STRENGTH AND BEHAVIOUR OF SCC AND SFRSCC EXTERIOR … · Airo International Research Journal Volume...

Airo International Research Journal Volume VIII, December, 2016 Dissertation Publication ISSN: 2320-3714

1

DISSERTATION

STRENGTH AND BEHAVIOUR OF SCC AND SFRSCC

EXTERIOR BEAM-COLUMN JOINT UNDER CYCLIC LOADING

For The Degree of Master of Technology ( Civil Structural )

Submitted By: Mayank Kumar

Univ. Roll No.:- 16089446

Univ. Reg. No.:- B2EMT(CE)100045

Session: - 2014 - 2016


2

STRENGTH AND BEHAVIOUR OF SCC AND

SFRSCC EXTERIOR BEAM-COLUMN JOINT

UNDER CYCLIC LOADING

Dissertation Published

On

December, 2016


3

CERTIFICATE

I certify that the substance of this thesis has not already been submitted for any

degree and is not currently being submitted for any other degree or

qualification.

I also certify that, to the best of my knowledge, any help received in preparing

this thesis, and all sources used have been acknowledged in this thesis.


4

Dedicated To

My Parents , Family and to my Respected teachers and special

thanks to my father for all his support and to all my loved ones &

Friends.…………………………


5

ABSTRACT

The beam-column joint is one of the most critical sections in the design and

construction of the structure. In these areas, a high percentage of transverse hoops in the core

of the joint are needed in order to meet the requirement of strength, stiffness and ductility

factor under cyclic inelastic flexure loading. The beam column joint subjected to cyclic

loading require great care in detailing. Diagonal tension cracking is one of the main causes of

failure of joint. The satisfactory performance of a beam column joint depends strongly on the

lateral confinement of joint. The present study deals with the non-conventional reinforcement

detailing of the beam column joint that provides inclined bars on the two faces of the joint

core. The performance of beam column joint has been a research topic for many years. The

anchorage length requirements for beam and column bars, the provision of transverse

reinforcement, the design and detailing of the joint are the main issues. Several researches

have reported their test results using SFRC in framed beam column joints. All these tests

have shown the effectiveness of using steel fibers to increase the joint strength, ductility and

the energy absorption capacity. Provision of high percentage of hoops leads to congestion of

steel leading to construction difficulties. These difficulties can be removed by using self-

compacting concrete (SCC).


6

Multi-storey reinforced concrete structural frames are among the most congested

structural elements. Placing and consolidating concrete in such structural frames imposes

substantial technical challenges. This offers a unique area of application for self-

consolidating concrete because of its inherent ability to flow under its own weight and fill

congested sections, complicated formwork and hard to reach areas. However, research

is needed to demonstrate the ability of SCC structural frames to adequately resist vertical and

lateral loads. In the present study, full-scale 3-m high beam-column joints reinforced as per

the Canadian Standard CSA A23.3-94 [1] and ACI-352R-02 [2] were made with ordinary

concrete and self-consolidating concrete. They were tested under reversed cyclic loading

applied at the beam tip and at a constant axial load applied on the column. The beam-column

joint specimens were instrumented with linear variable displacement transducers and strain

gauges to determine load-displacement traces, cumulative dissipated energy and secant

stiffness. This paper compares the strength and behaviour of SCC and SFRSCC exterior

beam-column joint under cyclic loading and discusses the potential use of SCC in such

structural elements.


7

TABLE OF CONTENTS

CHAPTER 1: INTRODUCTION ................................................................................ 10

1.1 Research Background ......................................................................................... 12

1.2 Significance of the Study ................................................................................... 19

1.3 Objectives of the Study ...................................................................................... 19

CHAPTER 2: CONCEPT OF SCC ............................................................................. 20

2.1 Application Area ................................................................................................ 23

2.2 Requirements ...................................................................................................... 23

2.3 Properties ............................................................................................................ 24

2.4 Self-Compacting Concrete Uses ........................................................................ 24

2.5 Factors Affecting Self Compacting Concrete .................................................... 26

2.6 Self-Compacting Concrete Special Considerations ........................................... 26


8

CHAPTER 3: CONCEPT OF SFRSCC ...................................................................... 27

3.1 Effect of Fibers Utilized With Concrete ............................................................ 27

3.2 Applications ....................................................................................................... 28

3.3 Properties ............................................................................................................ 28

3.4 Limitations of Steel Fiber Reinforced Concrete ................................................ 29

CHAPTER 4: Literature Review ................................................................................. 30

4.1 Self-Compacting Concrete ................................................................................. 30

4.2 Steel Fiber Reinforced Self-Compacting Concrete ............................................ 34

4.3 The Particle-Matrix Model ................................................................................. 42

4.4 Bingham‟s Model ............................................................................................... 45

4.5 Compressible Packing Model............................................................................. 46

CHAPTER 5: MIX DESIGN OF SCC AND SFRSCC ............................................... 47

5.1 Materials Required For SCC and SFRSCC ....................................................... 47

5.2 Mix Proportion of SCC and SFRSCC ................................................................ 49

5.3 Testing of SCC and SFRSCC............................................................................. 50

CHAPTER 6: EXPERIMENTAL PROGRAMME AND TEST RESULTS .............. 52

6.1 Design of Beam-Column Joint ........................................................................... 56

6.2 Description of Beam-Column Joint Specimen ................................................... 57


9

6.3 Testing of Specimen ........................................................................................... 57

6.4 Experimental Set Up .......................................................................................... 58

6.5 Behaviour of Specimens..................................................................................... 58

6.6 Test Setup and Procedure under Reversed Cyclic Loading ............................... 61

CHAPTER 7: ANALYSIS OF TEST RESULTS AND DISCUSSION ..................... 65

7.1 Load - Displacement Envelope Relationship ..................................................... 71

7.2 Cumulative Dissipated Energy ........................................................................... 72

7.3 Secant Stiffness .................................................................................................. 73

CHAPTER 8: CONCLUSION .................................................................................... 76

BIBLIOGRAPHY ........................................................................................................ 78


10

CHAPTER 1: INTRODUCTION

The widespread employment of concrete in structures has been among us for

millenniums, probably, since the Egyptian civilization (Campbell and Folk 1991). However,

it was during the Roman Empire that the arisen of this material enabled a revolution on the

construction of structures, namely, on concrete vaulted structures. Consequently, back on

those days, this allowed and pushed to revolutionarily new designs both in terms of structural

complexity and dimension, e.g. Pantheon and Basilica of Maxentius (Lancaster 2005).

Concrete is presently no more a material comprising of cement, aggregate, water and

admixtures. It is in fact an engineered material with a few additional constituents. The

concrete today can deal with any particular necessities under the most critical conditions.

New age concrete needs to fulfill different execution criteria i.e., it ought to have high

fluidity, self-compatibility, high strength, high durability, better serviceability and long

service life. In order to satisfy these criteria self-compacting concrete (SCC) was developed.

SCC is a mix that can be compacted into every corner of formwork by means of its own

weight and without the need for either external or internal vibration for compaction, and also

without affecting its engineering properties. The use of such concrete saves time, labor and

energy. The requirement of SCC is not only the need of modern fast growing urban cities but


11

also special applications in special engineered structures like bridges and under water

construction where concrete without vibration is in demand.

Though concrete possess high compressive strength, stiffness, low thermal and

electrical conductivity, low combustibility and toxicity but two characteristics limited its use

are, it is brittle and weak in tension. However the developments of Fiber Reinforced

Composites (FRC) have provided a technical basis for improving these deficiencies. Fibers

are small pieces of reinforcing materials added to a concrete mix which normally contains

cement, water, fine and course aggregate. Among the most common fibers used is steel,

glass, asbestos, polypropylene etc. When the loads imposed on the concrete approach that for

failure, crack will propagate, sometimes rapidly, fibers in concrete provides a means of

arresting the crack growth. If the modulus of elasticity of fiber is high with respect to the

modulus of elasticity of concrete or mortar binder the fiber helps to carry the load, thereby

increasing the tensile strength of the material. Fibers increase the toughness, the flexural

strength, and reduce the creep strain and shrinkage of concrete. [2] Several European

countries recognized the significance and potentials of SCC developed in Japan. During

1989, they founded European federation of natural trade associations representing producers

and applicators of specialist building products (EFNARC). The utilization of SCC started

growing rapidly.

Self-compacting concrete (SCC) offers several economic and technical benefits; the

use of steel fibers extends its possibilities. Steel fibers acts as a bridge to retard their cracks

propagation, and improve several characteristics and properties of the concrete. Fibers are

known to significantly affect the workability of concrete. Therefore, an investigation was

performed to study the properties as well as Strength and behaviour of self-compacting

concrete (SCC) and steel fiber reinforced Self-compacting concrete (SFRSCC).


12

1.1 Research Background

For the past two millenniums, the concrete technology has faced endless

developments, particularly, from mid of the eighteenth century. Since it is out of the scope of

this work and would be quite fastidious to enumerate them, a description of some of these

advances can be found elsewhere (e.g. Mindess et al. 2003). Even though the endless

breakthroughs, there are still some problems related to the utilisation of this material. More

precisely, these “problems” can be regarded rather as disadvantages from

cementiciousmaterials, in comparison to other materials commonly used nowadays, e.g. steel.

Concrete being a “quasi-fragile” material has almost no ductility, additionally, has a very low

tensile strength. Therefore, the utilisation of rebars is mandatory, in order to bridge the cracks

and to face up with the tensile forces which are often larger than the concrete‟s tensile

strength. Moreover, the concrete structures‟ self-weight is quite considerable, if comparing

with steel structures with the same bearing capacity, thus a great deal of concrete‟s material is

just for supporting the dead-loads. This larger amount of material, and “redundant” for the

final structural purpose of sustaining something, and not itself, besides the setbacks from a

sustainability point of view, will enhance the man-labour time used for mounting both the

rebars and the heavier choring systems. Finally, concrete is not a maintenance-free material.

During, the service life of concrete structures, they will be subjected to distinct grades of

loading, which may produce distinct grades of structural damage, i.e. cracks, hence

subsequently harmful substances can penetrate through cracks and cause the corrosion of

reinforcement. This is also influenced by the porous nature of concrete.

