig. A.48 - Stress vs. Strain Response of B1%1)0.5,28 Days, 4"x 8" Cylinders

211

cJ

O_- FRC - Test a_: 1 day- Lttex Mix

o_- VF=O

v Cylinder size, 4" x 8"

I I" I.....i....._.....L.... I . I I I I

.00 .01 ,02 .03 ,04 .05 .06

STRAIH

Fig. A.49 - Stress vs. Strain Response of B0%CON, 1 Day, 4"x 8" Cylinders

D

o_- f'RC - Tes_c _t 3 d_js- Lo'tex Mix

o6- VF=0

I ,v. oo.

ai ,,'

,00 ,01 ,02 ,03 ,04 ,05 ,06

STRAIH

Fig. A.50 - Stress vs. Strain ResponseofB0%CON, 3 Days, 4"x 8" Cylinders

212

c_m

o_ - FRC - Test Qt 7 d=ys- Latex Nix

(_- VF=O

I_ -_ _ it

v Cylinder size, 4' x 8'/

V) ui ',, Average(_) le#iJl

LIJ lit.

nt_I--_'_i ,

F

i I I I I I I I I I I.00 .01 .02 .03 .04 .05 .06

STRAIM

Fig. A.51 - Stress vs. Strain Response ofB0%CON, 7 Days, 4"x 8" Cylinders

B

o_ FRC - Test at ;)8 dQ_js

, LQ_cex Mixo_ /j VF=0

r< _'__i Cylinder size, 4' x 8"

(_ ui / _ AverQge,

iiI.

It

P !

I '_ I I I I I I I I I I.00 .01 .02 .03 .04 .05 .06

STRAIH

Fig. A.52 - Stressvs.Strain Responseof B0%CON, 28 Days, 4"x 8" Cylinders

213

a_

FRC - Test Qt ! dayr_- SltlcQ Fume Mix

- 50/50 Hooked Fibers

- VF = I_.m l_

tn _',."',.__ _ /,, _',, Cytlnder size, 4' >: 8'v ____ Average Curve

(/)

L_rv ',_'

g-I

1 I I I I I.00 .01 .02 .03 ,04 .05 .06

STRAIH

Fig. A.53 - Stress vs. Strain Response of C1%$5,1 Day, 4"x 8" Cylinders

a_

_f FRC - Test (st 3 days

SILica Fume HIx

- 50/50 Hooked Fibersi ! I L

I-i'l,_ _. c_.,,dors,-e,4' ,_e'1-:It _... __ AveraQeCurv,

.00 .01 .02 .03 .04 .05 .06

STRAIM

Fig. A.54 - Stressvs. StrainResponseof C1%$5,3 Days,4"x 8" Cylinders

214

/

-_ FRC - Tes_ a_ ? dG_jsoo. ,", SI(Ic_ Fume HIx

"f /_'li_/" 50/50VF= 17.Ho°ked Fibers

r_

,- "F il/ :',,, C_t.,,ders.-e.4'x ."_1- :i_ ,_ __ Aver,OeCurve

)I/ \_ : .!'! I; y

_(_ t") 'l '-"

-- _ir i i I I 1,I I I I I I

.00 .01 .02 .03 .04 .05 .06

STRAIM

Fig. A.55 - Stress vs. Strain Response of C1%$5,7 Days, 4"x 8" Cylinders

o_

o_ FRC - Tes_c _ 28 days$1llc:a Fume Mix

50/50 Hooked FibersVF = 1;':.

j-%

__ Cylinder size, 4' x 8'

v Ui Average Curve_q_qLd_n¢

II _4.

.00 .01 .02 .03 .04 .05 .06

STRAIH

Fig. A.56 - Stress vs. Strain Response of C1%$5,28 Days, 4"x 8" Cylinders

215

a_

- FRC - Tes_¢_t; I dc_yr_ - SItlca Fume HIx

- 3/4' Polypropytene Fiber's

u'i - Cytlnder-size, 4" x 8"- -_ Aver-Qge Curve

FiAi '

. I I

.00 .0! .02 .03 .04 .05 .06

STRAIH

Fig. A.57 - Stress vs. Strain Response of C1%P0.75,1 Day, 4"x 8" Cylinders

.

_t FRC - Tese _¢ 3 days_;Itlce Fume HIx

3/4' Potypropytene Fibers

tn ,:_y _- ,,_* C_jtlndeP size, 4' x 8'v - '_ Averoge Cur.re

(/J

,.,-ry __ r,l,l,,J,-, '

(/') -i ' 'I

I I "f'" I I I I I I I I

.00 .0! .02 .03 .04 .05 .06

STRAIH

Fig. A.58 - Stress vs. Strain Response of C1%P0."15,3 Days, 4"x 8" Cylinders

216

0_

F'RC- Tes'l: o_ ;' doysr_ SILica Ful_e Hlx

3/4' PoL_jprop_tenePlbersVF = l?.

tn__ u_ Cytlnder size, 4' x 8'v _ Average Curve

",, _q ,q..

.00 .01 .02 .03 .04 ,05 .06

STRAIN

Fig. A.59 - Stress vs. Strain Response of C1%P0.75, "7Days, 4"x 8" Cylinders

F.RC- Tesl: at: P8 daysSilica F.umeHIx

,' I/2' Potypr'op_tene F.ibersVf = 17.

tny u'J . CyLinder"size, 4' x 8'v , Average Curve

I

(_L,.I ',I---

.00 .Ol .OP .03 .04 .05 .06

STRAIN

Fig. A.60 - Stress vs. Strain Response of C1%P0.5,28 Days, 4"x 8" Cylinders

217

FRC - Test at 1 dayrK-

._;l|lca FuMe Hybrid Mix- :]0/50 + 50/50 Hooked Fibers- VF = IZ

f%,°I

IP _ '_ C_jtlnder size, 4" x 8'"J '_, Average Curve

(/)

._

I I I I I I I I 1 I I•00 .01 .02 .03 ,04 .05 .06

STRAIH

Fig. A.61 - Stress vs. Strain Response of CI%S3SS, 1 Day, 4"x 8" Cylinders

f FRC - Test at 3 d_t,jsr( $1LIcQFume Hybrid HIx

30/50 + 50/50 Hooked Fiberso

,,D Vt" = 1_.it f I

__ I_ C_j|lnder size, 4" x 8"'_' I,' _'_e',, _ Average Curve

" i! I _t I t

I I. I

°

I I I I I ""1" I I I I I,00 .01 .0_ ,03 .04 .05 .06

STRAIH

Fig. A.62 - Stressvs. Strain Responseof C1%$3S$, 3 Days, 4"x 8" Cylinders

218

tlf t

FRC - Test Qt 7 d_ys

r_ SILIcG Fume Hybrid HIx

, 30/50 + 50/50 Hooked Fibers

" VF = W.

I ui ,, CyLinder size, 4' x 8'V

,, Average Curve

Ld l -n¢ _i ° ,, ,.I-- '

.00 ,01 .02 .03 .04 .05 .06

STRATN

Fig. A.63 - Stress vs. Strain Response of C1%$3S5,7 Days, 4"x 8" Cylinders

oo "i. - '-.' IrRC - Test at 28 d_gs

I_- _I_ Sitlc_ Fume H_jbrld Hlx

. - li_ , 30/50 + 50/50 Hooked Fibers

ul - ,, C_jtlnder" sizes 4' x 8'

- i_t', Average Curve

!\

(_ _: ,, ",,

N l ', , "..

.00 .01 .02 .03 .04 .05 .06

STRAIM

Fig.A._;- Stressvs.StrainResponseofCI%$3S5,:38Days,4"x8"Cylinders

219

OD

FRC - Test Qt I d_yr_-ControlMlx

- Cgtlnderslze,6' × 12'

I_- AverQge Curveii

,}. f I

l; I LLd ',,nt _,i-i_" f E0'1 ,

I ; ii_ "J I I f

JI;I

"I l I l I I I I I l l,00 .01 ,02 ,03 ,04 .05 ,06

STRAIN

Fig. A.65 - Stress vs. Strain Response of Control Mix, 1 Day, 6"x 12" Cylinders

°J LL FRC - Test =t I dcxt,j

r_ L 30/50 Hooked Fiber's, L/d=60

.[- VF = 1_.( oF Concrete)

_OF ,', Cylinder size, 6' x 12'

_ ___i__L' Aver'Goe CUrVe

.00 .01 .0;_ .03 .04 .05 .06

STRAIH

Fig. A.66 - Stress vs. Strain Response of A1%S3, 1 Day, 6"x 12" Cylinders

220

cd

FRC - Test (;± I d_y

i_- 30/50 Hooked Fibers, L/d=60- Vf = 27. ( oT" Concrete)

- Cytlnder size, 6' x 12'

__ ui- ," AverQge Curve

f• t

.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig.A.67- Stressvs.StrainResponseofA2%S3,1 Day,6"x12"Cylinders

_f FRC - Test 0"¢I doL_J

50/50 Hooked Fibers, t/d=100Ve" = 17. (oF Concrete)

2, C_jUndersize, 6' x IP'm /

i ,l I

i

M f

.00 .01 .0P .03 .04 .05 .06

STRAIIH

Fig. A.68 - Stress vs. Strain Response of A1%S$, 1 Day, 6"x 12" Cylinders

221

co

.- F'RC - Test Qt I d,,yr%. - i

3/4 Poh,jpropytene Fibers

- VF = I_.(oF Concrete)

- CyLinder size, 6' x 12'

u_ - - Average Curve

\."'1 I I I I I I I _

.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. A.69 - Stress vs. Strain Response of AI%P0.75, ! Day, 6"x 12" Cylinders

o_I

FRC - Test Qt 1, day

K- 3/4' Polypropytene Fibers

- VF = 2_. (oF Concrete)

-- Cylinder size, 6' x 12'

.._. _ - _--AverQge Curve

.00 .01 .0;_ .03 .04 .05 .06

STRAIH

Fig. A.70 . Stressvs. StrainResponseof A2%P0.75,1 Day,6"x 12" Cylinders

222

FRC - Tes_ Q_ I dayr_- Hybrid HIx

- 30/50 + 50/50 Hooked Fibers" VF = 1% ( oF Concrete)

i u_- CyUnder slze,6' x 12'v _ Average Curve

(/)_ _: -_,:__

Ld

- I I I I J.00 .01 .02 .03 .04 .05 ,06

STRAIN

Fig. A.71 - Stress vs. Strain Response of A1%$3S$, 1 Day, 6"x 12" Cylinders

o6

FRC - Tes_ a_ I dayI_- Hybrid Mix

- 30/50 + 50/50 Hooked Fibers

- VF = 2_ ( oF Concrete)

.._ u_ __"L ,, C_ltlnder size, 6" x 12"

_' Average Curve

V)bJIZt_ -, ,.,

-. t-•

I i I I I I I I I I I.00 .01 .02 .03 .04 .05 .06

STRAIH

Fig. A.72 - Stress vs. Strain Response of A2%S3S5,1 Day, 6"x 12" Cylinders

223

0oI

FRC - Test at I day

r_- Hybrid HIx

3/4' Potypropgtene +

- 30/50 Hooked F'lbers, VF = 1_.

