High Temperature Fatigue and Fatigue Damage Process of

Aggregate-Asphalt Mixes

by

Bor-Wen Tsai

Report to California Department of Transportation

University of California at BerkeleyInstitute of Transportation Studies

Pavement Research Center

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ACKNOWLEDGEMENTS

This report was partially funded through the Federal Highway Administration National

Cooperative Highway Research Program Project 9-20, Performance-Related Specifications for

Hot-Mix Asphalt Construction.

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Table of Contents

Table of Contents............................................................................................................................ v

List of Figures ............................................................................................................................... xv

List of Tables ......................................................................................................................... xxxviii

Introduction..................................................................................................................................... 1

1.1 Background ......................................................................................................................... 1

1.2 Research Objectives............................................................................................................ 6

1.3 Literature Review................................................................................................................ 7

1.3.1 History of Asphalt Concrete Fatigue Model Development ........................................ 7

1.3.2 Crack Initiation and Crack Propagation.................................................................... 10

1.3.3 High Temperature Fatigue Test ................................................................................ 12

1.3.4 Compound Strain-Based Fatigue Loading................................................................ 16

1.3.5 The Weibull Function ............................................................................................... 18

1.3.6 Cumulative Fatigue Damage Prediction ................................................................... 19

1.3.7 Full-Scale Accelerated Pavement Tests.................................................................... 20

1.3.8 Shift Factor................................................................................................................ 21

1.4 Research Organization ...................................................................................................... 25

2.0 Data Sources ..................................................................................................................... 27

2.1 WesTrack Project.............................................................................................................. 27

2.1.1 Track Characteristics ................................................................................................ 28

2.1.2 Mix Characteristics ................................................................................................... 28

2.1.3 Traffic ....................................................................................................................... 30

2.1.4 Temperature .............................................................................................................. 34

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2.2 CAL/APT HVS Project..................................................................................................... 35

2.2.1 Section 503RF........................................................................................................... 35

2.2.2 Trafficking Plan ........................................................................................................ 36

2.2.3 Multi-Depth Deflectometer (MDD).......................................................................... 38

2.3 Laboratory Test Data ........................................................................................................ 38

3.0 Test Plan, Specimen Preparation, and Test Setup............................................................. 43

3.1 Test Purpose...................................................................................................................... 43

3.2 Test Setup.......................................................................................................................... 44

3.2.1 Conventional Flexural Controlled-Strain Fatigue Test Setup................................... 44

3.2.2 Modified Flexural Controlled-Strain Fatigue Test Setup ......................................... 45

3.2.3 Instrumentation and Data Acquisition System ......................................................... 48

3.3 Specimen Preparation ....................................................................................................... 53

3.3.1 Gradation Curves of WesTrack ................................................................................ 53

3.3.2 Procedure of Specimen Preparation for WesTrack................................................... 54

3.4 Test Plan............................................................................................................................ 60

3.4.1 High Temperature Modified Flexural Controlled-Strain Fatigue Test ..................... 60

3.4.2 Temperature Susceptibility Fatigue Test with Conventional Setup ......................... 62

3.4.3 Fatigue Test with Various Gradation Types ............................................................. 62

3.4.4 Flexural Frequency Sweep Test................................................................................ 63

3.4.5 Varied-Strain Fatigue Test ........................................................................................ 64

3.4.6 Varied-Temperature Fatigue Test ............................................................................. 64

4.0 Fatigue Test Results and Analysis .................................................................................... 67

4.1 Background ....................................................................................................................... 67

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4.1.1 Interpretation of Weibull Curves .............................................................................. 68

4.1.2 Crack Initiation and Weibull Curves ........................................................................ 72

4.2 Fatigue Tests at 20oC ........................................................................................................ 75

4.3 Temperature Susceptibility Fatigue Test (Field) .............................................................. 92

4.4 Temperature Susceptibility Fatigue Test (Laboratory)..................................................... 94

4.5 High Temperature Flexural Controlled-Strain Fatigue Test ............................................. 95

4.6 Fatigue Test with Various Gradation Types ................................................................... 100

4.7 Pooled Fatigue Tests ....................................................................................................... 101

4.8 Conventional Fatigue Analysis for WesTrack Project.................................................... 102

4.8.1 Model Selection ...................................................................................................... 102

4.8.2 Mallows pC Statistic............................................................................................. 103

4.8.3 Data Description ..................................................................................................... 104

4.8.4 A Regression Example: Coarse Gradation ............................................................. 104

4.8.5 Regression Analysis Results ................................................................................... 111

4.9 Flexural Frequency Sweep Test...................................................................................... 114

4.9.1 Test Results............................................................................................................. 114

4.9.2 Fitting with Gamma Distribution Function............................................................. 118

4.10 Varied-Strain Fatigue Test .......................................................................................... 121

4.10.1 The Strain Effect on Weibull Curves...................................................................... 121

4.10.2 A Hypothesis of Strain-Caused Fatigue Damage ................................................... 122

4.10.3 Test Results and Analysis ....................................................................................... 126

4.11 Varied-Temperature Fatigue Test ............................................................................... 135

4.11.1 The Temperature Effect on Weibull Curves........................................................... 135

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4.11.2 A Hypothesis of Temperature-Caused Fatigue Damage ........................................ 137

4.11.3 Test Results and Analysis ....................................................................................... 138

4.12 Findings and Discussions............................................................................................ 144

4.12.1 Findings in Fatigue Test Results and Regression Analysis .................................... 144