With regard to copping with the abovementioned disadvantages, in the past recent

years, have arisen several new cement based materials, such as: slurry infiltrated fibre

concrete (Hackman et al. 1992, Naaman 1992, Hauser and Worner 1999), SIFCON, steel

fibre reinforced self compacting concrete (Groth 2000, Gr¨unewald 2004, Schumacher 2006),


13

SFRSCC, engineered cement composites (Li and Leung 1992, Li and Wu 1992, Leung 1996),

ECC, high performance fibre reinforced concrete (Markovic 2006, Lappa 2007), HPFRC,

between other materials and designations. From these enumerated alternatives, the utilization

of SFRSCC poses a very feasible and rational solution to some problems of conventional

concrete. This material does not intend to solve all the referred disadvantages of conventional

concrete, but to greatly mitigate them. Recently, other materials as ECC and HPFRC

exhibiting multiple cracking, have shown astonishing mechanical performances, however

these have yet some drawbacks. In spite of their outstanding properties, until the present time,

structural realizations in ECC and HPFRC are yet scarce, mainly, due to (Kabele 2000):

Limited experience with ECCs‟ structural behaviour

Non-existence of design codes that would permit to take advantage from the

material‟s pseudo strain-hardening behaviour

High fibre cost, which makes the composite several times more expensive than

ordinary concrete

To deal with the first itemized reason, several experimental works have been

conducted in the past decade (e.g. Naaman 2003, Kanda and Li 2006, Markovic 2006, Lappa

2007). On the other hand, this material is quite onerous, mainly, due to the high fibre cost

which arises from the fact that, these advanced materials have been initially designed/tailored

with hitech industrial fibres, created originally for low-volume applications in aerospace and

military industry (Kabele 2000). As the material technology evolutes, this issue can be settled

down with the appearance and utilization of new low-cost fibres.

In what concerns the use of SFRSCC, this material introduces several advantages on

the concrete technology. In fact, the partial or total replacement of conventional bar

reinforcement by discrete fibres in certain concrete structures contribute to decrease their


14

construction time and costs, and collaborates for the enhancement of their durability. The

assembly of the reinforcement bars in the construction of concrete structures has a significant

economical impact on the final cost of this type of constructions, due to the man-labour time

consuming that it requires. Nowadays, the cost of the man-labour is significant; hence

diminishing the man labour will decrease the overall construction‟s cost. In the fresh state,

SFRSCC homogeneously spreads due to its own weight, without any additional compaction

energy. To homogeneously fill a mould, SFRSCC has to fulfil high demands with regard to

filling and passing ability, as well as segregation resistance. Driven by its own weight, the

concrete has to fill a mould completely without leaving entrapped air. For these reasons,

SFRSCC is a very promising construction material with high potential of application, mainly

in the cases where fibres can totally replace the conventional reinforcement. At the present

time, however, the SFRSCC technology is not yet fully developed and controlled, and, much

less, the mechanical behaviour of the SFRSCC material. This material, as briefly enlightened

in the previous paragraph, has its origins and congregates the benefits from two independent

types of concretes: self-compacting concrete, SCC, and conventional fibre reinforced

concrete CFRC.

Self-compacting concrete was first developed in Japan, in 1988, aiming to improve

the durability of concrete structures. The durability of concrete is intimately related to the

level of compaction achieved while casting. Therefore, the development of a self-compacting

concrete capable of being compacted purely by its own weight, i.e. without the need of any

external vibration system, and into some extent independent from the man-labour‟s quality,

started to seem a feasible alternative to be developed (Okamura and Ozawa 1996). The

employment of self-compacting technology renders great benefits, mainly, when used to

improve construction systems previously based on conventional concrete, which require

compaction operations. Moreover, the vibration systems commonly used in compaction can


15

easily cause segregation of concrete, thus jeopardizing its quality. The durability and

reliability of a concrete structure is dependent on the compaction made by skilled workers,

and if the aim is to achieve durable concrete structures independently from the man-labour‟s

quality, vibration compaction systems should be discarded.

On the other hand, short and randomly distributed fibres are often used to reinforce

cementitious materials, since they offer resistance to crack initiation and, mainly, to crack

propagation. In CFRC materials of low fibre volume fraction the principal benefits of the

fibres are effective after matrix cracking has occurred, since fibres crossing the crack

guarantee a certain level of stress transfer between both faces of the crack, providing to the

composite a residual strength, which magnitude depends on the fibre, matrix and fibre/matrix

properties. The most benefited properties by the fibre addition to the concrete, in the concrete

hardened state, are the impact strength, the toughness and the energy absorption capacity. A

detailed description of the bene-fits provided by the fibre addition to concrete can be found

elsewhere, (Balaguru and Shah 1992, Casanova 1996, ACI 544.1R-96 1996). The fibre

addition might also improve the fire resistance of cement-based materials (Kodur and Bisby

2005), as well as the shear resistance (Rosenbusch and Teutsch 2003).

Nevertheless the widespread use of SFRC on full load bearing structural applications

is yet to some extent limited, if having in mind that the appearance of this material dates back

to the early sixties. The high scatter of the SFRC material behaviour, in part due to non-

uniform fibre dispersion, conduces to the mistrust in this material. In order to overcome these

doubts it is of vital importance reducing the material behaviour scatter and, consequently,

enabling the adoption of lower material safety factors (Shah and Ferrara 2008). Thus, it is

necessary to effectively control the fibres dispersion within a structural element along its

manufacturing and casting process. An improper casting of a structural element will lead to a

higher non-uniformity in the fibres dispersion, which could result in reduced or even nil


16

amounts of fibres on certain spots of the structural element. These locations may jeopardize

the structural performance either in terms of failure mechanisms and ultimate loads (Ferrara

and Meda 2006, Shah and Ferrara 2008).

The use of self-compacting matrices takes advantage of the elimination of any kind of

external vibration and rheological stability in the fresh state, which assures a more uniform

distribution of fibres within the structural elements (Shah and Ferrara 2008). Self-compacting

concrete is effective in guaranteeing a more uniform dispersion of fibres within the specimen,

as well in effectively orienting them along the casting direction. When comparing the fibre

distribution in plates of self-compacting concrete and conventional vibrated ones, the fibre

dispersion is almost twice as much scattered in the vibrated ones (Shah and Ferrara 2008).

Throughout a suitable balance of the fresh state concrete properties, mainly the fluid

viscosity, fibres can be effectively oriented along the direction of the flow (Ferrara et al.

2007, Stahli et al. 2008). Therefore, it is desirable to design, together with the mix

composition, also the casting procedure, so that the concrete flow direction along which

fibres may be aligned, coincide with the direction of the principal tensile stresses within the

structural element when in service, and consequently enhance the structural performance

(Ferrara et al. 2008).

In the beginning of this thesis you will find a brief description of the basic theory for

proportioning of concrete. This includes the theoretical models for analysis used in this thesis

followed by the basics of the materials used in concrete. Further on is the basis for the

experiments, description of the experiments that are carried out and explanation of the

compressible packing model which forms the basis for the calculations. Last the results from

the experiments and the calculations are assembled and put up against each other and

discussed. A brief conclusion summarizes the results that are found in this thesis.


17

Damages in reinforced concrete structures are mainly caused to shear force due to the

inadequate detailing of reinforcement, the lack of the transverse steel and confinement of

concrete in structural elements. Typically failures are brittle in nature, demonstrating

inadequate capacity to dissipate and absorbs inelastic energy. The beam-column joints that

are subjected to reverse cyclic loading which require great care in detailing. Diagonal tension

cracking is one of the main causes of failure of joint. The satisfactory performance of a beam

column joints depends strongly on the lateral confinement of joint. The present study deals

with the non-conventional reinforcement detailing in the beam-column joint by providing

inclined bars on the 2 faces of the joint core, which leads to reduction in compaction and

construction difficulties due to congestion of reinforcement in the joint region. The

performance of beam column joint seismic conditions has been a research topic for many

years. The anchorage length requirements for beam and column bars, the provision of

transverse reinforcement, the design and detailing of the beams are the main issues

Normal Conventional concrete has been widely used as a construction material

throughout the world because of the advantages of mould ability, durability, resistance to fire

and energy efficiency. However the major deficiencies in conventional concrete are its poor

tensile strength, low ductility, dimensional stability etc. Hence in order to improve the tensile

properties, several new material have been developed in the recent past such as high

performance concrete, high performance fiber reinforcement concrete, polymer modified

concrete etc. Recently, Self compaction of fresh concrete has been recognized as a means to

improve the quality and constructability of concrete infrastructure. The self-compacting

properties are generally achieved by high deformability of fresh concrete mix, good

resistance against segregation and the low slump loss. The Steel fiber reinforcement is used

to increase the tensile properties in Self compacting concrete.


18

Self-compacting concrete is a mixture, which is suitable for placing in difficult

condition and in structures with congested reinforcement without vibration. It is characterized

by high powder content. The resulting concrete has an excellent surface finish. When large

quantity of heavy reinforcement is to be placed in a reinforced concrete member, it is difficult

to insure that formwork gets completely filled with concrete, which is fully compacted

without voids and honeycombs.

The definition of self-compacting concrete as described by the European Concrete

Platform is expressed as follows: “Self-compacting concrete (SCC) is an innovative concrete

that does not require vibration for placing and compaction. It is able to flow under its own

weight, completely filling formwork and achieving full compaction, even in the presence of

congested reinforcement” (European Concrete Platform, 2012) Knowing this, it is implied

that the industry can save many working hours by reducing the need for people vibrating the

fresh concrete to compact it. When there is no need for compacting, the quality assurance of

the vibrating as an uncertain factor, regarding the final result of the concrete, is ruled out. The

most used argument for not using SCC is that it is more expensive than regular vibrated

concrete. Despite the high expenses of SCC compared to regular concrete, it is probably more

profitable in use by reducing the expenses of vibrating, and by quicker casting. In addition

there are several other benefits with using SCC; With no need for vibrating, the working

environment is better, the surfaces are improved, there is less need for rework, the execution

is more rational, and we get more homogeneous concrete which gives better durability. The

downside with SCC is that because of the rheology, the formwork needs to be tighter for the

concrete not to flow out (Kvisvik, 2007).

Another way to save working hours is by adding fibres as a substitute to rebar. By

mixing fibres in the fresh concrete increased tensile strength in the hardened concrete can be

achieved without need for iron fixers prior to casting. Fibres in regular vibrated concrete is


19

more uncertain, due to that when vibrating, the fibres will form a cylinder around the vibrator

and may not be dispersed as required. A disadvantage by use of fibres is that the amount that

can be used is very limited. The reason is that when using a large amount of fibres the flow

properties of the concrete are reduced and in the worst case, fibre balling occurs, thus the

fibres are not properly dispersed, resulting in irregular and unreliable concrete. Different

manufacturers recommend different amounts of fibre. The recommended maximum amount

varies from 1.3 vol-% to 3 vol-% of concrete (Ochi, Okubo and Fukui, 2007).

1.2 Significance of the Study

In the design and construction of structures, one of the areas is the beam column joint.