.._ I_ Cy|lnder size, 6" x 12'

v _ __ Average Curve

_,_-

,00 ,01 ,02 .03 .04 ,05 .06

STRAIH

Fig. A.73 - Stress vs. Strain Response of AI%S3P0.75,1 Day, 6"x 12" Cylinders

0o

FRC - Test at I day

- Hybrid H1xm

3/4' Polypropgtene +

- 30/50 Hooked Fibers, V£ = 2_.

.._ _ Cytlnder size, 6' x 12'

- AverQge Curve_1: -

.00 .01 .0;_ .03 .04 .05 .06

8TRAIH

Fig. A.74 - Stress vs. StrainResponseof A2%S3P0.75,1 Day,6"x 12" Cylinders

224

00

reC - Test ot 1 d_j- Lo_ex Hlx

- 50/50 Hooked Steer Fibers

- VP = 17.

__ I_- Cy|lnder size, 6' x 12'v _ Averoge Curve

t tt •

t te t.

ai . ....

,00 ,01 .02 .03 .04 .05 .06

STRAIN

Fig. A.75 - Stress vs. Strain Response ofBl%S5,1 Day, 6"x 12" Cylinders

o

a}m

FRC - Test at I da_j- L_tex Mix

- Id2° Pol_jpropgtene Fibers

- VF = W.

_C ui - CyLinder size, 6 ° x 12"v _ _ Averoge Curve

•00 .01 .08 .03 ,04 .05 ,06

STRAIN

Fig.A.76- Stressvs.StrainResponseofB1%P0.S,IDay,6"x12"Cylinders

225

=Ln

FRC - Test _t 1 dayI_ SI[IcG Fume Mix

50/50 Hooked Fibers.

_o VF = t?.

mui (,',_, Cytlnder size, 6' x 12'

v '=_,/_. ___ Average Curve

I*t IlIit r . i

t • / t', "t _.

_ "l s_¢ L',•¢l"

I J I I I I I, I I I I,00 ,01 ,02 .03 .04 .05 ,06

STRAIN

Fig. A.77 - Stress vs. Strain Response of C I % $5,1 Day, 6"x 12" Cylinders

ooB

FRC - Test at I ,:Jayr< i- Sltlc= Fume Mix

- 3/4' Potypropytene Fibers- Vf = IX

p%

ui- C_jtlnder size, 6' x 12'v _ Average Curve

LJnte_

t

I I [ ..... I I .... 1.... _4 t I I I,00 ,Ot ,OP ,03 ,04 .05 ,06

STRAIN

Fig. A.78 - Stress vs. Strain Response of CI%P0.7S, 1 Day, 6"x 12" Cylinders

226

ao

F'RC - Tes't o,t I day

I'_- SILica Fune Hybrid Mtx- 30/50 + 50/50 Hooked F'tbers

- VF = W,

U'l Ir)- C_Llnder SlZe_ 6' x |E'

v - f_,, AverQge Curve

.00 .01 .08 .03 .04 .05 .06

STRAIH

Fig. A.79 - Stress vs. Strain Response of C1%$3S$, I Day, 6"x 12" Cylinders

227

05

FROl - Tesl ot 1,3,7.and 2B days

- HybridHlx- 2/'I'PotypropyLene+

_6- 30/50 Hooked Flber:s,V? = 1%

slze_ 4' x B'u5 Cylinder"

•,..,' F )_'_, ____ I doy

................3 d ys

oJFII_. \\ 'L"'..

I I " I I I 1 I I,00 ,01 ,02 03 ,04 ,05 ,06

STRAIN

Fig. A.80 - Stress vs. Strain Response of Mix AI %S3P0.5 with Time

05

FRC - Tes± a± 1 dog

- Hybrid Nix

- 2/4' Polypropylene+- 30/50 Hooked Fiber's,V? = 1Z

U% u_ - Cgtlnder slze, 4' x B' and 6' x 12'iv _ 4' x 8'

(,.,)_ _ - --- 6' x IP'0")w

I I I I..... I I I I I I I.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. A.81 - Effect of Cylinder Size on the Stress-Strain Response of Mix AI%S3P0.5

228

o5 | FRC - Test et 1,3,7, end 28 dQys

_- Hybrid HIx

. F Z/4' Potypropytene + ._0r- iN= 30/50 Hooked Fibers, VF = 2X.

.| lii -\ ,I d=u

.00 .01 .0P .03 .04 .05 .06

STRAIN

Fig. A.82. Stress vs. Strain Response of Mix A2%S3P0.5 with Time

o6

FRC - Test ot: 1 day

=- Hybrid HIx- 2/4' Potypropytene Fibers +- 30/50 Hooked Fibers, VF = 27.

_- Cylinder size, 4' x 8' and 6' x 12'Yv 4' x 8'

(/J _ 6' x 12'£/)bJ

n,'(_

(/) "k

°

' I _ _ I "1.... T--- I I I i I.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. A.83 - Effectof CylinderSizeontheStress-StrainResponseofMix A2%S3P0.5

229

.00 .01 ,02 .03 .04 .05 .06

STRAIH

Fig. A.84 - Stress vs. Strain Response of Mix B0%CON with Time

230

o';_| Test (_t 1,3,7, and ;)8 days

o_f L(lt;ex Mix

50,/50 Hooked Steer Fibers

r_ VF = 1_.

Cytlnder size, 4" x 8"

.I- -[- _ ..........3d°_,"E id-';'_.., ---_d°_s

.00 .OI .02 .03 .04 .05 .06

STRAIN

Fig. A.85 - Stressvs.Strain Responseof Mix B1%S5 with Time

FRC - Test at I dot.jr<- L(x_cex HIx

- 50/'50 Hooked $_ee| Fibers- VF = IZ

m.._ ui- Cytlnder size, 4' x 8' (xnd 6' x |2'v __ 4' x 8'

(/) q: 6' x 1@"(/3Ldn,'c, ii-

I I I I I I.00 .0! ,0;) .03 .04 .05 .06

STRAII'I

Fig. A.86 - Effect of Cylinder Size on the Stress-Strain Response of Mix B1%S5

231

o_

0o i F'RC - Tes¢ =t: 1o3,7., Qnd ;)8 days_ L_t.ex HIx

r_- 1/2' Po|ypropylene F'lbePs

__ _- Vf = IXA Cytinder size, 4 x8'|

F__-:/_"??, _-2. day,

.00 .01 .OP ,03 .04 .05 .06

STRAIM

Fig. A.87 - Stress vs. Strain Response of Mix BI%PO.5 with Time

_- FRC - Tes_ Q_ I doy- Lo_ex Mix

- 1/2' Po|ypr'opy|ene f'lber-s

v____ Cytlnder- size, 4' x 8" ¢md 6' x |;_'- _ 4' x 8"

E'_/V I "_'__! I I I I I I

,,,4

.00 .01 .OP .03 .04 .05 .06

STRAIM

Fig. A.88 - Effect of Cylinder Size on the Stress-Strain Response of Mix B1%P0.5

232

FRC - Test Qt 1.3.7, Gnd 28 dQysmSilica Fume HIx

IX. 50/50 Hooked Fibers

,-, VF = IX

.Xv v) Cylinder slze_ 4' x 8'

t

(/I I d_y

Ld _ - _"'-,.... .............3 daysf,y _ -

• "'""'" - - -7 d_ys• "'-.

C/) _ - "',, "............ • 28 days

• --...°._ °...

.00 .01 ,02 .03 .04 .05 .06

STRAIM

Fig. A.89 - Stress vs. Strain Response of Mix CI%SS with Time

I

FRC - Test at I day_:-SII.IcO. Fume HIx

50/50 Hooked Fibers

_6 - VF = W.._ p

.._ u') Cgllnder slzea 4" x 8' (lnd 6' x 12"v ' _ 4' x 8'

V) _: . - - -6" x 12'

(/) ''_'t.i.i

n,e_ ,-

I

!

' I I I I I I I I I I I.00 .01 .02 .03 .04 .05 .06

STRAIN

Fig. A.90 - Effect of Cylinder Size on the Stress.Strain Response of Mix C1%$5

233

o_

FR[" - Test at 1,3,7,_nd 28 dnys

oo- SILIcn FuMe HIx

I/2' PoLypropytene FibersIx.- VF = 1X

i Cylinder stze_4' x 8'---- I day

v uo 3 days

t. .... 7 daysb.I _rY _- , E8 days

_M

----.,.

I I I I I I I I i I I.00 .01 .02 .03 .04 .05 .06

STRAIM

Fig. A.91 - Stress vs. Strain Response of Mix CI%P0.5 with Time

o_D

FRC - Test =t 1 d=9D SILIc_ Fu_e HIx

- 3/4' Polypropylene Fibers- V_ = 1X

u_- CyLinder size, 4' x 8' _nd 6' x 12'Yv _ 4" x 8'

(/) _ D . -- -- --6" X 12'(/) 't

1

°

I I I I I I I I I I I,00 ,01 ,02 .03 ,04 .05 .06

STRAIH

Fig. A.92 - Effect of Cylinder Size on the Stress-Strain Response of Mix C1%P0.5

234

f FRC - Tes'¢ e_ L3,7, _nd 28 d_jsSitlce Fune H_jbrld HIx

} jt:, 4x._I" fA _"i:, __I d.,

"1:///t,",,, ---'"o_,

,:" "',. ,,..

,00 ,01 ,0_ ,03 .04 .05 .06

STRAIM

Fig. A.93 - Stress vs. Strain Response of Mix C1%$3S5 with Time

06w

FRC - Test ot I da MK

Silica FuMe Hgbrld HIx

30/50 + 50150 Hooked FlbePs

VF = 17.

u_ C_jllndeP slze_ 4' x 8" and 6" x IP"

_: - --6'x '

I I I I I I 1 1 I I !

.00 .01 .02 .03 .04 .05 .06

STRAIM

Fig. A.94 - Effect of Cylinder Size on the Stress-Strain Response of Mix C1%$3S5

235

oo

FRC - Test 61 ! d=yr< Conparo1:Ive Ev_tuQ1:lon

oi: DiFFerent: Mlxes_6- .."-'... V¢ = EX

j-%

"-'L/_In- / "... C.bj{Inder slze_ 4' x 8'- / : 30/50 Hooked St:eeL

(/_ _ _ i --_ 1/2' Potqpropqtene

ai

"'"'-......

i._ | |o' i , , , [.......... .....

STRAIN

Fig.A.95- EffectofFiberTypeontheIDay Stress-StrainResponse(Vf=2%)

o6

- "_:'%:. FRC - Test: Q1:28 d=qs

r_- f "".. Compara1:lve Evatua1:lon- i \ o¢ 111FFeren1: Mixes

',6- - '" VF = :_X . ,

v_u5- i :" Cqtlnder" size, 4 x 8

_._ i A '.. 30?0 Hooked St:eet

.00 .01 .OP .03 .04 .05 .06

STRAIH

Fig. A.96 - Effect of Fiber Type on the 28 Day Stress-Strain Response (Vf=2%)

236

°°LL FRC - Test at I d_H

r([ ComparQtlve Evatua¢lon

. F oF ])lFFerent Mixes

_ _t- H".._",,\ C_,.,,de,-s.ze.4'xF _'";i',\ --30/50 Hooke'`S_eet_-li -_;':_ ..............50/50Hook,'s̀_eeL

_' I-li ::;_. - - -30/50.50/50Hook..,Stee,.11:1_ '-% . 30/50Hookednher-s .

m r-I,L I '.._,I'-I_" _ ;'_' 1/2" Potyprop_jtene

• L,

t-/l \

,00 .01 .02 .03 ,04 .05 ,06

STRAIH

Fig. A.97 - Effect of Using2 Types of Fiber on the I Day Response(Vf=1%)

a_

FRC - Tes± Q¢ 1 d_yP_ Comparative Ev_tua_clon

. oF ])lFFeren¢ Hlxes

_o (/_ VF = 27,, \Ul

CytlndeP size, 4' x,,,uS 8'

v /', "_ __ 30/50 Hooked Steel(/) _ / _ \ ..............30/50 + 50/50 Hooked Steer

OO / ', _ - - -30/50 Hooked sleetbJ

/ .."_))_. _ + 1/2' Polypropytenenl _I-- ,:" _'-..

o.i

I I t t _ t I I l I ],00 .01 .02 ,03 ,04 .05 .06

STRAIH

Fig. A.98 - Effect of Using 2 Types of Fiber on the 1 Day Response (Vf=2%)

237

.

F'RC - Test _t ! da_j- ConparQtlve EvatuQtlon- 50/50 Hooked Steel F.Ibers

-F£. r

L# 1 _t_.::, ............ F'RC + LatexI_Wpi ..o,f_ [-_ 1 _, . Control + L,tex

.00 .0! .08 .03 .04 .05 .06

STRAIM

Fig. A.99 - Effect of Latex and Silica Fume on the 1 Day Stress-Strain Responseof the 50/50 Mix (Vf=l%)

F.RC - Test ot I dagr%Comparative EvaLuationPottjpropyiene F.Ibers

in._ IfJ CyLinder" slzel 4' x 8'V

-- PLain F'RC

GO - - -FRC + SIIIco FumeI.I _,'T'rY ei • -_ ................J:RC + L_tex

GO . _ : Control + L_tex

oJ

.00 .01 .02 .03 .04 .05 .06STRAIM

Fig. A.100 - Effect of Latex and Silica Fume on the 1 Day Stress-Strain Responseof the Polypropylene Mix (Vf=l%)

238

f FRC - Test at 1 deyComparative Evatu,,tlon (Hybrid HIx30/50 + 50/50 Hooked Steel

.l'- ",'X Sil=ar,,.e

.00 .01 .02 .03 .04 .05 .06

STRAIH

Fig.A.101 - Effectof SilicaFumeonthe1Day Stress-StrainResponseof the 30/50 + 50/50 Mix (Vf=1%)

- '°' F'RC - Test at P8 days

o0E /_\ Col_par_tlveEva[uatlon:_1 _ 50/50 Hooked Steel F'lber's

: ',.-...

'::LI i I k ""................. IrRC + Latex

03

.00 .01 .02 .03 .04 .05 ,06

STRAIH

Fig. A.]02 - Effect of Latex and Silica Fume on the 28 Day Stress-Strain Responseof the 50/50 Mix (Vf=1%)

239

(5


r_ - Conp_r_tlvervQtua,t10nPoigpropyieneFibers

; VF = W.;t .

°_ ; --

I_ Cgtlnder slze_ 4' x 8"Plain FRC

:',iC,_ - - -F'RC + SI[Ic(I F'ul,le

: t

I-'- _ _ ...............JrRC �L_'texC,q - .:.._ ,, Con'trot + L_tex

03- ,.

i i I i I I i i i t i.00 .01 .0P .03 .04 .05 .06

STRAIH

Fig.A.103 - Effect of Latex and Silica Fume on the 28 Day Strew-Strain Responseof the Polypropylene Mix ('Vf=1%)

.00 .01 .0_ .03 ,04 .05 .06

STRAIH

Fig. A.104 - Effect or Silica Fume on the 28 Day Stress-Strain Responseof the 30/50 + 50/50 Mix 0/r=1%)

240

8A

¢¢¢¢

in

(n 5 ---"_-

d 4

3Type of Fibers: 30/50 Hooked Steel

2 -- _-- Controlo Vf = 1%

1 - Vf = 2%

! ! ! I

1 3 7 28

Time, days

Fig. A.105 - Compressive Strength, f'c vs. Time, 30/50 Steel Fibers

8

=,=,_ ,== ,_, ==, 4_ _ _ _ _ _ _ m m _1_

6

•_ 5 ....

"" 3 Type of Fibers:3/4" Polypropylene Fibers

2 --_-- Controlo , Vf= 1%

1 - Vf = 2%

I I I l

1 3 7 28

Time, days

Fig. A.106 - Compressive Strength, f'c vs. Time, 3/4" Polypropylene Fibers

241

8

7

6

mDw_

UD --

Type of Fibers:2 30/50 + 50/50 Hooked Steel

---'*'-" Control1 . o Vf=1%

= Vf = 2%I ! ! !

1 3 7 28

Time, days

Fig. A.107 - Compressive Strength, f'c vs. Time, 30/50 - 50/50 Steel Fibers

8

J

4

Type of Fibers:;-" 3 30/50 Hooked Steel +

2 3/4" Polypropylene Fibers---x-- D Control

1 0 Vf = 1%= Vf = 2%

O I I I I

1 3 7 28

Tlme, days

Fig. A.108 - Compressive Strength, f'c vs. Time, 30/50 Steel + 3/4" Polypropylene Fibers

242

9

7 .,.,.....,....'tP

6

Chemical Additive: Latex

"- 3 Vf = 1%

2 -- _-- Controlo 50/50

1 -- Polypropylene* Control + Latex

I I I I

1 3 7 28

Time, days

Fig. A.109 - Compressive Strength, f'c vs. Time, Latex, (Vf=1%)

9

8

7 41" ----41_

.___.,_64'*"fJ _ Chemical Additive: Silica Fume

3 Vf = 1%

-- _-- Control2 _ 50/50

1 -----a---- Polypropylene-'- 30/50 + 50/50

! I I ] l

1 3 7 28Time, days

Fig. A.110 - Compressive Strength, f'c vs. Time, Silica Fume, (Vf=l%)

243

7

• `* _' _lf" _ _w

6im

u)._¢ 5 ....

¢; 4'_. Type of Fibers:

30/50 + 50/50 Hooked Steel3Vf = 1%

2 --_-" Controlo , Plain FRC

1 -- ' Silica Fume Modified FRC

I I I I

1 3 7 28

Time, days

Fig. A.111 - Compressive Strength, fc vs. Time, 30/50 + 50/50 Steel Fibers, (Vf=l%)

244

7000

ooo5000

•-_ 4000

GuJ 3000 Type of Fibers:

30/50 Hooked Steel

2000 --_-- ControlVf= 1%

1000 ¢ Vf = 2%

I I l I

1 3 7 28

Time, days

Fig. A.112 - Elastic Modulus, Ec vs.Time, 30/50 Steel Fibers

5O0O

4500

4000 ........