In these areas, a high percentage of transverse hoops in the core of the joint are needed in

order to meet the requirements of strength, stiffness and ductility factor under cyclic inelastic

flexure loading. Typical failures are brittle in nature, demonstrating inadequate capacity to

dissipate and absorbs inelastic energy. The beam-column joint subjected to cyclic loading

require great care in detailing. Diagonal tension cracking is one of the main causes of failure

of joint. The satisfactory beamcolumn joint depends strongly on the lateral confinement of

joint. Several researches have reported their test results using SFRC in framed beam-column

joint. All these tests have shown the effectiveness of using steel fiber to increase the joint

strength, ductility and energy absorption capacity. Provision of high percentage of hoops

leads to congestion of steel leading to construction difficulties. These difficulties can be

removed by using Self Compacting Concrete (SCC)

1.3 Objectives of the Study

To develop Self compacting concrete satisfying the requirements of the fresh and

hardened state

To obtain a mix design for steel fiber reinforced self compacting concrete


20

To study the behaviour of structural elements such as beam-column joints made of

SFRSCC

To find the new way for the confinement of joint core by providing cross inclined

bars

To develop Steel Fiber reinforcement SCC and compare the same with plain SCC

To evaluate the behaviour of beam column joint made up of SCC and SFRSCC under

cyclic loading

CHAPTER 2: CONCEPT OF SCC

Self-compacting concrete (SCC) has been described as "the most revolutionary

development in concrete construction for several decades". Originally developed to offset a

growing shortage of skilled labour, it has proved beneficial economically because of a

number of factors, including:

Better surface finishes

Easier placing

Faster construction

Greater freedom in design

Improved durability

Reduced noise levels, absence of vibration

Reduction in site manpower

safer working environment

Thinner concrete sections

Originally developed in Japan, SCC technology was made possible by the much

earlier development of super plasticisers for concrete. SCC has now been taken up with


21

enthusiasm across Europe, for both site and precast concrete work. Practical application has

been accompanied by much research into the physical and mechanical characteristics of SCC

and the wide range of knowledge generated has been sifted and combined in this guideline

document.

Self-consolidating concrete (SCC) is a relatively recent development in concrete

technology; it was first introduced in Japan in the late 1980‟s (3). However, it has been

predicted that within the next decade, SCC would replace a large portion of normal concrete

(4, 5), especially in developed countries. SCC has been generating significant interest and its

usage is gaining momentum in various projects worldwide. It is a highly flowable yet stable

concrete that can easily flow and consolidate, even in congested sections or complicated

formwork, with little or no vibration and without undergoing considerable segregation or

bleeding. SCC is usually produced using available conventional concrete materials. Its

mixture proportions are based on creating high flow ability while preserving a low

water/cementitious materials ratio. This can be achieved through the use of high-range water

reducing admixtures (HRWR) often in conjunction with rheology-modifying admixtures to

ensure the stability and homogeneity of the mixture. The advantages of SCC over

conventionally vibrated normal concrete (NC) include reducing noise on construction sites

and faster placement, thus increasing pour heights. Moreover, SCC insures improved finish,

hence reducing surface remedial costs and minimising wear and tear on formwork.

A substantial portion of the research performed on SCC was dedicated to its

rheological and hardened properties. Nagai et al. (6) studied the use of super workable

concrete in thin walled pre-stressed precast concrete members. Their study showed an

exceptional capacity of SCC to fill voids in heavily reinforced sections as thin as 60 mm with

no significant segregation and no deleterious effects on durability. Research was also

conducted on the compatibility of SCC with NC in sandwiched construction as a mean to


22

reduce cost (7). It was found that when casting SCC in congested areas and NC elsewhere in

a sandwiched manner, members behave satisfactorily.

Limited studies investigated the structural performance of SCC in congested members

compared to that of normal concrete (NC) (8, 9) and no study dedicated to the seismic

performance of SCC was accessible in the open literature. Persson (10) performed a

comparative study on NC and SCC to conclude that for similar concrete strength, both

concrete types behave similarly in terms of modulus of elasticity, creep and shrinkage.

However, the relatively lower coarse aggregate content in SCC may result in lower

contribution to the shear resistance produced by aggregate interlock. The study performed by

Schiessl and Zilch (11) confirmed such behaviour through a monotonic test. Using roughness

measurements, they found that crack surfaces of SCC were smoother than those of NC and

that at a similar normal stress across the crack, SCC specimens exhibited lower shear stress

resistance. This behaviour could be a concern, especially in the case of seismic loading.

For instance, moment-resisting frames (MRF‟s) usually contain congested areas of

reinforcement. Such frames would be among the applications most benefiting from SCC.

Nevertheless, the nature of reversed loading of MRF‟s in the event of an earthquake and the

resulting plastic hinging would impose cautiousness when SCC is used in such applications.

Although, SCC has been used in several buildings such as the Millennium Point Building in

Birmingham, New Zealand (4) without reported problems, investigations on the behaviour of

SCC under cyclic loading are needed for a wide implementation of this material in

earthquake-resistant structures.

Several recent earthquakes demonstrated that beam-column joints are vital elements

in keeping structural integrity. Joints failures and other types of non-ductile failures were a

major focus of the testimony of Thomas D. O‟Rourke (12) to the U.S. House of


23

Representatives Committee on Science regarding lessons to be learned from earthquake

events in major cities. In this research, the behaviour of SCC beam-column joints under

reversed cyclic loading is investigated and compared to that of NC beam-column joints, and

the use of SCC in structural frames is discussed.

2.1 Application Area

SCC may be used in pre-cast applications or for concrete placed on site. It can be

manufactured in a site batching plant or in a ready mix concrete plant and delivered to site by

truck. It can then be placed either by pumping or pouring into horizontal or vertical

structures. In designing the mix, the size and the form of the structure, the dimension and

density of reinforcement and cover should be taken in consideration. These aspects will all

influence the specific requirements for the SCC. Due to the flowing characteristics of SCC it

may be difficult to cast to a fall unless contained in a form. SCC has made it possible to cast

concrete structures of a quality that was not possible with the existing concrete technology.

2.2 Requirements

SCC can be designed to fulfil the requirements of EN 206 regarding density, strength

development, final strength and durability. Due to the high content of powder, SCC may

show more plastic shrinkage or creep than ordinary concrete mixes. These aspects should

therefore be considered during designing and specifying SCC. Current knowledge of these

aspects is limited and this is an area requiring further research. Special care should also be

taken to begin curing the concrete as early as possible. The workability of SCC is higher than

the highest class of consistence described within EN 206 and can be characterised by the

following properties:

Filling ability


24

Passing ability

Segregation resistance

A concrete mix can only be classified as Self-compacting Concrete if the

requirements for all three characteristics are fulfilled.

2.3 Properties

Self-compacting concrete produces resistance to segregation by using mineral fillers

or fines, and using special admixtures. Self-consolidating concrete is required to flow and fill

special forms under its own weight, it shall be flowable enough to pass through highly

reinforced areas, and must be able to avoid aggregate segregation. This type of concrete must

meet special project requirements in terms of placement and flow.

Self-compacting concrete with a similar water cement or cement binder ratio will

usually have a slightly higher strength compared with traditional vibrated concrete, due to the

lack of vibration giving an improved interface between the aggregate and hardened paste.

The concrete mix of SCC must be placed at a relatively higher velocity than that of

regular concrete. Self-compacting concrete has been placed from heights taller than 5 meters

without aggregate segregation. It can also be used in areas with normal and congested

reinforcement, with aggregates as large as 2 inches.

2.4 Self-Compacting Concrete Uses

Self-compacting concrete has been used in bridges and even on pre-cast sections. One

of the most remarkable projects built using self-compacting concrete is the Akashi-Kaikyo

Suspension Bridge. In this project, the SCC was mixed on-site and pumped through a piping

system to the specified point, located 200 meters away. On this particular project, the


25

construction time was reduced from 2.5 years to 2 years. This type of concrete is ideal to be

used in the following applications:

Areas with high concentration of rebar and pipes/conduits

Columns

Drilled shafts

Earth retaining systems

Self Compacting Concrete Benefits

Using self-compacting concrete produce several benefits and advantages over regular

concrete. Some of those benefits are:

Accelerates project schedules.

Allows for easier pumping procedure.

Allows for innovative architectural features.

Bond to reinforcing steel.

Fast placement without vibration or mechanical consolidation.

Flows into complex forms.

Improved constructability.

Improved structural Integrity.

It is recommended for deep sections or long-span applications.

Labor reduction.

Lowering noise levels produced by mechanical vibrators.

Minimizes voids on highly reinforced areas.

Produces a uniform surface.

Produces a wider variety of placement techniques.

Produces superior surface finishes.


26

Reduces equipment wear.

Reduces skilled labor.

Superior strength and durability.

2.5 Factors Affecting Self Compacting Concrete

Using self-compacting concrete must not be used indiscriminately. These factors can

affect the behavior and performance of self-compacting concrete:

Hot weather

Long haul distances can reduce flowability of self-compacting concrete.

Delays on job site could affect the concrete mix design performance.

Job site water addition to Self-Compacting Concrete may not always yield the

expected increase in flowability and could cause stability problems.

2.6 Self-Compacting Concrete Special Considerations

Self-compacting concrete can have benefits and will shorten the construction time.

However, special attention should be focused on:

Full capacity mixer of self-compacting concrete might not be feasible due to potential

spillage along the road, producing environmental and contamination hazards.

Formwork should be designed to withstand fluid concrete pressure that will be higher

than regular concrete.

Self-Consolidating Concrete may have to be placed in lifts in taller elements.

Production of SCC requires more experience and care than the conventional vibrated

concrete.

Self-consolidating concrete can add up to $50 per yards to your construction costs.

This cost will vary among ready-mix concrete producers.


27

CHAPTER 3: CONCEPT OF SFRSCC

Beam column joint is one of the most vulnerable areas in the case of reinforced

concrete framed structure. The congestion of steel reinforcement in the joints often leads to

poor inadequate strength and ductility of the joint. One of the possible methods of

overcoming this problem is by making use of self-compacting concrete in place of usual

concretes. Also from the literature it is noted that addition of steel fibers to cementitious

materials improves many of the engineering properties like tensile and flexural strength,

Energy absorption capacity and ductility and fracture toughness. Considering this, an attempt

has been made to study the effect of steel fibers on the strength and behaviour of self-

compacting concrete beam – column joints.

3.1 Effect of Fibers Utilized With Concrete

Fiber reinforced concrete is a composite material comprised of Portland cement,

aggregate, and fibers. Normal unreinforced concrete is brittle with a low tensile strength and

strain capacity. The function of the irregular fibers distributed randomly is to fill the cracks in

the composite. Fibers are generally utilized in concrete to manage the plastic shrink cracking

and drying shrink cracking. They also lessen the permeability of concrete and therefore


28

reduce the flow of water. Some types of fibers create greater impact, abrasion and shatter

resistance in the concrete. Usually fibers do not raise the flexural concrete strength. The

quantity of fibers required for a concrete mix is normally determined as a percentage of the

total volume of the composite materials. The fibers are bonded to the material, and allow the

fiber reinforced concrete to withstand considerable stresses during the post-cracking stage.

The actual effort of the fibers is to increase the concrete toughness.

3.2 Applications

During recent years, steel fiber reinforced concrete has gradually advanced from a

new, rather unproven material to one which has now attained acknowledgment in numerous

engineering applications. Lately it has become more frequent to substitute steel reinforcement

with steel fiber reinforced concrete. The applications of steel fiber reinforced concrete have

been varied and widespread, due to which it is difficult to categorize. The most common

applications are tunnel linings, slabs, and airport pavements. Many types of steel fibers are

used for concrete reinforcement. Round fibers are the most common type and their diameter

ranges from 0.25 to 0.75 mm. Rectangular steel fibers are usually 0.25 mm thick, although

0.3 to 0.5 mm wires have been used in India. Deformed fibers in the form of a bundle are also

used. The main advantage of deformed fibers is their ability to distribute uniformly within the

matrix. Fibers are comparatively expensive and this has limited their use to some extent.