3500

"- __' 3000 _- ____

m n=

o" 2500IJJ

2000 Type of Fibers:3/4" Polypropylene Fibers

1500-- "_-- Control

1000 --,-o--. Vf = 1%Vf = 2%

5OO

i | ! !

1 3 7 28

Time, days

Fig. A.113 - Elastic Modulus, Ee vs.Time, 3/4" Polypropylene Fibers

245

5OOO

45OO

4000 x- u-......... . - _

•_ 3000

G 25oo/ Type of Fibers:

uJ 2000 / 30/50 Hooked Steel +1500 i" 3/4" Polypropylene Fibers

1000 -- _-- ControlVf= 1%

500 = Vf = 2%

0 , , , , I1 3 7 28

Time, clays

Fig. A.114 - Elastic Modulus, Ec vs. Time, 30/50 Steel + 3/4" Polypropylene Fibers

5O0O

4500

4000 x-........ u- ........ _- ...... _O

-3000

tS 2500ill

2000 Type of Fibers::30150 + 50150 Hooked Steel

1500--"_--- Control

1000 Vf = 1%-- Vf = 2%5OO

I I I I

1 3 7 28

Time, days

Fig. A.II5 - Elastic Modulus, Ec vs.Time, 30/50 + 50/50 Steel Fibers

246

I

8OOO

7000 Chemical Additive: Latex

6000 Vf = 1%

50OOmm

U'}

r_ 4000 x- 41(IJ,I

3000

2000 --"_'-- Control (Plain Concrete)50/50

1000 ; Polypropylene•J- Control + Latex

I I i l

1 3 7 28

Time, clays

Fig. A.II6 - Elastic Modulus, Ec vs. Time, Latex, (Vf=1%)

5OOO

4500

4000 --'_" ....

35OOm

,.¢ 3000

G 2500IJJ

2000Chemical Additive: Silica Fume

1500 Vf = 1% __.._._. Control1000 o 50/50

-- Polypropylene500 A 30/50 + 50/50

I I I I

1 3 7 28

Time, days

Fig. A.II7-ElasticModulus, Ec vs. Time, Silica Fume,(Vf=l%)

247

8000 1 --"_'-" Control /m7000 --o--- Plain FRC /

6000 1 Latex Modified FRC /

_ 5000t• A S lica Fume Modified FRO /

t ,1002 ] =

1 3 7 28

Time, days

Fig. A.118 - Elastic Modulus, Ec vs.Time, 50/50 Steel Fibers, (Vf=l%)

7000

Type of Fibers: Polypr0pylene6000 Vf = 1%

5000=me=

x- _- ........ _._4000 - - - ._

¢;uJ 3000

2000 ---=--- ControlPlain FRC

1000 " Latex Modified FRC-'- Silica Fume ModifiedFRC

01 3 7 28

Time, days

Fig. A.II9 - Elastic Modulus, Ec vs. Time, Polypropylene Fibers, (Vf=1%)

248

5000

4500

35004000 _ ........•_ 3000

2500o" Type of Fibers:u,I 2000 30/50 + 50/50 Hooked Steel

1500 Vf = 1%

1000 ---m--- ControlPlain FRC

500 -- Silica Fume ModifiedFRC

01 3 7 28

Time, days

Fig. A.120 - Elastic Modulus, Ec vs. Time, 30/50 + 50/50 Steel Fibers, (Vf=1%)

249

Appendix B

Bending and Tensile Tests

Table B.1 : Strength Results for each Individual Specimen.

Fig. B.1 - B.16: Graphs of Load versus Deflection and Strain Capacity Response

with Time.

Fig. B.17 - B.20: Load versus Deflection Response for Different Series.

Fig. B.21 - B.29: Modulus of Rupture fr.

Fig. B.30 - B.39: Toughness Indices.

251

Table B.1. Detailed fc, fr, and fspt Data

Mix ID Specimen fr fc ,_sptID (psi) (ksi) (_si)

Control t 1D_I 637.5 4.22 517.25Control 1i3_2 .... 656.25 --- 298.42 ....Control "iD AV '_ 646.88 ..... 4.22 - 407.83 'Control 1D_I 600.0 ......_ontr0i _D_2 ...... --- _--

_.ontrol 7D AV 600.0 "--- ......... ---_ontrol 28D_1 712.5 ......Cgntrol ..28D 2 ......... 868.13 ......Control 28D AV 790.31 --- ".... ---A1%S3 1DT 1162.5 ' 3.26 696.3A1%S3 19_2 712.5 --- 795.77)_i %S3 ID AV 937.5 3.26 746.04A1%S3 7D_l 900.0 ......A1%S3 'lD_2 910.5 ...... -.....Ai%S3 7D AV ..... 905.25 ...... --....A1%S3 28D_1 1068.75 ......Ai%S3 " ' 28D_2 806.25 ...... "A1%S3 28D AV 937.5 ......A2%S3 1D_I 1612.5 5.73 1014.61A2%S3 1D_2 1477.5 5.93 1034.51A2 %S3 iD AV 1545.0 5.83 _' 1024.56A2%S3 7D_-1 1882.5 ......_2%S3 7D_2 i850.63 ...... ' '-A2%S3 7D AV ....1866.56 --- ' ---

IA2%S3 281__1 1567.5 ......

A2%s3 2fl13_2 2068.13 ...... .......A2%S3 28D.AV _ 1817.81 ...... ....


252

Table B.1. Detailed fc, fr, and fspt Data; continued

Mix ID Specimen fr fc fsptID (psi) (ksi) (psi)

A1%S5 1D_I 1271.25 4.42 925.09A1%S5 1D_2 = i63i125 ......... 5_16........... 835.56 .....A1%S5 .... iD AV 145L25 4.79 880.33A1%S5 7D-_l 1575.0 ......A1%S5 7D_2 ........._.1%S5 71) AV 1575.0 ......A1%S5 281__1 1875.0 ......A1%S5 28D_2 ..... i4'62.0 --- ' ---A1 _S5 .... 28D AV 1668.75 ......

A0.15%P0.5 1D=I 564.38 ............ 3:63 ........ 448.02 ....A0.15%P0.5 1D_2 510.0 4.7 472.69_,0,15%P0,5 iD'AV 537.19 4.16 ...... 460.36

A0.15%P0.5 7D1 750.0 ..... -.....K0:i5%P0.5 7D_2 825.0 ......A0.i5%P0.5 7D AV 787.5 ......A0.15%P0.5 28D_1 840 ......A0.15%P0.5 28D_2 ...... 846 ......_0.iS-%P0:5 -- -_28D-AV .......................... 843- --- ---Al%P0.5 1D__ 609.38 3.7 596.83._].%'P0.5 1D 2 ...........678.75 4.46 ........ 660.49_i %'P0.5 ID-AV 644:06 .... 4.08 " 628.66Al%P0.5 _D_1 669.38 ......_1%P0.5 "7D_2 • " 733. i3 --- ...... ---Al%'P0.5 -- 7D AV '70i:25 ......... _ ------ - --:: .....Al%P0.5 28D_1 928.13 ......Al%P0.5 28D_2 948.75 ......_1%P0.5 28D AV 938.44 ......A2%P0.5 1D_I 461.25 2.52 527.2A2%P0.5 1D_2 457.5 ......A2%P0.5 iD AV 459.38 2.52 527.2A2%P0.5 YD_I 658.13 ......A2vo.5 702 581:25 ""iii i-- =:-................A2%P0.5 YD AV ' 619.69 ......A2%P0.5 28D_1 646.88 ......A2%P0.5 2813'_2........ 618.75 _ -_- : --- .............A2%P0.5 28DAV .................. 632.81 ......


253


Mix ID Specimen fr fc _sptID (psi) (ksi) ()si)

A1%S3S5 1D1 1093.13 4.06 716.2A1%S3S5 1D_2 905.63 5.09 580.92 ........Ai %S3S5 ID AV 999.38 4.58 648.56A1%S3S5 7D-1 1518.75 ......A1%S3S5 _D_2 1303.13 ...... -...........A1%S3S5...........7D AV 1410.94 ......Al%S3S5 28D_1 1275.0 ......A1%S__3__S_5.... 2802 1368.75 ......A1%S3S5 Z8D AV 1321.88 ......

A2%S3S5.......... 1D_I .... 1430.63 , , 5.05 ...... ....... 1124.03A2%S3S5 1D_2 1605.0 5.41 966.87A2 %S3S5 ID AV 15i7.81 5.23 1045.45A2%S3S5 rD'l 1800.0 ......A2%S3S5 L7D--2 ' ' 1715.63 ......A2%S3S5 7D AV 1757.81 ......A2%S3S5 28I__1 2118.75 ......A2%S3S5 28D_2 1706.25 ......A2%S3S5 28D AV 1912.5 ...... ...........Al%S3P0.5 1D ]" 600.0 4.46 574.95Ai%S3P0.5 1D_2 695.63 3.98 557.04Ai %S3P0.5 1D AV 647.81 4,22 565.99Al%S3P0.5 7D_1 791.25 ......AI%S3P0.5 70_2 750.0 ......Ai%S3P0.5 7D AV ..... 770.63 ......Al%S3P0.5 28D_1 975.0 ......Al%S3P0.5 28D_2' ' 843.75" ' -.....Ai%S3P0.5 28D AV 909.38 ......A2%S3P0.5 1D_I 562.5 3.58 628.66A2%S3P0.5 1D_2 866.25 3.98 527.2A2%S3P0.5 ID AV 714.38 3.78 577.93A2%S3P0.5 7D_1 838.13 ......A2%S3P05 7D_2 1031.25 ......A2%S3P0.5 7D AV 934.69 -.....A2%S3P0.5 28D_1 1078.13 ......A2% $3P0.5 :28D_2 ......... 1031.25 ......A2%S3P0.5 28D AV 1054.69 --- ........ --- ..............