3.3 Properties

Below are some properties that the use of steel fibers can significantly improve:

Flexural Strength: Flexural bending strength can be increased of up to 3 times more

compared to conventional concrete.

1) Impact Resistance: Greater resistance to damage in case of a heavy impact.


29

2) Permeability: The material is less porous.

3) Abrasion Resistance: More effective composition against abrasion and spalling.

4) Shrinkage: Shrinkage cracks can be eliminated.

5) Corrosion: Corrosion may affect the material but it will be limited in certain areas.

6) Fatigue Resistance: Almost 1 1/2 times increase in fatigue strength.

3.4 Limitations of Steel Fiber Reinforced Concrete

Steel Fibers used for Concrete Reinforcment

Though steel fiber reinforced concrete has numerous advantages, it has certain

concerns that are yet to be resolved completely.

There are complications involved in attaining uniform dispersal of fibers and

consistent concrete characteristics.

The use of SFRC requires a more precise configuration compared to normal concrete.

Another problem is that unless steel fibers are added in adequate quantity, the desired

improvements cannot be obtained.

However, as the quantity of fibers is increased, the workability of the concrete is

affected. Therefore, special techniques and concrete mixtures are used for steel fibers. If

proper techniques and proportions are not used, the fibers may also cause a finishing

problem, with the fibers coming out of the concrete


30

CHAPTER 4: LITERATURE REVIEW

4.1 Self-Compacting Concrete

Ozawa et al. (1989) focused on the influence of mineral admixtures, like fly ash and

blast furnace slag on the flowing ability and segregation resistance of self-compacting

concrete. They found out that on partially replacement of OPC by fly ash and blast furnace

slag the flowing ability of the concrete improved remarkably. He concluded that the best

flowing ability and strength characteristics 10-20% of fly ash and 25- 45% of slag cement by

mass.

Domone and His-Wen (1997) performed a slump test for high workability concrete. A

beneficial correlation between the slump values and flow was obtained from the laboratory

test. It showed satisfying value of the slump flow.

Bui et al. (2002) discussed a speedy method in order to test the resistance to

segregation of Self-compacting concrete. Extensive test programme of SCC with different

water-binder ratios, paste volumes, combinations between coarse and fine aggregates and

various types and contents of mineral admixtures was carried out. The test was helpful in

concluding the method along with the apparatus used for examining the segregation

resistance of SCC in both the directions (vertical and horizontal).


31

Xie et al. (2002) presented the preparation technology of high strength self-

compacting concrete (SCC) containing ultrapulverised fly ash (UPFA) and superplasticizer

(SP).Various parameters of concrete were selected namely good workability, high mechanical

properties and high durability and SCC was developed. There was low slump loss in the fresh

SCC mixture. The workability of high strength SCC containing UPFA and SP can be

evaluated by the method of combining slump flow and L-box test. Slump flow was 600- 750

mm. Flow velocity of L-box test was 35-80 mm/sec

Lachemi and Hossain (2004) presented the research on the suitability of four types of

Viscosity Modifying Agent (VMA) in producing SCC. Fresh and hardened properties of SCC

were studied by adding different VMA to SCC. The deformability through restricted areas

can be evaluated using v-funnel test. In this test, the funnel was filled completely with

concrete and the bottom outlet was opened, allowing the concrete to flow out. The time of

flow from the opening of outlet to the seizure of flow was recorded. Flow time can be

associated with a low deformability due to high paste viscosity, higher inter particle friction

or blockage of flow. Flow time should be below 6 sec for the concrete to be considered as

SCC. All the mix performed well with no significant segregation and jamming of aggregate

was noticed.

Cengiz (2005) used fly-ash with SCC in different proportional limit of 0%, 50% and

70% replacement of normal Portland cement (NPC). He investigated the strength properties

of self compacted concrete prepared using HVFA (high volume fly ash). Concrete mixtures

made with watercementitious material ratios ranged from 0.28 to 0.43 were cured at moist

and dry curing conditions. He investigated the strength properties of the mix and developed a

relationship between compressive strength and flexural tensile strength. The study proved

that it is possible to convert an RCC (zero slump) concrete to a workable concrete with the

use of suitable super plasticizer.


32

Ferrara et al. (2006) evaluated the HLSCC for all the basic properties namely

flowability, segregation resistance ability and filling ability of fresh concrete. The tests of

slump flow (for measuring of flowability) and the time which is required to reach the 500 mm

of slump flow (S) (for measuring of segregation resistance ability) of HLSCC satisfied the

expected capacity level in all mixes, the time is noted which is required to completely flow

through V-funnel (S) (for measuring of segregation resistance ability) only satisfied the level

in most of the LC mixed concrete (mix no. 2-4) and one of mixed concrete (mix no. 6)

Kumar (2006) reported the history of SCC development and its basic principle,

different testing methods to test highflowability, resistance against segregation, and passing

ability. Different mix design methods using a variety of materials has been discussed in this

paper, as the characteristics of materials and the mix proportion influences self-compact

ability to a great extent, also its applications and its practical acceptance at the job site and its

future prospects have also been discussed. Orimet test was performed, the more dynamic

flow of concrete in this test simulates better the behavior of a SCC mix when placed in

practice compared with the Slump-flow variation. The Orimet/J-ring combination test shows

great promise as a method of assessing filling ability, passing ability and resistance to

segregation

Sahmaran et al. (2007) presented a paper on study of fresh and mechanical properties

of a fibre reinforced self-compacting concrete incorpating high-volume fly ash in mixtures

containing fly ash. Fifty percent of cement by weight was replaced with fly ash. It was found

that the slump flow diameters of all mixtures were in the range of 560-700 mm which was in

acceptable range and the slump flow time was recorded to be less than 2.9 seconds.

Khatib (2008) investigated the properties of selfcompacting concrete prepared by

adding fly ash (FA). FA was used as a replacement for Portland Cement (PC). PC was


33

replaced 0-80% by fly ash. For all the mixes water binder ratio was maintained as 0.36.

Strength properties as well as the workability, shrinkage, absorption and ultrasonic pulse

velocity were studied in this research. From the observations it was concluded that 40%

replacement of FA resulted in strength of more than 65 N/mm2 at 56 days. On increasing the

amount of fly ash the high absorption values were obtained and absorption of less than 2%

was exhibited.

Grdic et al. (2008) presented the properties of self compacting concrete, mixed with

different types of additives: silica fume and fly ash. L-box test was used to assess the passing

ability of SCC to flow through tight openings including spaces between reinforcing bars and

other obstructions without segregation or blockage. L- Box has arrangement and the

dimensions by difference with the height of the horizontal section of the box, these three

measurements are used to calculate the mean depth of concrete as h2 mm. The same

procedure was used to calculate the depth of concrete immediately behind the gate h1 mm.

The passing ability was calculated from the following equation:

Pa=h2/h1

Where;

Pa is the passing ability and the value of Pa ranged between 2-10 mm

h1 and h2 are the height in mm at near and far end of passing ability respectively

Miao (2010) conducted a research on developing a SCC with cement replacement up

to 80% in all the mixes and examining its fresh properties. Result show that the fly ash acts as

a lubricant material; it does not react with super plasticizer and produce a repulsive force and

the super plasticizer may only act on the cement. As a result, the larger the amount of fly ash

contained, lesser the super plasticizer needed.


34

Heba (2011) presented an experimental study on SCC with two cement contents; the

work involved three types of mixes, the first considered different percentages of fly ash, the

seconds used different percentages of silica fumes and the third used mixtures of fly ash and

silica fume. It was concluded that higher the percentages of fly ash the higher the values of

concrete compressive strength until 30% of FA, however the higher values of concrete

compressive strength is obtained from mix containing 15% FA.

4.2 Steel Fiber Reinforced Self-Compacting Concrete

Sable and Rathi (2012) in their research explored the utilization of different steel

fibres with various aspect ratios in structural concrete to upgrade the mechanical properties of

self-compacting concrete. The study focuses on investigation of the properties of SCC with

and without fibres, and also assesses the effect of fly ash replacement on the rheological

properties of FRSCC.

Two different aspect ratios of steel fibres, i.e., 50 and 80 with volume fraction 2.5%

are studied in making the SCC mixes. A 30% replacement of cement with fly ash is studied

with constant water powder ratio of 0.408. The targeted strength is M30. This examination

was done by carrying out a few tests like the workability tests of SCC, compressive strength

test, tensile and flexural tests. The examination demonstrates that it is conceivable to use SCC

with fly ash and fibres as the fresh properties of mixes satisfy EFNARC conditions. The

hooked end and crimped fibres have good bond in the matrix resulting in better strength.

Additionally the use of fly ash in SCC enhances microstructure of solid that is likely to

improve all the mechanical properties of the mix.

Rao and Ravindra (2010) performed an examination on steel fibres reinforced self-

compacting concrete with steel fibres of different aspect ratios and different volume fractions.

Fresh and hardened properties of the concrete were studied, and the change in ultimate


35

strength was found. Results acquired from the majority of the mixes fulfill the lower and

maximum cut-off points proposed by EFNARC. The results of this investigation show that

optimum volume fraction and aspect ratio of fibres for good performance regarding strength

was found to be 1% and 25 respectively. They also concluded that using high volumes of fly

ash increases the workability characteristics of SCC mixtures.

Kamal, Safan and Etman (2014) performed tests on SCC to study their mechanical

properties and determine the optimum dosage of both steel and polypropylene fibres content

to be used in SCC to satisfy the workability conditions. The effective optimum percentage for

steel and polypropylene fibres was found to be 0.75% and 1% of cement content respectively.

It was also found that addition of these fibres increases the compressive strength, reduces the

bleeding, and increases the impact resistance and further leads to more ductile failure pattern

with the appearance of cracks prior to failure.

Khaloo, et al (2014) studied the mechanical performance of SCC reinforced with steel

fibres. They studied the effect of steel fibres on fresh properties of concrete, compressive

strength, splitting tensile strength, flexural strength, and flexural toughness of SCC

specimens. Different steel fibres volume fractions were studied, and reference mixes

considered were of strength 40MPa and 60MPa. Results showed that with addition of 2%

steel fibres workability reduces far below the minimum limits specified by EFNARC.

The presence of steel fibres increased the splitting tensile strength and flexural

toughness of the SCC specimens in low fibres volume, and it also showed that beams made

with medium strength SCC had more flexural toughness compared to beams made with high

strength SCC

Sahmaran, et al (2005) carried out an experimental program to investigate the effect

of fibres on SCC. In their work they considered two different types of steel fibres. The


36

authors concluded that by using considerable fibres inclusion i.e., 60kg/m3 it is possible to

accomplish self compaction. All mixes considered had good flow-ability characteristics. The

use of a commercial super plasticizer named ‗Smart flow„proved to be economical also. This

work also states that to get high workability and to retain that workability with the inclusion

of fibres, the amount of paste in the mix should be increased and this gives better dispersion

of fibres also.