254



B 1%S5 1D_I 1021.88 3.26 .... 636.62 _B1%S5 1D_2 993.75 2.71 696.3B1-%S5 1D AV ' 1007.81 2.98 666:46B1%85 D_I 1350.0 ......i_1%S5 7D_2 1406.25 ......B1%S5 TD A 1378.13 ......31%S5 28D_lV 1987.5 --- . :--81%S5 28D_2 1856.25 ......B1%S5 28D AV 1921.88 ......B1%P0.5 1D_I 551.25 2.63 318.3181%P0.5 ..... 1D_2 600.0 2.47 .... 33812 .......Bi%P0.5 1D AV 575.63 2.55 328.26B1%P0.5 7D_-1 562.5 ......[31%P0.5 7D.__.2 712.5 --- ---Bl%P0.5 7D AV 637.5 ......B1%P0.5 281_ 1 843.75 ......

"r',

B1%P0.5 28D_2 900.0 ......BI%P0.5 ZSD AV 871.88 ......81%S3S5 1D_T 1068.75 3.5 457.57B1%S3S5 1D_2 958.13 3.66 557.04B1%S3S5 1D AV 1013.44 3.58 507.31B1%S3S5 'D-1 1462.5 ......Bi%S3S5 rD_2 1350.0 --- ........ ---B1%S3S5 7D AV 1406.25 ......

B1%S3S5 28D1 1631.25 -..... •B1%S3S5 28D_2 1875.0 ......

B|%S3S5 Z8D.AV 1753.i3 ......


255



C1%$5 1D_I 1106.25 4.93 827.61C 1%S5 1D_2 1350.0 5.36 89 i.27C1%S5 1D AV 1228.13 5.15 859.44C1%$5 7D 1 1455.0 ......C1%$5 7D_2 i443.75 ......C1%$5 7D AV 1449238 ......C1%$5 28D_1 1706.25 ......C1%$5 28D_2 2250.0 ......C1%S5 28D AV .........i978.13 .... --- ---

C1%P0.5 1D.__ 525.0 3.66 437.68C1%P0.5 1D_2 581.25 3.74 447.62C1%P0.5 iD AV 553.13 3.7 442.65Cl%P0.5 7D_l 641.25 ......01%P0.5 rD_2 656.25 ......C1%P0.5 7D AV .... 648.75 ......21%P0.5 Z8_l 843.75 ......Cl%P0.5 28D_2 731.25 ......C1-%P0.5- 28D AV .......... 787.5 ...... -"-- ---

1

C1%S3S5 1D...1 993.75 4.6 839.54........................ ,

C1%$3S5 1D_2 975_0 i.85 765.93C1% $3S5 1D AV 984.38 4.72 802.74C1%$3S5 7D_l 1537.5 ......Ci%$3S5 7D 2 1312.5 ......ci%$3S5 7'i_'=-AV 1425.0 ......C1%$3S5 28D_1 1481.25 ......C1%$3S5 28D_2 12i8.75 .............................

C1%$3S5 28D AV 1350.0 ......

256

m

m FRC - Fiexurat Test at I,7, and 28 days- Hgbrld Hlx

o_- 30/50 + 50/50 Hooked Steel Fibers

- /.,, V? = IX

. / %t,qI

_ bl/"',, '_,, - - -7 daus

.00 .10 20 .30 .40 .50 .60

DEFLECTION (in)

Fig. B.1 - Effect of Time on Load vs. Deflection Response, 30/50 + 50/50 Steel Fibers,(Vf=l%)

/o_F FRC - flexurat Test at L 7, and _8 days

/

!" Hybr'ld HIx

ooI- 30/50 �50/50Hooked Steer Fiber's!" ,''- VF = IX

_I-,"A_

...'% .... "'.°.......%

,oo .o3 ,os .o9 ._e ._5STRAIM CAPACITY (an/In)

Fig. B.2 - Effect of Time on Load vs. Strain Capacity Response, 30/50 + 50/50 SteelFibers, (Vf=l%)

257

dI

FRC - Ftexur,atTest ot 1,7, and 28 daysHybr,_dHix30/50 Hooked Steel + I/2'

Potypr,opytene Fibers

_0. _ VF = 1'?.

u_ ...............I day

- - - 7 dags

_ _ 28 daysr6

o_

.00 .10 .PO .30 .40 .50 .60

DEFLECTION (an)

Fig. B.3. Effect of Time on Load vs. Deflection Response, 30150 Steel +1/2" Polypropylene Fibers, (V£=1%)

dm

o,;- FRC - Ftexurat Test at 7 and P8 days- Ht,jbr'ld Mix

o6- 30/50 Hooked Steel �I/2'

- Potypr'opt,jtene FIber,sr_-. VF = 17.

-

__-i

V

u_-

. - - - - 7 days

<£ ,=. _1 __

-'J r6-_I

II

I

7 ---: ..........I

_" I I I I I I I i 1 ,.00 .03 .06 .09 32 .15

STRAIH CAPACITY (an/an)

Fig. B.4 - Effect of Time on Load vs. Strain Capacity Response, 30/50 Steel +1/2" Polypropylene Fibers, (Vf=1%)

258

o

o_- FRC - Ftexurot Test at I,7, and 28 days

_ Hybrld Hlx

0_- 30/50 Hooked Steer + I/2'

- Polypropytene Fibers

_0 r_- VF = 2X

v_ 'SF_.._ ...............1 dau

_[-/,;'_,_.,-- - --7 daus

ai

.00 .10 .20 .30 .40 .50 .60

DEFLECTInH (in)

Fig. B.5 - Effect of Time on Load vs. Deflection Response,30/50 Steel +1/2" PolypropyleneFibers, (V£=2%)

o_- FRC - Ftexurat Test at I,7, and 28 days

- H_Jbrld HIx I

a:i- 30/50 Hooked Steer + 1/2' I

- Potypropytene Fibers I

v,- I_.._ ...............1_,o,, I

,-, -',_._ - - - 7 days I_: L --28 days

I I I I I i i.00 .03 .06 .09 A2 .15

STRAIM CAPACITY (in/in)

Fig. B.6 - Effect of Time on Load vs. Strain Capacity Response, 30/50 Steel +1/2" Polypropylene Fibers, (Vf=2%)

259

FRC - Ftexurat Tes_ cL_ L 7. and e8 dayse,,,e

Latex Mix

50/50 _ooked S_eeL Fibers

VF = I_

Lf) _lCL r_ ...............! dayy , - - - 7 day

_ ', 28 day.-" "'... •

"". •

[] _r :

: ""'.....

...... ..................: "... ..(_J : "..

.00 .10 .20 .30 ,40 .50 .60

DEFLECTIDM (in)

Fig. B.7 - Effect of Time on Load vs. Deflection Response, 50/50 Steel Fibers,(Vf=l%)

,,...4

FRC - Ftexurat Test al: 1, 7, and ;)8 daysLa'l:ex Hix

o_ 50/50 Hooked Steer Fibers

a_ V£ = 1_.

C]. r_ ""................ 1 dQ_jy

v _ -,,, - - -7 d"_J"- _ ;)8 datj (Shear Failure)

[d . ......

°..... 'b_

I I I I I I.00 .03 .06 .09 .IP ,15

STRAIH CAPACITY (in/in)

Fig. B.8 - Effect of Time on Load vs. Strain Capacity Response, 50/50 Steel Fibers,(Vf=l%)

260

o_

: ___C___I:x-°__'"°___°°"_""°_- 1/2" PotypropyLene Fibers- V# = 17.

uS_- - - -7 day

.00 .10 .20 .30 .40 .50 .60

DEFLECTIOH (in)

Fig. B.9 - Effect of Time on Load vs. Deflection Response, Latex,1/2" Polypropylene Fibers, (Vf=] %)

c5i

o_- FRC - Flexurat Test st 1, 7, and P8 d_ys- Latex Hix

oo- 1/2' Poiypropyiene Fibers- V,F = 17.

-

__-................ I d_y

.... 7 dayI

I_ _ 28 d_y

r7

d_ir-°°_

ai

. - -?--"---..'..--'---.---.-..':=r.::__ °......

i I i I I I ....i ...........I........-7-"----,00 .03 .06 .09 .1P .15


Fig. B.10 - Effect of Time on Load vs. Strain Capacity Response, Latex,1/2" Polypropylene Fibers, (Vf=1%)

261

°

/'_ FRC - I:'|exurot Tes'l; a't I, P, end :_8 doqsIt

/\ sit,co ru.e MixO_ /\ 50/50 Hooked Steel F'd0ers

* t . . / VF : IL_i "I ., t

:/ ..............I doy

.+ :: ':_\ .__de do,y

_: ,: . •....r: • "'-

e+ -'L...........+d

I t | I I I I I I I I.00 .10 .20 .30 .40 .50 .60

DEFLECTION (in)Fig. B.11 - Effect of Time on Load vs. Deflection Response, Silica Fume,

50/50 Steel Fibers, (Vf=l%)c_

_"/__, FRC - FLexuraL Test at I,7, and 28 days

SILICa Fume Mix

50/50 Hooked Steel Fibers

-'" VF = I?.r,,[

I day%%%%I...-.

j o • * °.. • .euoeoeemmHse

,_j_ _,.o ... -_............ _',,", - - - 7 day

,_ _... __ 2ed_A ..... ;:.- .,:..,<E _ ...,,,.r,_ ,_.,.°

-

I I I I I I I I.00 .03 .06 .09 .1;) .15


Fig. B.I2 - Effect of Time on Load vs. Strain Capacity Response, Silica Fume,50/50 Steel Fibers, (Vf=l%)

262

B

oq- FRC - Ftexurat Test at L 7, and 28 days- SltlcaFume Hlx

od- 1/2' Potgpropytene Fibers

rC i V_=l%

v ................ I dag

.... 7 dag

_:- _ P8 day

r_;#[ l'<k i""__ J J l J l l l.00 .10 .20 .30 ,40 .50 .60

DEFLECTION (in)Fig.B.13 - Effectof Time on Load vs.DeflectionResponse,SilicaFume,

1/2" Polypropylene Fibers, (Vf=1%)

oq 7, Qnd 28 days

_- SILica Fume HIx _

o_ I/2'Potypropglene Fibers

r_ VF= IY.