Sahmaran, et al (2007) made a study on fresh and mechanical properties of fibre

reinforced self compacting concrete incorporating high volume fly ash. Suitable super

plasticizer and VMA were used to get a stable mix. Compressive strength, splitting tensile

strength and ultrasonic pulse velocity of the concrete were studied for the hardened

properties. The results of this work show that in spite of reduction in strength of concrete it is

possible to produce FRSCC incorporating high-volume fly ash with 50% replacement of

cementatious material. There is also increase in workability characteristics due to more paste

content in the mix. This work also concludes that fibres geometry affects the properties of

SCC mixes both in fresh and hardened states.

Deeb, Ghanbari and Karihaloo (2012) made a study on Self compacting high and

ultra-high performance concretes and the steps taken to develop them are briefly enlisted in

this work. Their main aim was to research and report how the mixture of solids and liquids

and the type of chemical admixture to be selected for developing concrete with self-

compatibility which ensures right flowing and passing capacity even with the involvement of

different types of steel fibres. The plastic viscosity of thus produced mixtures was estimated

by a simple micromechanical procedure explained briefly in their paper. Their work

concludes that it is successfully possible to attain self-compaction for high and ultra-high

performance concrete mixes with good flow-ability and no segregation. A good paste content

ensures good mix and distribution of fibres. Steel fibres of 30mm length and 0.55mm


37

diameter with crimped ends showed an all over good performance compared to other long

fibres used in this experiment.

It was also found that additional improvements could be made to mixes with fibres by

adjusting the type and amount of Super plasticizer

Frazao, et al (2015) investigated the durability aspect of steel fibre reinforced SCC.

The mechanical properties were also assessed. Steel fibres to the extent of 60kg/m3 were

used and this did not affect the self compaction characteristics of SCC i.e., it was a stable mix

with good flowing and passing ability. Two mixes were studied with and without fibres. This

work concludes that concrete mixes with steel fibres has good resistance to carbonation,

diffusion coefficient remained unchanged for both the mixes, inclusion of steel fibres showed

63% less electrical resistivity compared to plain SCC. Air penetrability and water absorption

were same for both the mixes. Post-cracking flexural resistance and the energy absorption

increased with addition of fibres. Corrosion of steel fibres could induce cracking in concrete

leading to decreased tensile strength, but this is only in case of extreme aggressive

environment.

Pajak and Ponikiewski (2013) made a detailed study on flexural behavior of SCC with

straight and hooked end steel fibres. Different volume fractions of steel fibres were studied

and compared to normal vibrated concrete. RILEM TC 162- TDF and EN 14651 were

referred for all the laboratory tests conducted. They determined that flexural tensile strength

could be described with same formulas for both steel fibres in SCC and steel fibres in normal

concrete. Increase of fibres percentage increased the flexural strength and fracture energy,

and also increased with fibres dosage. From this work it was concluded that the flexural

behavior of SCC is comparable with normally vibrated concrete and the increase of fibres

dosage increases the pre-peak and post-peak parameters of SCC.


38

Syal, Goel and Bhutani (2013) used hybrid fibres i.e., steel and polypropylene fibres

in different combinations and studied their effects on the workability and compressive

strength parameters of SCC. Their study consisted of three hybrid mixes with 0.5% volume

fraction of fibres. The materials used were relevant to the Indian Standard Specifications. The

test procedure for workability was fulfilled according to the requirements of EFNARC-2005.

From their test results it was concluded that usage of steel fibres increases the overall strength

and the polypropylene fibres, due to its light weight, is helpful in optimizing the self-weight

of SCC.

Ding et al. (2009) in their experimental work proposed suitable fibre types and fibre

dosages for high performance SCC. They made different series of experiments to evaluate the

influences of fibres on the mixes and reported that combination of steel fibres and PP-fibres

(i.e cocktail fibres or hybrid fibres) gives optimal fibre reinforcement for self-compacting-

high-performance-concrete

Aslani and Nejadi (2013) conducted both experimental and analytical studies on SCC

using steel fibres, polypropylene fibres and hybrid fibres where they obtained information

about the mechanical properties and also other relationship models which predict the strength

of the mixes. The results of this study concluded that the compressive strength and modulus

of elasticity of hybrid fibres based SCC are higher than those having steel fibres and

polypropylene fibres alone. The tensile strength and modulus of rupture of SCC mixes with

steel fibres only is higher compared to all other mixes.

Mazaheripour, et al (2011) studied lightweight self compacting concrete having

polypropylene fibres. The fresh and hardened properties of the mixes were studied. It was

found that the lighter the concrete more self compaction takes place; in this case the concrete

was lightened by 75% of normal weight which increased the fresh properties massively.


39

Increasing the percentage of polypropylene fibres reduced the slump which can be

maintained by the use of super plasticizer to a certain extent. With the optimum usage of

these fibres it was found that there is no increase in compressive strength but increased

tensile strength and flexural strengths.

Suresh Babu, et al (2008) developed a standard grade self-compacting concrete of mix

M30 in order to produce fibres reinforced self-compacting concrete using different mineral

admixtures of Fly Ash, GGBS and a combination of both in suitable proportions. Studies

were conducted on the mechanical behavior like stress-strain properties and modulus of

elasticity. An equation relating Compressive Strength (fck) and Modulus of Elasticity (Ec)

was proposed for plain SCC and GFRSCC mixtures as Ec = 4700 √fck and Ec =5700 √fck

respectively. An increase of 21.5% in the value of modulus of elasticity was observed with

GFRSCC mix. Toughness or energy absorption capacity of GFRSCC mixture is improved by

40% compared to plain SCC mix, whose ductility has improved by over 21% due to the

addition of 0.6kg/m3 of glass fibres to SCC mix. The investigations have been further

extended for the study of application in flexure by casting and testing under reinforced SCC

and GFRSCC beams, and it was found that load carrying capacity of GFRSCC increased

from 7.5% to 20%.

Seshadri and Srinivasa (2005) carried out an experimental investigation on glass

fibres reinforced self compacting concrete and suggested an optimum percentage of fibres to

be used to get the enhanced mechanical properties such as compressive strength, split tensile

strength and flexural strength while satisfying the fluidity characteristics like flow-ability,

filling-ability, passing ability and resistance to segregation. The following conclusions were

drawn from this report:


40

As compared with conventional concrete the glass fibres reinforced SCC gives the

higher strengths on long duration.

The mechanical properties of glass fibres reinforced SCC are in accordance with the

expected trends in conventional glass fibres reinforced concretes.

Seshadri and Srinivasa (2006) presented an experimental investigation on the

properties like workability and strength of glass fibres reinforced self-compacting concrete,

using lowest possible water powder ratio in the development of SCC mixes. They concluded

that the mechanical properties of glass fibres reinforced SCC of grades M50, M55, M60 and

M65 are in accordance with the expected trends in conventional glass fibres reinforced

concretes

Qadi and Al-Zaidyeen (2014) investigated the effect of different specimen shape on

mechanical properties of Polypropylene fibres reinforced SCC exposed to elevated

temperature (2000 -6000C). They studied different shapes of specimen i.e. cylindrical and

cubical specimens which were subjected to 2000 -6000C temperature for a duration of 24

hours. The thermal shock induced by cylindrical specimens caused severe damage to the

concrete and lead to reduction of compressive strength. This lead to a conclusion that shape

of the specimen affects the mechanical properties under elevated temperatures. The addition

of polypropylene fibres enhances the residual strength and fracture energy of concrete

specimens when subjected to thermal shock. The experimental procedure was carried out

with constant water to powder ratio of 0.32 and the fibres were varied with volume fraction

0%, 0.05%, 0.10% and 0.15%. Short PP fibres of 19mm length were used in this experiment.

The specimens were cast and cured for 89 days in water at 200C and then tested at different

elevated temperatures and heating period. The samples later were cooled down to room

temperature and tested for compressive strength. Their study concluded that the use of


41

polypropylene fibres does not affect the compressive strength upto 2000 – 4000C but when

the temperature is increased to 6000C the compressive strength of the specimens is affected.

The optimum percentage of polypropylene fibres to be used for cylindrical specimen

should be 0.05% and for cubical specimens it is 0.10% so that the compressive strength

increases and provides fire resistance. The cubical specimens showed a better compressive

strength than cylindrical specimens at elevated temperatures

Sabry (2013) made an extensive investigation on the properties and meso-structural

characteristics of linen fibre reinforced self-compacting concrete in slender columns. Their

experimental work consisted of 2 – 4 kg/m3 of linen fibres (30mm long), and used dolomite

as coarse aggregate. The w/p ratio and the percentage of high range water reducers were

constant for all mixes. Three mixes tested were plain SCC, and SCC with moderate and

maximum content of fibres. Fresh concrete tests were carried out according to EFNARC

standards. To assess the hardened properties the method used by Torrijos et al., was

implemented without change. The following conclusions can be drawn from this article: The

use of fibres reduces the workability but it is still in range recommended for SCC. The

compressive strength was improved by 8.3% and split tensile strength was improved by

17.6% at 2kg/m3 addition of fibres. The meso-structural analysis showed that the hardened

properties did not vary significantly along the height of columns. The aggregate distribution

was slightly more homogeneous in case of LFRSCC, and the variation of fibres density along

the height of columns was relatively high.

Mounir et al (2013) extended their studies to study the possibility of producing fibres

recycled self compacting concrete (FRSCC) using crushed red brick and crushed ceramic as

coarse aggregate. Polypropylene fibres were used in recycled self-compacting concrete to

improve fresh and hardened properties of this type of concrete. Polypropylene fibres volume


42

fraction varied from 0 to 1.5% of the volume of concrete with aspect ratio 12.5 and the fresh

properties of FRSCC were evaluated using slump flow, J-ring and V-funnel tests.

Compressive strength, Tensile strength, Flexural strength tests were performed in order to

investigate the mechanical properties. Results showed that the optimum volume fraction of

polypropylene fibres was 0.19% and 0.75% for the mixes with crushed red brick and ceramic

as coarse aggregate respectively. At optimum volume fraction of polypropylene fibres; the

mixes with crushed ceramic yields to improve in the compressive strength compared to the

mixes with crushed red brick as recycled aggregate.

At optimum dosage of polypropylene fibres, FRSCC mixes with crushed ceramic and

crushed red bricks yield to improve the compressive strength compared to the mixes with

crushed ceramic and crushed red bricks without fibres. This leads to improvement in the

tensile and flexural strength at optimum dosage of fibres. The use of recycled aggregates

reduces the overall compressive strength compared to dolomite mix of 36MPa at 28days.

4.3 The Particle-Matrix Model

By regarding the properties of the constituents and the interaction between them it is

to some extent possible to predict the workability of the fresh concrete. The particle matrix

model (PMM) is an attempt to describe the properties of the concrete by defining concrete as

a mix of two phases: the matrix phase and the particle phase. An illustration of this is shown

in Figure 2.1. The matrix phase is defined by The Norwegian Concrete Association as all

particles smaller than 0.125 mm, which includes water, cement, fines and additives. The

particle phase consists of all particles larger than 0.125 mm. These phases are respectively a

fluid material and a friction material. Although the matrix phase includes solid particles, they

are small enough to fill the voids and smear the larger particles, and can therefore be defined


43

as part of the fluid. For comparison, 1.0 mm will also be considered as a possible limit

particle-matrix phase, although this is not traditionally used

Figure 2.1: The particle-matrix model (Jacobsen et al, 2012)

By using different definitions for the classification of the phases the result of the

packing of particles will be completely different. When larger particles are considered part of

the matrix phase, the particle phase decrease consequently, see Figure below:

Figure 2.2: Example of variance in phase volumes because of differing limit for

particle matrix phase for the same composition of concrete

The phase that affects the concrete the most is referred to as the dominant phase. SCC

is always matrix dominated. This implies that the concrete has a large and viscous matrix


44

phase, which is necessary in order to get the flow ability needed for SCC. A disadvantage

with the PMM is that it does not help to predict the stability of the concrete

(NorskBetongforening, 2007).

The main purpose of the matrix is to fill the void in the particle phase. The matrix

surplus works as a lubricant that surrounds the particles to give the concrete flow able

properties. By calculating the void volume in the particle phase, and the surface area of the

particles, one can find the theoretical thickness, tc, of the matrix around each particle, as

shown in Figure below. This calculated parameter affects the flow ability of the concrete.

Figure 2.3: Matrix filling voids between particles (A) with matrix surplus (B)

(Jacobsen et.al, 2012)

The proportioning procedure of the PMM in brief consists of determining strength and

durability requirements of the actual concrete. This gives required water/binder-ratio binder

composition and minimum amount of binder. Then the main steps of the proportioning are:

Find and evaluate data for constituents: aggregate, cement and admixtures. The relevant data

is grading of particle size, density, void volume, water absorption, water/solid content for

admixtures and strength characteristics for cement/binder

The composition of aggregates regarding minimizing of void volume


45

Decide the composition of the paste and matrix from the requirements for strength

and durability, and necessary composition and volume of the matrix for the desired

consistency

Calculation of the theoretical recipe based on volume and mass

Trial mixture and correction

4.4 Bingham’s Model

A good way to describe the rheological properties of fresh concrete is to regard it as a

Bingham fluid. Bingham‟s model describes a fluid that needs a certain force applied to start

flowing (τ0) and has an approximately linear relation between continuing force and flow

ability, see Figure below:

Figure 2.4: Bingham's model (NorskBetongforening, 2007)

The yield stress is expressed by the formula:


46

Where:

τ is the yield stress, value in Pa

τ0 is the yield value, value in Pa

µ is the plastic viscosity, value in Pa*s

y is the rate of shear, value in 1/s

4.5 Compressible Packing Model

The worksheet „CPM-regneark‟, developed by Stein Are Berg (Berg, 2008), is used to

calculate properties for the mortars. It is based on the compressible packing model described

in de Larrard, 1999. The theory of the worksheet is explained by Berg (2008) and extended

by Skjolsvik (2010). The worksheet calculates several parameters. The ones used in this

thesis is tc, Ncs and Φm, where tc is the thickness of the lubricating matrix around each fibre.

Figure 2.5: Average thickness of matrix enveloping around fibre (Bui, Geiker and

Shah, 2003)


47

CHAPTER 5: MIX DESIGN OF SCC AND SFRSCC

5.1 Materials Required For SCC and SFRSCC

The basic ingredients used in Self-compacting concrete mixes are practically the same

as those used in the ordinary concrete. Following are the important materials used in SCC and

SFRSCC.

Cement:

In this experimental study, Ordinary Portland Cement of 53 grade is used. The cement

that is being used in this project complies with the requirements of the I.S. code. The

percentage of fines is less than 10% and the compressive strength of mortar cubes after 28

days curing has been found to be of the required value. The properties of cement are used in

experiments are shown in given below

Specific gravity of Cement = 3.15

Initial Setting Time of Cement = 160 min

Final Setting Time of Cement = 370 min

Percentage of Fines = 4.122%

Normal consistency of Cement = 30%

Compressive strength at 28 days = 53.67 Mpa

Coarse Aggregate:

The aggregate consist of crushed stone coarse aggregate of a maximum size of 16

mm. The properties of coarse aggregate are given below:

Fineness modulus of coarse aggregate = 7.24

Specific gravity of coarse aggregate = 2.78


48

Dry rodded bulk density of coarse aggregate = 1600 Kg/m3

Bulk density of loose coarse aggregate = 1494 Kg/m3

Fly ash:

Fly ash is used in mix because it has cementitious property and acting as a filler

material. It is important to increase the amount of pastry in SCC because it is an agent to

carry the aggregates. The Fly ash is used is of residue from the combustion of pulverized coal

collected by mechanical separators from the fuel gases of thermal plants.

Steel Fibre:

The hooked steel fibre having diameter 0.8 mm and length 60 mm were used for the

present study. The steel fibres are used in concrete to increase the tensile strength and reduce

the amount of cracks. A 0.5% of volume fraction is used to obtain SFRSCC. From the

experiments done by some investigators, it can be seen that the optimum volume fraction is

0.5%. Beyond this limit, there is in fact a reduction in the load carrying capacity of the

beams. The strength and ductility of fibre reinforced SCC specimen was found to be a

maximum in the case of specimen with volume fraction 0.5%.

Water:

Potable water which satisfy drinking standards was used for the concrete mixing and

curing

Super Plasticizer:

The super plasticizer was used to obtain the required workability. Super plasticizer is

essential for the creation of SCC. The job of Super Plasticizer is to impart a high degree of

flow ability and deformability, however the high dosages generally associate with SCC can


49

lead to a high degree of segregation. Conplast SP 430 is utilized in this project, which is a

product of FOSROC Company. Following table shows properties given by manufacturer:

Specific gravity = 1.222

Chloride content = Less than 0.05%

Air entrainment = Less than 1%

5.2 Mix Proportion of SCC and SFRSCC

In the present study, the various trial mixes are conducted from various mix design

methods of SCC. To obtain SCC which satisfies various tests like filling ability test, passing

ability test and segregation resistance test etc. on fresh SCC. After passing these tests, some

successful SCC mixes are arrived. From such successful mixes, choose final mix of

proportion after the cubes are cast and tested after 7 days and 28 days, it gives cube strength

at 28 days as 37.4 N/mm2 which is well above the mean target strength of M-30 concrete. So

final mix proportion of M-30 is

After getting mix proportions for SCC, to obtain SFRSCC, hooked steel fibres (0.5%

and 0.75% of volume fraction) are added in SCC mix proportion. Fibres may be used to

enhance the properties of SCC in the same way as for normal concrete.


50

5.3 Testing of SCC and SFRSCC

Figure 1: Comparison of Compressive Strength Test Result

Figure 2: Comparison of Split Tensile Strength Test Result

Figure 3: Comparison of Flexural Strength Test Result


51

In Beam-column joint, the column was reinforced with 4 numbers of 10 mm

diameters and the beam was provided with an equal amount of reinforcement of 2 numbers of

10 mm diameter bars at top and bottom. 6 mm diameter M.S. bars are used for transverse ties

in column and stirrups in beams. The reinforcement details are shown in figure below:

Figure 4: Details of specimen and reinforcement as per I.S. 13920:1993

All the specimens were tested in a Universal Testing Machine. The specimen was

mounted in a vertical position. A constant axial load equal to 20% of the theoretical axial

load capacity of the column was applied to keep the column in vertical position. A hydraulic

jack was used to apply the load at the free end of the beam. The increment of loading selected

was 1 KN. The beam was then loaded gradually up to 1KN, then unloaded to zero load and

reloaded to the next increment of load and this pattern of loading was continued for each

increment until failure. Other instrumentation used during test was Linear Variable

Differential Transducers to record the curvature of the beam near joint.


52

CHAPTER 6: EXPERIMENTAL PROGRAMME AND TEST RESULTS

The test set up is shown schematically as below. The joint assemblages are subjected

to axial load and reverse cyclic load. A constant column axial load is applied by means of

hydraulic jack mounted vertically to the loading frame to simulate the gravity load on the

column. One end of the column is given an external hinge support and other end is laterally

restrained by a roller support to get moment free rotation at both ends. The test is load

controlled and the specimen is subjected to an increasing cyclic load up to the failure.


53

Figure 5: Experimental Set Up

Beam-column joints can be isolated from plane frames at the points of contraflexure.

The beam of the current test unit is taken to the mid-span of the bay, while the column is

taken from the mid-height of one storey to the mid-height of the next storey. Two standard

beam-column joints (J1 and J3) were designed as per the current CSA A23.3-94 (1)

requirements with sufficient shear reinforcement in the joint area and in the hinging areas of

the column and beam. The column is 3000 mm high with cross-section dimensions of

250x400 mm. The beam‟s length is 1750 mm from the face of the column to its free end with

a crosssection of 250x400 mm. The longitudinal reinforcement used in the column is 14 M15

bars (M15 is equivalent to a 16.0 mm diameter bar) without splicing. The transverse

reinforcement in the column was two M10 closed rectangular ties. The ties are spaced at 80

mm inside the joint and along 500 mm above and below it (one sixth of the floor‟s height)

then spaced at 125 mm for the rest of the floor height. The top and bottom longitudinal

reinforcements of the beam are 6 M15 bars each. The transverse reinforcement of the beam is

M10 rectangular ties starting at 50 mm from the face of the column. The ties are spaced at 80

mm for the 800 mm adjacent to the column (equivalent to twice the beam depth) and then

spaced at 120 mm for the remaining 840 mm, ending at 60 mm from the free end of the


54

beam. The longitudinal rebar size and transverse reinforcement for the joint and hinging

zones confinement are code conforming. Reinforcement details for the tested specimens are

shown in Figure 1. NC and SCC were used to cast specimens J1 and J3, respectively.

Concrete mixture proportions for both specimens are shown in Table 1. No vibration was

used for casting the SCC specimen. Upon the release of the formwork, it was clear that the

specimen constructed with SCC had less surface irregularities in comparison with the one

made with NC in which the steel reinforcement was exposed at various locations despite the

use of vibration.


55

Figure 6: Reinforcement details for the specimens.


56

Table 1: Concrete mixture proportions for the tested specimens.

6.1 Design of Beam-Column Joint

The Five specimens of Beam-Column joints are designed according to I.S.