...............1 day

_- - - -7 dQy

-J _

.00 .03 .06 .09 .IP .15

STRAIN CAPACITY (in/in)

Fig. B.14 - Effect of Time on Load vs. Strain Capacity Response, Silica Fume,1/2" Polypropylene Fibers, (Vf=1%)

263

/

o_F FRC - Ftexurat Test a'l: 1. 7. and 88 daysh Silica Fur,re Mix

aJ [- 30/50 + 50/50 Hooked S't:eel, FibersI- vf = t_:

r<l-

_--_v_ "__'",, ................1 day

U'J[-[.."'".._',, - - - 7 datJ

(_ .... .".:.v......;* • .. .....

I I I I I.00 .10 .20 .30 .40 .50 .60

DEFLECTIDM (in;,

Fig. B.lS - Effect of Time on Load vs. Deflection Response, Silica Fume,30/50 + 50/50 Steel Fibers, (Vf=l%)

d

"Lm

oq- FRC - Flexurat Tes_ at 1, 7, and 28 dagsSltlca Fune HIx

o_ 30/50 + 50/50 Hooked S_eet Fibers

. VF = IZ

_c3.,_ ,,,. ...............z dayv"Y , ...... _._", - - - 7 day

""'........... " , _ P8 day:.-" "°'_'"...o..o.. _

,q_ _: '... -,[_ _ '""°'°"-.%° _

...1 e.i

ai ! _.m

_ -

I I I I I I I I I.00 ,03 ,06 .09 .1P .15

STRAIN CAPACITY (In/In)

Fig. B.16 - Effect of Time on Load vs. Strain Capacity Response, Silica Fume,30/50 + 50/50 Steel Fibers, (Vf=l%)

264

°O

FRC - Ftexurot Test at 1 dogConporotlve Evo[uatlon

06 1/2' Potgpropgtene FibersV¢ = I%

L_

_Y Hol.dslzeJ4' x 4' x 16"%=S

u_ -- Con'trot

...............PtalnFRC,_ _ - - - SI|Ico FuMe[] = Latex

.,,.

,,

"'.....

"'."... ,.

.00 .10 .20 .30 .40 .50 .60

DEFLECTIDH (in)Fig. B.17 - Effect of Additive on Load vs. Deflection Response, 1 Day,

1/2" Polypropylene Fibers, (Wf:l%).

FRC - Ftexurot Test ot 28 dogs

Comporol;IveEvotuo1:mon

o_ I/2' Potgpropgtene FibersV? = I%

v___ Motd slze,4" x 4' x 16'-- ControI...............PtalnFRC

_ - - - SlIlCoFume

I_1 : Latexr_

oJ

..4

I 1 i I I I I.00 .10 20 .30 .40 .50 .60

I)EFLECTIFIH (in)Fig. B.18 - Effect of Additive on Load vs. Strain Capacity Response, 1 Day,

1/2" Polypropylene Fibers, (Vf=l%)

265

C_

I

o_- Hybrid FRC - Fiexural Test at 1 dog- Comparative Evatu(xtlon- 30/'50 + 50/50 Hooked Steel Fibers

- V? = 1Z_-_ I_ -L_ --

._0-_i -I Hold size, 4' x 4" x 16'

" • . Control

l-I"_', ...............Plo,_F_C

o ri _..".. . Latex_! c6 ....%,

I I I I I I I I I I I

.00 .I0 .ao .30 .40 ,50 .co

DEFLECTIDH (in)Fig. B.19 - Effect of Additive on Load vs. Deflection Response, 1 Day,

30/50 + 50/50 Steel Fibers, (Vf=l%)°

o_ Hybrid FRC - FlexuraL Test _t P8 daysComparative Evatuatlc, n

o_ 30/50 + 50/50 Hooked Steel Fibers

VF = IZ

t ",

: t ",EL_ : ,__ , :- Hold size, 4" x 4' x 16'

' _ Con_r'oI[_ | -I

' "................ Plain FRC

<:_ _: , ... - - - Sltlco, Fume[] "" "".. ,_. L_'t.e,K_1 oi -.. "'.

°v-4

I I I I I I I I I,00 .10 .eO .30 .40 .50 .60

]3EFLECTIFIH (in)Fig. B.20 - Effect of Additive on Load vs. Strain Capacity Response, l Day,

30/50 + S0/S0Steel Fibers, (Vf=l%)

266

2OOO

1800 _ "1600

1400

1200,m

o..1000

o-- c_ Jo',- 800 ..-K

----"--- Control400 o Vf=1%

200 -- Vf=2%

i I !

1 7 28

Time, days

Fig. B.21 - Modulus of Rupture fr vs. Time, 30/50 Steel Fibers

1000

800

600D..

400--'_-- Control

A Vf = 0.15%200 O Vf=1%

-- Vf=2%

I I I

1 7 28

Time, days

Fig. B.22 - Modulus of Rupture fr vs. Time, 1/2" Polypropylene Fibers

267

2000

lsoo1600

14oo•_ 1200

1000

800 .-x

600 _ "_---'_--- Control

400 -o Vf=1%-- Vf=2%200

0 I I I

1 7 28

Time, days

Fig. B.23 - Modulus of Rupture fr vs. Time, 30/50 + 50/50 Steel Fibers

1200

1000

.- 800 r_'___

600 .........."=.-

400 ----_--- Controlo Vf=1%; Vf=2%

200

I I I

1 7 28

Time, days

Fig. B.24 - Modulus of Rupture fr vs. Time, 30/50 Steel + 1/2" Polypropylene Fibers

268

2000 .... _--- Control18oo o 50/20

a Polypropylene fibers /_1600 -"- 30/50 + 50/50 _1400

•_ 1200

1000

_" 800 ..-K

600

400

2OO

I 1 I

1 7 28

Time, days

Fig. B.25 - Modulus of Rupture fr vs. Time, Latex, (Vf=1%)

2O00

1800

1600

1400

"_ 1200

1000i,,."

8006OO---"_--- Control

400 o 50/50

200 [] Polypropylene fibers-'- 30/50 + 50/50

I 1 I

1 7 28

Time, days

Fig. B.26 - Modulus of Rupture fr vs. Time, Silica Fume, (Vf=1%)

269

2oooi1800-

1600"

1400

'_ 1200D,,

1000

"- 800 .........=

600 m.................. -w........... -_--- Control

400 -----o Plain FRC

200 m'o Latex Modified FRC-_ Silica Fume Modified

I I !

1 7 28

Time, days

Fig. B.27 - Effect of Additive on the Modulus of Rupture fr vs.Time,50/50 Steel Fibers, (Vf=I%)

1000

800 _

•_ 600 _'"D,.

" 400

---"w--- Controlo---- Plain FRC

200 [] Latex Modified FRC

•_ Silica Fume Modified

1 I I

1 7 28

Time, days

Fig. B.28 - Effect of Additive on the Modulus of Rupture fr vs. Time,

Polypropylene, (Vf=1%)

270

1800

1600

1400

120OiE

_. 1000

800 K

600' H. .-w

' ---"_--- Control4O0 - , o Plain FRC

n Latex Modified FRC200

A Silica Fume Modified -

I I !

1 7 28

Time, days

Fig. B.29 - Effect of Additive on the Modulus of Rupture fr vs. Time,30/50 + 50/50 Steel Fibers, (Vf=1%)

271

20 Type of Fibers:1/2" Polypropylene

Vf = 2%

....... q -.--o-- 15-1stCR_ ----o 15-CO

"1oc _ .... 4-- IIO-lstCR-- _' _" = I10-C0t_ 10t/J O- ... _

C b " -. O, ,_

oI-

0 i ! i

1 7 28

Time, days

Fig. B.30 - Toughness Index Is and I1ovs. Time, 1/2" Polypropylene Fibers, (Vf=2%)

30 "_ Type of Fibers:30/50 Hooked Steel +50/50 Hooked Steel

---o-- Vf = 1%

= 15-CO _--x"¢_ 20 --4-- IlO-lstCR ---"""""_'10_- : 110-CO

m

o" 10

O ..... O- O

1 i i

1 7 28

Time, days

Fig. B.31 - Toughness Index Is and I1ovs. Time, 30/50 + 50/50 Steel Fibers, (Vf=1%)

272

70 Type of Fibers:30/50 Hooked Steel +

60 _ 50150 Hooked SteelVf = 2%

. 50' _ --.o-- 15-1stCR

x _ o_ 15-CO

•o _ --4-- I10-1stCRc: 40 ---t--- I10-CO

= \

= 2OO

10 ........

0 ___1 7 28

Time, days

Fig. B.32 - Toughness Index Is and Ilo vs. Time, 30/50 + 50/50 Steel Fibers, (Vf=2%)

30- Type of Fibers:112" Polypropylene +

30/50 Hooked Steel

25 Vf = 1%

,. -- ,o-- 15-1stCRi&

20 .% - _- 15-CO%

.% --,,,-- I10-1stCR"o \

.%

_= .---.---i10-co15 .% _ ..."

l- 10 o. x

_- 5'

0 281 7

Time, days

Fig. B.33 - Toughness Index Isand Ilo vs. Time, 30/50 Steel + 1/2" PolypropyleneFiber, (Vf=1%)

273

10

--w_" Type of Fibers:--... 1/2" Polypropylene

"-.. Vf = 1%8 _ " ",t Chemical Additive:

"x _ _\ Silica Fume

C \

t-

---o-- 15-1stCR0

o 15-C0 ,, _4-- IlO-lstCR "_o-- I10-C0

I I I

1 7 28

Time, days

Fig. B.34. Toughness Index Is and I10 vs. Time, 1/2" Polypropylene Fibers,

Silica Fume, (Vf=l%)

40Type of Fibers:

30150 Hooked Steel +50150 Hooked Steel

Vf = 1%30' _ Chemical Additive:I,,,,,,,I

Silica Fumex"oJ "_. - - ,o -- - 15-1stCR

_= °- is-co--t--- IlO-lstCR2O

"%.

m - _=..-= _- -- I10-C0

_ r ''_

OI-- o- ...............

0 | i i

1 7 28

Time, days

Fig. B.35 - Toughness Index Is and Ilo vs. Time, 30/50 + 50/50 Steel Fibers,

Silica Fume, (Vf=1%)

274

120

o 30/50

1O0 % a Polypropylene Fibers

o 80 _ :- 30/50 + 50/50O

c_ 6O

Ill

4O-II

2O[1,,

I ! I

1 7 28

Time, days

Fig. B.36 - Toughness Index 12o -co vs. Time for Different Mixes, (Vf=2%)

60

50

.. 40o

"" 30

20

o

,o • _o,so+so,so \: Polypropylene +30150 __

I I I

1 7 28

Time, clays

Fig. B.37 - Toughness Index Izo-lst-CRvs. Time for Different Mixes, (Vf=2%)

275

5O

40

o3O

0

o•.o Polypropylene Fibers

., 20 -- 30/50 + 50/50

10 c_"'U

I I 1

1 7 28

Time, daysFig. B.38 - Toughness Index I2o-co vs. Time for Different Mixes, Latex, (Vf=1%)

IO0

" 50/50" Polypropylene Fibers

80 _-- 30/50 + 50/500o 6O

O4

,-- 40

20

0 , ! !

1 7 28

Time, days

Fig. B.39- ToughnessIndex I20 -co vs. Timefor DifferentMixes,SilicaFume, (Vf=l%)

276

Appendix C

Fatigue Tests

Fig. C.1 - C.7 : Load versus Deflection Hysteretic Response under

Fatigue Loading

Fig. C.8 - C12 : Variation of Deflection versus Number of Cycles

Fig. C.13 : Load versus Deflection Response after Fatigue Loading

Fig. C.14 - C18: Variation of Strain versus Number of Cycles

Fig. C.19 - C20: Load versus Strain Response after Fatigue Loading

Fig. C.21 - C30: Load versus Strain Response under Static Loading

Fig. C.31 - C38: Load versus Strain Response under Static Loading

277

8.00 .... f .... ! .... ], ,- ......

....................._.. i S.p._c#47.oo . _......................_.................._-_=-_-.3...................................

: 3 Cycies 5 cy_cles -_.... ^o,_,,,,o/_6.00 :-......................-'.............._.'.T..T. ........R_-u=: ........,=..7=.-.=u.:/=_

ii!, i!iiiiiiiiiiiiiiiiiii:ii:iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiill4.00 .......

1.00

o.oo .... ;,,,, i .... J .... j , , , ,0.000 0.010 0.020 0.030 0.040 0.050

Deflection (in)

Fig. C.1 - Load versus Deflection Hysteretic Response of Specimen #4 underFatigue Loading

12.00 ........... ! .... I ....spec#121

10.00 .......................-........................_.................A2%S3 .............i........................i.. , ! Range: 10_/o-90%_i_ycle ! i . i

8.oor-....................i:7"t:5!cycles........i----23cyo,es...................

................, .........i......................i.........................i......................i0 4.00 ........................ _..................;.........................;.......................

2.00

0.000.000 0.010 0.020 0.030 0.040 0.050

Deflection (in)


278

12.00 Spec #1_ iL_ .................;10.00

_, iiiiiiii_i!,_, 8.00 ...............................................................=o= s.oo i l...,I 4.00 F / I N, : 2[i. • i "

2.000.000.000 0.020 0.040 0.060 0.080

Deflection (in)

Fig. C.3 - Load versus Deflection Hysteretic Response of Specimen#1S underFatigue Loading

8,0 ......... , ......... i .........Specimen #.5

7,0 ---_-2%-s_..........t..................... t.................................Range: 10%-80% i

6.0 ......................................i......................T_O-_yc]__...............

E 5.0 ...............i_ .........................

4.0 ........::::........ii!!!::::::::::::::::::::::::::::::::::::_,o_.o ............:T2.0__ ................h_;:_l ....1.0 ,,,__ ...... _ T ,....

0.0 '''' ..... i ......... I .........0.000 0.005 0.010 0.015

Deflection (in)


279

14.00 ' ' ' #1"2" ' ' ' .........Spec . i2.oo _A_:_s_:s5............_........................................................................

Range:j 10%-80%10. 00 "_"_;_i_'"'3"OO0'-c_6000-_C, yC1m_........_......................-v j y : : i "

8.00 ........................... i ..................' ..................i......................"o 500 c cles010 6.00.J

..oo ................,.oo0.000.000 0.010 0.020 0.030 0.040 0.050

Deflection (in)


10.00 ......... I ......... I ........

Spec #10 j !A2%S38.0 0 -Range ._.....t-0%--70%.........................."........................................

[Pre-cracking_: IJ- cycle J-i 1000 cyc es 75000 cycles6.00 ....................................i............................._....................................

°' 4'002.00j-11: __-'-...... i_ _ i.!N+_.iiiii:i:iiiiiiiiii:!0 cycles -

o.oo _- l:0.000 0.010 0.020 0.030

Deflection (in)


280

12.00 I-1"Spec..................._24 iLA2%S3S5 ! i

1o.oo ,.g;;;;_iT;i6g:_ii_..................T.........................i.......................- i le I 0_)0 cyclesi 11950001 cycles" 3 cy.c s : _..................................... '_; ................... : ................. t ......................

=__,.oo i i i......................_. _ _.............. • ..............;.......................

,.o..iom6.00 i ]4.00 "" "-_/_1"__""

,oo ..................... "I , , , , "r .... I , , , , I ....0.00

0.000 0.005 0.010 0.015 0.020 0.025

Deflection (in)


281

0.050 ' ' ' i ............Spec #4Mix A.2%S3

,... 0.040 'Fatlggi"l:oudlrfg ......................................................................= Range:i 10% to J90%

0,030 ................................................'.....................................................................c:o

im

u 0,020 ....................-.........P.rna ...........---.......................................

0,010 ............................................................

0.000 .... ; ' ' '0 2 4 6 8 10

Number of Cycles

Fig. C.8 - Variation of Deflection versus Number of Cycles for Specimen #4

0.070 ......... i ..................

Spec #20 i0.060 ""A'2"%S'2S3"......i................................................................................

,-.. Fatigue Loading._c 0.050 -'RangeT"l-0%"i-to--80% ..................T........................................

¢ 0,040 ........................................,...................._ma)_......+........................................

ou 0,030 ..................................4)

mqm

a) 0,020

D _80.010 ...................................................................................

Nf = 150000. 000 ...................... '''''

0 5000 10000 15000

Number of Cycles


282

0.050 ,,, ] ...............

Spec I #10A2%S3

0.0 40 -F_.__'_-L_'dr_ ....................................................................._c Range: 10% to 70%

0.030 .............................................................................................................

o Pmax,,i=,l

o 0 020

_- ! Pmin

0.010 _ :

Nf = 1081950.000

0 40000 80000 120000

Number of Cycles


0.050 ...........................Spec #24A2%S3S5

0.040 --Fattgue--EoadFng ............................................................¢ Range: 10% to 70%

°o.O_Oo......................................................................1N,=,,,oo_.lu 0 020 ..................................._o •"a) ... _.:._:. -e---'q_-_" j

0.010 _ ......i i

o. ooo ......... i ......... i .........o.o 1000000.0

Number of Cycles


283

0.050 .... ! .... i ................Speci #9 i

0.040 -..A2.PA,J_3..............i ..................................................................................-. FatigUe Loading

tm_ , .•- Rang_: 7.5.%-52.0%"" 0.030 ..........................................................................................................................

c Pmax.- 0.020 .................._..............................................................................._..................

= o.o,oC...............i....................[....................O. 000 _ ....... _...................._...........z_.._..................

.o.o_o _.... i .... j .... i ........ i ....0 2000000 4000000 6000000

Number of Cycles


12.00 .... I .... I .... I .... [ ....Static iTest Aftbr Fatig0e Loading

10. 0 0 _..5.2.Z.6.02.'8.........(_.y..(;.I._.ll...................................................................Spec #9 j,/"_ _

'o 6.00mo

_ 4.00

0.000.00 o.01 0.o2 o.o3 0.o4 o.o5

Deflection (in)

Fig. C.13 - Load Versus Deflection Response after Fatigue Loading forSpecimen #9

284

0.020 , , , i ............

Spec i#4Mix A_2%S3

o. o16 ....F_ii_ii_----L-_-aii;i-O.........................................................................c Rangei 10% tO 90%em

....'S_:_.o12 .......................i {

c 0 008 "i'_ P_ax................................................. -.....................i........................;.......................

............ .............0.000 ,,, i,,, J.,, i , , , , , ,

0 2 4 6 8 10

Number of Cycles

Fig. C.14 - Variation of Strain versus Number of Cycles for Specimen #4

0.020 .... ! ........................Spec: #5A2%!S3

o. o16 'FJ._eT.:_-em__...".................i.........Z'..."............_ ...............E Ran e: 10 to 0% _'

._= 0.012 ...............;..................;................._................;...............;............._.........................................................., ..............or)

o.oo, '2_......................................o.ooo __T,,,, ; .... i .... ; .... ; .... ; ....

0 1000 2000 3000

Number of Cycles


285

0.020 ......... i ..................