13920:1993. Out of five specimens two specimens are detailed as per I.S. 13920:1993 and

remaining three specimens are also detailed same but by replacing the stirrups at the joint

region by diagonal cross inclined bars provided at the two joint faces for confinement of the

joint. The column was reinforced with 4 numbers of 12 mm diameter HYSD bar and the

beam was provided with an equal amount of reinforcement of 2 numbers of 12 mm diameter

HYSD bars at top and bottom. 6 mm diameter MS bars were used for transverse ties in

columns and stirrups in beams. The reinforcement details are shown in figure below:


57

Figure 6: Reinforcement details as per I.S. 13920:1993 and diagonal cross inclined

bar

6.2 Description of Beam-Column Joint Specimen

There are five specimens of Beam-Column joint is to be casted. All specimens are

casted with M30 grade concrete. The description of specimens is shown in the following

table:

Table 2: Description of Beam-Column Joint Specimen

6.3 Testing of Specimen

All the specimens were tested in a Loading Frame of 1000 kN Capacity. The

specimen was mounted in a vertical position. A constant axial load equal to 20% of the

theoretical axial load capacity of the column was applied to keep the column in vertical


58

position. A hydraulic jack of capacity 10 tonne is used to apply the load at the free end of the

beam. To record the load precisely, a load cell is used. The increment of loading selected was

1 KN. The beam was then loaded gradually up to 1 KN, then unloaded to zero loads and

reloaded to the next increment of load, this pattern of loading was continued for each

increment until failure. The deflection at the point of loading during test was measured using

a dial gauge with a least count of 0.01 mm

6.4 Experimental Set Up

The joint assemblages are subjected to axial load and reverse cyclic load. One end of

the column is given an external hinge support and other end is laterally restrained by a roller

support to get moment free rotation at both ends. Cyclic loading is applied by 10 tonne

hydraulic jack, which is fixed on strong reaction floor. Reverse cyclic load is applied at 50

mm from free end of the beam portion. The test is load controlled and the specimen is

subjected to an increasing cyclic load up to the failure. To record loads precisely, load cells

are used.

6.5 Behaviour of Specimens

In all the specimens cracks appeared near the joint. In case of Beam-Column Joint

with conventional detailing diagonal cracks also occurred in the Beam-Column joint region.

As the loading is increased, additional cracks are formed. With further increase in loading,

the cracks propagated up to the beam. Specimens without fibres developed more and wide

cracks at the joint region. Specimens with fibres and cross inclined bars in joint region shows

very less diagonal cracks which are occurred in Beam-Column joints with conventional

detailing. A tested specimen is shown in the figures below:


59

Figure 7(a): Specimen 1


60

Figure 7(b): Specimen 2

Figure 7(c): Specimen 3

Figure 7(d): Specimen 4


61

Figure 7(e): Specimen 5

6.6 Test Setup and Procedure under Reversed Cyclic Loading

The beam-column joint specimens were tested under reversed cyclic loading applied

at the beam tip. The selected loading pattern is intended to cause forces that simulate high

levels of inelastic deformations that may be experienced by the frame during a severe

earthquake. The selected load history consisted of two phases. The first phase was load-

controlled followed by a displacement-controlled loading phase.

In the first phase of loading, two load cycles at approximately 10% of the estimated

strength of the specimen were applied to check the test setup and ensure that all data

acquisition channels were functioning properly. This was followed by two load cycles

reaching the concrete cracking load in the beam. These in turn were followed by two cycles

at the load causing initial yield of the bottom longitudinal steel bars in the beam. The

displacement at initial yield of the steel, δy, was recorded and used in the subsequent

displacement-controlled phase of loading.


62

The second phase of loading after first steel yield was displacement-controlled and

consisted of applying incremental multiples of the yield displacement, δy (previously

recorded at initial yield). Two load cycles were applied at each ductility level to verify the

stability of the specimen. The ductility level is expressed in terms of a ductility factor, µ,

which is defined as the ratio of the beam tip displacement, δ, to the displacement at first yield

of the principal steel reinforcement, δy. The test was stopped when the load carrying capacity

of the subassemblage dropped to about 50% of its maximum value.

The specimens were placed in the test rig to mimic a hinge support at the base of the

column and a roller support at the top part of the column. The roller support was created

using a 2 cm vertical slot which allowed vertical deformation in the column as well as the

transmission of the column‟s axial load from the hydraulic jack to the lower hinge support.

The cyclic load was applied at the beam tip using a loading ram through a greased pin

connection at an arm length of 1670 mm measured from the column face.


63

Figure 8: Load history for the reversed cyclic load


64

Figure 9: Test setup


65

CHAPTER 7: ANALYSIS OF TEST RESULTS AND DISCUSSION

The results obtained from test on beam-column joints at 14 days. Significant increase

in first crack load and ultimate load were found with the increase in fibre content. The

ultimate load is increases at 0.5% of fibres and the ultimate load is decreases at 0.75% of

fibres. Addition of fibres above 0.75% did not enhance the ultimate strength. This may due to

steel fibres at higher percentage of fibre content, which caused difficulty in compacting the

specimens.


66

Figure 10: Comparison of Result of Peak load


67

Figure 11: Comparison of Result of Deflection at Peak load

The load displacement plots for the NC (J1) and SCC (J3) specimens are shown in

Figures 4 and 5, respectively. For the NC specimen, the yield of the beam‟s longitudinal steel

was reached at an average beam tip load of 107 kN and the corresponding average yield

displacement was 28 mm (based on push up and pull down values), whereas for the SCC

specimen, the yield load was 104 kN at a displacement of 27 mm.


68

Figure 12: Load displacement relationship for NC specimen J1


69

Figure 13: Load displacement relationship for SCC specimen J3.

The onset of diagonal cracks in the joint area took place at a beam tip load of 60 kN

and 65 kN for specimens J1 and J3, respectively. Additional cracks appeared thereafter as

loading progressed at a uniform spacing, but remained within a very fine width throughout

the test. At a ductility factor of 2, the beam became extensively cracked along a distance

equal to its depth from the face of the column for both specimens. At a ductility factor of 3,

the SCC specimen started exhibiting lower load carrying capacity and this became clearer in


70

subsequent load cycles. For both specimens the column‟s axial load was maintained and the

joint areas were still intact, except the presence of fine diagonal cracks. The faster decline of

the load carrying capacity of the SCC specimen could be attributed to the fact that its lower

coarse aggregate reduced the contribution of friction due to aggregate interlock to the total

shear resistance mechanisms, especially at high levels of displacement. Final crack patterns

for the NC (J1) and the SCC (J3) beam-column joint specimens are shown in Figure 14 (a)

and (b), respectively.

Figure 14: Final crack pattern for (a) NC specimen (J1), and (b) SCC specimen (J4)


71

7.1 Load - Displacement Envelope Relationship

For each of the beam-column joint specimens, the envelope of the beam tip load-

displacement relationship is plotted in Figure 7. The SCC specimen (J3) had a comparable

capacity to that of the normal concrete specimen (J1) up to a displacement level of about 75

mm (corresponding to a 4.5% drift), which could be considered as structurally adequate.

Subsequently, the reserve strength of the SCC specimen was lower and a plastic hinge

formed in the beam. The maximum displacement ductility achieved by the NC specimen was

6 compared to 5 for the SCC specimen. It is worth mentioning that for both specimens, at the

same levels of joint shear input, the calculated joint deformations were comparable. In

addition, the beams‟ plastic hinges formed at equal distances from the column face for both

specimens.

Figure 15: Load-displacement envelopes for the tested specimens


72

7.2 Cumulative Dissipated Energy

The capability of a structure to survive an earthquake depends on its ability to

dissipate the energy input by the ground motion. The cumulative energy dissipated by the

beam-column joint specimens during the reversed cyclic load test was calculated by summing

up the energy dissipated in consecutive load displacement loops throughout the test. The

energy dissipated in a cycle is calculated as the area that the hysteretic loop encloses in the

corresponding beam tip load-displacement plot. Figure 8 shows a plot of the cumulative

energy dissipation versus displacement ductility factor for the NC specimen (J1) and the SCC

specimen (J3). Results show that the SCC joint had higher energy dissipation till a ductility

level of 3. Afterwards, the NC joint specimen showed higher energy dissipation capacity with

an overall 38% superiority.

Figure 16: Cumulative energy dissipated for the tested specimens


73

7.3 Secant Stiffness

Secant stiffness is evaluated as the peak-to-peak stiffness of the beam tip load-

displacement relationship. It is calculated as the slope of the line joining the peak of positive

and negative loads at each given cycle. The secant stiffness is an index of the response of the

specimen during a cycle and its strength degradation from one cycle to the following cycle.

Figure 9 shows plots of the secant stiffness for the NC and SCC beam-column joint

specimens versus the storey drift. The storey drift is calculated as shown in Figure 10 by

relating the subassemblage deformation in the test rig to the actual displaced frame case. An

examination of the plots indicates that the SCC specimen (J3) had higher initial stiffness.

After a drift angle of 2%, the NC standard specimen (J1) had higher stiffness up to the end of

the test. Nonetheless, the SCC specimen (J3) exhibited stable strength degradation up to

failure. The maximum drift achieved was 9.0% and 7.9% for specimens J1 and J3,

respectively.


74

Figure 17: Secant stiffness-displacement ductility factor for the tested specimens


75

Figure 18: Exterior beam-column subassemblages in (a) displaced frame and (b) test

rig


76

CHAPTER 8: CONCLUSION

Reversed cyclic loading tests were performed on full-scale beam-column joint

specimens to compare the performance of normal concrete and self-consolidating concrete in

moment resisting frames. Based on experimental observations and analysis of test results, the

following conclusions can be drawn:

Cracking pattern of the Specimen shows that Specimens are failed due to developing

cracks at the interface between beam and column.

Deflection at peak load is significantly increased with increase of fibre content.

Further studies are needed to investigate the behaviour of SCC under cyclic loading in

plastic hinging zones and to quantify aggregate interlock contribution mechanisms for

different coarse aggregate contents along with the effect of other mixture design

parameters.

It is seen that addition of steel fibre upto 0.5% in the core of Beam-Column joint,

there is increase in the ultimate load. On the other hand, 0.75% addition of steel fibre

shows decrease in ultimate load.

SCC beam-column joints have comparable load capacity to that of NC joints up to a

certain ductility level. At high ductility levels, SCC specimens may not maintain the

same capacity as NC specimens. While this behaviour could be attributed to the fact

that the lower coarse aggregate content in SCC reduced the contribution of the

aggregate interlock to the total shear resistance mechanism, further research is

required to fully understand this behaviour.

The performance of SCC under shear stress in the joint panel was comparable to that

of NC in terms of cracking and deformations.


77

The results shows that the specimen with 0.5% steel fibre and cross inclined bar gives

Optimum results compared to other Specimens.

The SCC beam-column joint specimen performed adequately in terms of the mode of

failure and ductility requirements, assuming that the expected minimum drift

requirement is 3%, as recommended in the literature for ductile frame buildings

The Specimen having joint region with cross inclined bar shows very less cracks in

the Beam-Column joint region due to adequate shear resisting capacity.