Spec #20 iA2%S2S3 i

A o.o16 .....¢;;ii_;_[6_;]]fi_........................................................................c Range: 10%1 to 80%in

" 0 012 ........................................;................................................................................

" 0 008 ......................................lm •mk,,

o.oo, ...............................................................ooiNf= 150i j0. 000 ....................... ''''

o 5000 10000 15000Number of Cycles


0.005 .... i ................Spec i#9A2%8_3

O. 004 ....Puttglz.D'-t;oa'dlng .....................................................................c Range_: 7.5%.52.0%

•m

c 0.003 ............................................................................................................................

e-"- 0.002 ...........................................................................................................................I,,,

(n

0.001 ............................................._._.................i....................._........................

-- i i i i0,000 .... ' .... I .... I .... ,,,,,

0 2000ooo 4ooooooNumber of Cycles


286

0.01 0 .... I ................Spec #17A2%S3S5

o. oo8 'Fi_T___X:_idr_i ..................................................................._ Range'_ 7.1%-57.0%

c 0.006 ............................................................................................................................palm

e-•"- 0.004 ...............................................-...........................................................................L_

0.002

0.0000 2000000 4000000

Number of Cycles


287

1 2.00 ......... I ..................Static Test After Fatigue Loading

10. 0 0 ..5..2..7....6...0...2..8............C..y._.!..e....s.........................................................................Spec #9 _ iAGO/.R

_ o.oo -----.-----::------- ................................"o 6.00¢g0

"_ 4.00

2,00

o.oo ..... !.... i ......... ; .........0.000 0.005 0.010 0.015

Slrain (in/in)

Fig. C.19 - Load Versus Strain Response after Fatigue Loading for Specimen #9

20.00 ' ' ' t ' ' ' _ ' ' ' t ' ' ' J ' ' 'Static Test Afte_r Fatiguis Loadin_g5000000 Cyclds

1 6.0 0 -Spec-..--#l--7................_...........................................................................A2%S3iS5

_,12.00 ...............................................................................................................

m

o.oo 12111111,.j •

4.0O

0.00''' _ ' ' _,,, ,,,, 1 , , ,0.00 0.02 0.04 0.06 0.08 0.10

Strain (in/in)

Fig. C.20. Load Versus Strain Response after Fatigue Loading for Specimen #17

288

8.007.00

600

_'_ 5 O0

"_m 400

o 300

200

IO0

0000.00 0.05 0.10 0.15 0.20 0.25

Deflection (in)

Fig. C.21 - Load versus Deflection Response under Static Loading forSpecimen #I

8.00., ........... ] ............ I .... i .... -

7.oo ..........................................................................................spo¢...._3.......

.................A2..s..........."Ooe=400 i-J 3 00 ............_............................_............................._...............*...............;.............

oo1 O0 ....

0 O0 .... i .... , .... i .... I .... i .... i .... i ....0.00 0.10 0.20 0.30 0.40

Deflection (in)

Fig. C.22. Load versus Deflection Response under Static Loading forSpecimen #3

289

8.00 ............ j .... J ....

7.oo -/_..........._........................._.........................i............sp._._s........

.-. 6.00 _i! i i A2%63

5.00

o4.00 ial0

,.I 3.00 ....................................................................................._.......................

1.00

0 00 .... J ,,,, _, ,,, _, ,, , i, , , ,e

0.00 0.10 0.20 0.30 0.40 0.50

Deflection (in)

Fig. C.23 - Load versusDeflection Responseunder Static Loading forSpecimen #6

8.00 .... I ............................" I 1

7.00 ................ _...............:...............:...............:.........S c.....#7...........• i i i i ! A2%S3i

6.00

_" 5.00

•0 4.00m

-I 3.00 ............:...............:............_-..............._..............._..............._..............._............

2.OO

I .00

0.000.00 0.10 0.20 0.30 0 40

Deflection (in)

Fig. C.24 - Load versus Deflection Response under Static Loading forSpecimen #7

290

10.00

8.00 .........._. 6 00

o, 400

200

0.000.00 0.10 0.20 0.30 0.40 0.50

Deflection (in)

Fig. C.25 - Load versus Deflection Response under Static Loading forSpecimen #II

8.00 .... .... i ........ I ....

-/_.............:.........................i.........................i........s,p.e.c...!..#.n...........

,.oo _!i. ! i A_%s_s_oo_" 5.00

3.00 ......................_............... .

OOoo iiiiiiiiiiiiiiiiiiiii!iiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiill0.000.00 0.10 0.20 0.30 0.40 o.so

Deflection (in)


291

10.00 ................ i ....

/'_ Sped #14

6.00 .............................................

"IDt_

oo0..I "

2.00 .........

0.00 ,,,, _ , , , I .... I .... i ....0.00 0.10 0.20 0.30 0.40 0.50

Deflection (in)


1500. ........ _ ............ I ....i

Spe¢i #19A2%I;3S5

i

,-.10.00.:¢

"at_

o i.J5.00 ...................................

0.00 ,,,, i, ....... i .... _ .... I ....0.00 0.05 0.10 0.15 0.20 0.25 0.30

Deflection (in)


292

20.00 ....

15.00

"0 10.00

0.-I

5.00

0.000.00 0.10 0.20 0.30 0.40 0.50

Deflection (in)


15.00 ................ ! ....

Spe F 023A2%S3S5

_.-,°.°°o.........i.........................i.........................i................................................m

0 i'iil .......i''''i......................0.00

0.00 0.10 0.20 0.30 0.40 0.50

Deflection (in)


293

8.00 ............ I ' ' '

_,%..................... spec .3.1............7. oo ............_2

oo_ 5.O0

•o 4.000

•.J 3.00

2111111111111111111111iliiiiiiiiiiiiiiiiiiiiii!iiiiiiiiiiiiiI . O0 ..........._.......................

, , , i , , , , , , , , , i , , ,0.00

0.00 0.04 0.08 0.12 0.16 0.20

Strain (in/in)

Fig. C.31 - Load versus Strain Response under Static Loading forSpecimen #1

8.00 ............ 1 ....i

7. oo _ .................................................................................._.,_e._....#...e......

_" 5.oo

•o 400_I0

•_ 3.00

,00 ii iiiiiiiiiiii1.00

0 00. .... I ........ , _ , ,0.00 0.05 0.10 0.15 0.20

Strain (in/in)

Fig. C.32- Load versus Strain Response under Static Loading forSpecimen #6

294

10.00 ........ I ............

Spec # 11

, A2%i3

-iiiiii....................... "° imo 4.00.,J

,,oo....................i.......................7i........................i.........................f.......................0.00 .... J , , , , J .... f .... _ , , , ,

0.00 0.01 0.02 0.03 0.04 0.05

Strain (in/in)


8.oo_ sp_c,13 i7. O0 ............................. :.........................................................................

6.00

_" s.oo

4.00

o 3.00

2.0 0 ...................._........................"_.......................i.......................;......................_"

1.000.000.00 0.02 0.04 0.06 0.08 0.10

Strain (in/in)


295

10 O0 ......... I ' ' '

/_ Spe¢ # 14

800 I ............_i ......................-....................A2-°_"S3S"5 ............

.J

20O

0 O0 J , , 1 , , , I , ,,0.00 0.04 0.08 0.12 0.16

Strain (in/in)


15.00 ............ I ' ' '_:.

Spec #19

_,10.00 _ A2%S3S5 !"o¢lo_1

5.00 -

0.000.00 0.02 0.04 0.06 0.08 0.10

Strain (in/in)


296

20.00

,__15.00 ............. i............

"010.000,,,J

5.00

0.000.00 0.04 0.08 0.12 0.16

Strain (in/in)


15.00 ......... I ' '

Spec #23A2%S3S5

,...,10.00

IDcaO..J

5.00 --

0.00 , , . I , , , I , , , [ , , ,0.00 0.04 0.00 0.12 0.16

Strain (in/in)


297

Concrete and Structures Advisory Committee

Chairman Liaisons

James J. MurphyNew York Department of Transportation (retired) Theodore R. Ferragut

Federal Highway Administration

Vice ChairmanHoward H. Newlon, Jr. Crawford F. JencksVirginia Transportation Research Council (retired) Transportation Research Board

Members Bryant MatherUSAE Waterways Experiment Station

Charles J. Arnold

Michigan Department of Transportation Thomas J. Pasko, Jr.Federal Highway Administration

Donald E. BeuedeinKoss Construction Co. John L. Rice

Federal Aviation Administration

Bernard C. Brown

Iowa Department of Transportation Suneei VanikarFederal Highway Administration

Richard D. GaynorNational Aggregates Association�National Ready Mixed Concrete 11/19/92Association

Expert Task GroupRobert J. Girard

Missouri Highway and Transportation Department Stephen ForsterFederal Highway Administration

David L. Gress

University of New Hampshire Amir Hanna

Gary Lee Hoffman Transportation Research Board

Pennsylvania Department of Transportation Richard H. Howe

Brian B. Hope Pennsylvania Department of Transportation (retired)

Queens University Susan Lane

Federal Highway AdministrationCarl E. Locke, Jr.

University of Kansas Rebecca S. McDaniel

Indiana Department of TransportationClellon L. Loveall

Tennessee Department of Transportation Howard H. Newlon, Jr.

David G. Manning Virginia Transportation Research Council (retired)

Ontario Ministry of Transportation Celik H. Ozyildirim

Robert G. Packard Virginia Transportation Research Council

Portland Cement Association Jan P. SkalnyW.IL Grace and Company (retired)

James E. Roberts

California Department of Transportation A. Haleem T_ir

American Association of State Highway and Transportation

John M. Scanlon, Jr. OfficialsW'_s Janney Elstner Associates

Lillian WakeleyCharles F. Scholer USAE Waterways Experiment StationPurdue University

7/22/93Lawrence L. Smith

Florida Department of Transportation

John R. Strada

Washington Department of Transportation (retired)

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