The tests for Compressive Strength, Flexural Strength and Split Tensile Strength of

various Specimens are performed.

All the specimens are failed by developing cracks at the interface between beam and

column

In the beam column joint region of the specimens to improve the ductility by using

cross inclined bars

To improve the strength and ductility of the joint by addition of steel fibres in the

SCC

Deflection and curvature at peak load of SCC are significantly increased with increase

of fibre content

By addition of steel fibre in the joint, the ultimate load carrying capacity was

increased.


78

BIBLIOGRAPHY

ACI 352R-02, 2002, “Recommendations for Design of Beam Column Connections in

Monolithic Reinforced Concrete Structures”, Joint ACI-ASCE Committee 352, Technical

Committee Document 352R-02, 37 p.

AlirezaKhaloo, Elias MolaeiRaisi, Payam Hosseini and HamidrezaTahsiri,, 2014

―Mechanical performance of self-compacted concrete reinforced with steel fibres,

Construction and Building Materials 51, 179-186.

Amir A. Mirsayah and NemkumarBanthia, “Shear strength of steel fiber reinforced

concrete”.ACI material Journal Sept.2002, pp. 476-479.

Arabi N.S. Al Qadi, Sleiman M. Al-Zaidyeen. 2014, ―Effect of fibres content and specimen

shape on residual strength of polypropylene fibre self-compacting concrete exposed to

elevated temperatures, Journal of King Daud university- Engineering sciences 26, 33-39.

B. Krishna Rao and Professor V. Ravindra, 2010 ―Steel Fibres Reinforced Self compacting

Concrete Incorporating Class F Fly Ash, International Journal of Engineering Science and

Technology

B.H.V. Pai, M. Nandy, A. Krishnamoorthy, P.K.Sarkar, C. PramukhGanapathy,

“Experimental Study On SelfCompacting Concrete Containing Industrial ByProducts”,

European Scientific Journal, April 2014 edition vol.10, No.12, pp.292-300.

Campion, M. J., and Jost, P., 2000, “Self Compacting Concrete- Expanding the Possibilities

of Concrete Design and Placement”, Concrete International, Vol. 22, No. 4, pp. 31-34.

Corley, W. G., 1995, “Ductility of Columns, Walls, and Beams-How Much is Enough?”,

American Concrete Institute, Proceedings of the Thomas Paulay Symposium on Recent


79

Developments in Lateral Force Transfer in Buildings, SP-157, La Jolla, California, pp. 331-

350

Cristina Frazao, Airees Camoes, Joaquim Barros and DefinaGoncalves, 2015, ―Durability of

steel fibres reinforced self compacting concrete. Construction and building materials 80, 155-

166.

CSA A23.3-94, 1994, “Design of Concrete Structures”, Canadian Standards Association,

Rexdale, Ontario, Canada, 209

Ding Y., Liu S., Zhang Y. and Thomas A. (2009). ―The investigation on strength and

flexural toughness of fibres cocktail reinforced self compacting high performance concrete,

Journal of construction and building materials.

FarhadAslani and ShamiNejadi, 2013, ―Self compacting concrete incorporating steel and

polypropylene fibres: Compressive and tensile strengths, moduli of elasticity and rupture,

compressive stress–strain curve, and energy dissipated under compression, Composites: Part

B.

G. Maariappan& R. Singaravadivelan, “Studies on Behaviour of Rcc Beam-Column Joint

Retrofitted with Basalt Fiber Reinforced Polymer Sheet”, Global Journal of Researches in

Engineering Civil and Structural Engineering, Volume 13 Issue 5 Year 2013.

H. Masaheripor, S. Ghanbarpour, S.H Mirmoradi and I. Hosseinpour, 2011 ―The effect of

polypropylene fibres on the properties of fresh and hardened lightweight self-compacting

concrete‖ , Construction and building Materials 25, 351-358.

Henderson, N., 2000, “Self compacting concrete at Millennium Point”, Concrete for the

Construction Industry, The Concrete Society, UK, April 2000, pp. 26-27.


80

Ho, D. W. S., Sheinn, A. M. M. and Tam, C. T., 2001, “The Sandwich Concept of

Construction with SCC”, Cement and Concrete Research, Vol. 31, No. 9. pp. 1377–1381.

K.R. Bindhu and K.P. jaya, “Performance of exterior beam column joint with cross inclined

bars,” Journal of engineering and applied sciences 3(7),591-597,2008.

Khayat, K. H., Paultre, P., and Tremblay S., 2001, “Structural Performance and in-Place

Properties of Self-Consolidating Concrete Used for Casting Highly Reinforced Columns”,

ACI Materials Journal, Vol. 98, No. 5, pp. 371-378.

Kishor S. Sable, Madhuri K. Rathi., 2012 ―Effect of Different Type of Steel Fibre and

Aspect Ratio on Mechanical Properties of Self Compacted Concrete, International Journal of

Engineering and Innovative Technology.

M.Pajak and T. Ponikiewski, 2013, ―Flexural behavior of self compacting concrete

reinforced with different types of steel fibres. Construction and building material 47, 397-

408.

Mounir M. Kamal, Mohamed A. Safan and Zeinab A. Etman , 2014 ―Mechanical Properties

of Self-compacted Fibres Concrete mixes. HBRC Journal.Tavel, P. 2007 Modeling and

Simulation Design. AK Peters Ltd.

Mustafa Sahmaran, AlperenYurtseven, and Ismail OzgurYaman (2005). Workability of

hybrid fibres reinforced self-compacting concrete, Journal of building and environment,

Elsevier Ltd., 40, pp. 1672-1677.

Mustafa Sahmaran, AlperenYurtseven, and Ismail OzgurYaman 2007 ―Study on fresh and

mechanical properties of Fibres reinforced self-compacting concrete incorporating high

volume fly ash.


81

N. Ganesan, P.V. Indira and Ruby Abraham, “Steel Fibre Reinforced High Performance

Concrete BeamColumn Joints Subjected To Cyclic Loading”, ISET Journal of Earthquake

Technology, Vol. 44, No. 3-4, Sept.-Dec. 2007, pp. 445–456.

Nagai, T., Kojima, T., and Miura, T., 1999, “Application of High Strength/Superworkable

Concrete to Thin-Wall Prestressed Concrete Products”, Magazine of Concrete Research, Vol.

51, No. 3, pp. 153- 162.

Nagamoto, N. and Ozawa, K., 1997, “Mixture Properties of Self-Compacting, High-

Performance Concrete”, Proceedings of the Third CANMET/ACI International Conference

on Design and Materials and Recent Advances in Concrete Technology, ACI SP 172, Kuala

Lumpur, Malaysia, pp. 627-637.

Nan Su.Kung-Chung Hsund, His-Wen Chai (2001), “A simple Mix Design Method for Self

Compacting Concrete”, Cement and Concrete Research, Vol.32, pp. 1799-1807.

Naveen Hooda, JyotiNarwal, Bhupinder Singh, VivekVerma, Parveen Singh, “An

Experimental Investigation on Structural Behaviour of Beam Column Joint”, International

Journal of Innovative Technology and Exploring Engineering (IJITEE) Volume-3, Issue-3,

August 2013, pp. 84-88.

O‟Rourke, T. D., 1999, “The Turkey, Taiwan, and Mexico City Earthquakes: Lessons

Learned”, Hearing of the Subcommittee on Basic Research U.S. House of Representatives

Committee on Science, October 20, 1999. Web address

http://www.eeri.org/Features/ORourke99/HTML/index.htm

Okamura, H (1997), “Self compacting high performance concrete” Concrete international,

July, PP. 50-54.

http://www.eeri.org/Features/ORourke99/HTML/index.htm


82

Okamura, H. and Ouchi, M (2003) “Self compacting concrete” Journal of advanced concrete

technology, Vol.1, No. 1, April, PP.5-15.

Park, R. and Paule ,T.”Reinforced concrete structures” John wiley, New York, 1975.

Paulay, T. 1989. “Equilibrium criteria for reinforced concrete beam column joint”. ACI

structural Journal, 86(11), pp. 635-643.

Persson B., 2001, “A Comparison Between Mechanical Properties of Self-Compacting

Concrete and the Corresponding Properties of Normal Concrete”, Cement and Concrete

Research, Vol. 31, No. 2, pp. 193-198.

R. Deeb, A. Ghanbari, B.L. Karihaloo, 2012, ―Development of self compacting high and

ultra high performance concretes with and without steel fibres, Cement and concrete

composites 32, 185-190.

S. Suchithra and R. Malathy, “Computational Analysis of Bending Properties of Self-

Compacting Concrete Reinforced With Steel Fibers, International Journal of Innovative

Research in Science, Engineering and Technology, Vol. 3, Issue 4, April 2014, pp. 93-99.

S.Subramanian and D. Chattopadhyay (2002), “Experiments for mix proportioning of Self

Compacting Concrete” The Indian Concrete Journal Jan.2002, pp. 13-19.

Schiessl, A. and Zilch, K., 2001, “The Effect of the Modified Composition of SCC on Shear

and Bond Behaviour”, Proceedings of the Second International Symposium on Self-

Compacting Concrete, Tokyo, Japan, RILEM Publications S.A.R.L., pp. 501-506.

SeshadriSekhar T. and Srinivasa Rao P. (2005). ―Studies on glass fibres self compacting

concrete, The master builder, pp.32-35.


83

SeshadriSekhar T. and Srinivasa Rao P. (2006). ―Experimental investigation of glass fibres

reinforced self-compacting concrete, Journal of technical and vocational education, Vol.22,

No.2, pp.20- 29.

Sonebi, M., Bartos, P., and Tamimi, A., 2001, “Flexural Response of Reinforced Beams Cast

with Self-Compacting Concrete”, Proceedings of the Second International Symposium on

Self-Compacting Concrete, Tokyo, Japan, RILEM Publications S.A.R.L., pp. 517-526.

Suresh Babu. T, Seshagiri Rao. M.V. and Ramseshu. D (2008) ―Mechanical Properties and

Stress-Strain Behaviour of Self Compacting Concrete with and without Glass Fibres, Asian

Journal of Civil Engineering Vol.9,No.5,pp457-472.

SyalTarun, Goel Sanjay, Bhutani Manish, 2013 ―Workability And Compressive Strength of

Steel Polypropylene Hybrid Fibre Reinforced Self-Compacting Concrete, International

journal for science and emerging technologies with latest trends, 6 (1): 7-13.

Veerendra Kumar and Mohammed Shamim, “Behaviour of reinforced concrete beam column

joint”. Oct 1999 pp. 207-214.

Veerendra Kumar and Mohammed Shamim, “Influence of beam reinforcement on exterior

beam column joint”.Journal of structural Engg.July 1999 pp. 123-127.

*****

STRENGTH AND BEHAVIOUR OF SCC AND SFRSCC EXTERIOR … · Airo International Research Journal Volume...

Documents

Transcript of STRENGTH AND BEHAVIOUR OF SCC AND SFRSCC EXTERIOR … · Airo International Research Journal Volume...