Structural Performance of Prestressed Self-Consolidating Concrete Bridge Girders Made with Limestone Aggregates Nadim Wehbe Professor Arden Sigl Professor Zachary Gutzmer Graduate Research Assistant Chad Stripling Graduate Research Assistant South Dakota State University October 2009 Disclaimer The contents of this report reflect the work of the authors, who are responsible for the facts and the accuracy of the information presented. This document is disseminated under the sponsorship of the Mountain-Plains Consortium in the interest of information exchange. The U.S. Government assumes no liability for the contents or use thereof. North Dakota State University does not discriminate on the basis of race, color, national origin, religion, sex, disability, age, Vietnam Era Veteran's status, sexual orientation, marital status, or public assistance status. Direct inquiries to the Vice President of Equity, Diversity, and Global Outreach, 205 Old Main, (701) 231-7708. TABLE OF CONTENTS 1. Introduction .......................................................................................................................................... 1 1.1 Problem Description ........................................................................................................................ 1 1.2 Objectives ........................................................................................................................................ 2 1.3 Scope ................................................................................................................................................ 3 1.3.1 Study of Concrete Mixtures ...................................................................................................... 3 1.3.2 Study of Full-Scale Bridge Girders ........................................................................................... 3 2. Literature Review ................................................................................................................................. 5 2.1 Introduction ...................................................................................................................................... 5 2.2 SCC Constituent Materials and Properties....................................................................................... 5 2.2.1 Constituent Materials ................................................................................................................ 5 2.2.2 Fresh Properties ......................................................................................................................... 6 2.2.3 Hardened Properties .................................................................................................................. 8 2.2.4 Shrinkage ................................................................................................................................... 9 2.3 SCC Provisions by Departments of Transportation ....................................................................... 10 2.3.2 Illinois DOT ............................................................................................................................ 11 2.3.3 Michigan DOT ........................................................................................................................ 11 2.3.4 South Dakota DOT .................................................................................................................. 11 2.4 Transfer Length of Prestressing Strands ........................................................................................ 11 2.4.1 Code Provisions for Transfer Length ...................................................................................... 11 2.4.2 Buckner ................................................................................................................................... 12 2.4.3 Russell and Burns .................................................................................................................... 13 2.4.4 Barnes, Grove, and Burns ........................................................................................................ 13 2.4.5 Girgis and Tuan ....................................................................................................................... 14 2.5 Prestress Losses ............................................................................................................................. 15 2.5.1 AASHTO Standard Specifications for Highway Bridges Methods ........................................ 15 2.5.1.1 Concrete Shrinkage, SH .............................................................................................. 16 2.5.1.2 Elastic Shortening, ES ................................................................................................. 16 2.5.1.3 Creep of Concrete, CR ............................................................................................... 16 c 2.5.1.4 Steel Relaxation, CR .................................................................................................. 16 s 2.5.2 AASHTO LRFD Approximate Method .................................................................................. 17 2.5.3 PCI Design Handbook Method ............................................................................................... 18 2.5.3.1 Elastic Shortening, ES ................................................................................................. 18 2.5.3.2 Creep of Concrete, CR ................................................................................................ 19 2.5.3.3 Shrinkage of Concrete, SH .......................................................................................... 19 2.5.3.4 Steel Relaxation, RE ................................................................................................... 19 2.5.4 PCI Committee on Prestress Losses Method ........................................................................... 21 2.5.4.1 Elastic Shortening, ES ................................................................................................. 21 2.5.4.2 Creep of Concrete, CR ................................................................................................ 21 2.5.4.3 Shrinkage of Concrete, SH .......................................................................................... 22 2.5.4.4 Steel Relaxation, RET ................................................................................................. 23 2.6 Camber ........................................................................................................................................... 23 2.7 Flexural Strength of Prestressed Concrete Girders ........................................................................ 24 2.7.1 ACI Code Provisions for Flexural Strength ............................................................................ 25 2.7.2 AASHTO-LRFD Provisions for Flexural Strength ................................................................. 26 2.8 Shear Strength of Prestressed Concrete Girders ............................................................................ 26 2.8.1 ACI Code Provisions ............................................................................................................... 26 2.8.2 AASHTO-LRFD Provisions for Shear Strength ..................................................................... 28 2.9 Previous Tests of Full-Scale Prestressed SCC Girders .................................................................. 30 2.9.1 Hamilton, Labonte, and Ansley ............................................................................................... 30 2.9.2 Naito, Parent, and Brunns ........................................................................................................ 31 3. Evaluation of SCC Mixtures with Limestone Aggregate ................................................................ 33 3.1 Aggregates Measured Properties ................................................................................................... 33 3.1.1 Sieve Analysis ......................................................................................................................... 33 3.1.2 Density, Specific Gravity, and Absorption .............................................................................. 35 3.1.3 Bulk Density ............................................................................................................................ 35 3.2 Laboratory Concrete Mixtures ....................................................................................................... 35 3.2.1 Mix Design .............................................................................................................................. 35 3.2.2 Mixing and Batching ............................................................................................................... 37 3.2.3 Curing Methods ....................................................................................................................... 37 3.3 Fresh Properties ............................................................................................................................. 39 3.3.1 Slump Flow ............................................................................................................................. 39 3.3.2 Visual Stability Index (VSI) and T ....................................................................................... 41 20 3.3.3 J-Ring Spread .......................................................................................................................... 42 3.3.4 L-Box ...................................................................................................................................... 44 3.3.5 Column Segregation ................................................................................................................ 45 3.3.6 Air Content .............................................................................................................................. 46 3.3.7 Mix Temperature ..................................................................................................................... 47 3.4 Hardened Properties ....................................................................................................................... 47 3.4.1 Compressive Strength .............................................................................................................. 47 3.4.2 Flexural Strength (Modulus of Rupture) ................................................................................. 51 3.4.3 Modulus of Elasticity .............................................................................................................. 55 3.4.4 Hardened Visual Stability Index (HVSI) ................................................................................ 59 3.5 Shrinkage ....................................................................................................................................... 60 4. Structural Performance of Prestressed SCC Girders ..................................................................... 65 4.1 Introduction .................................................................................................................................... 65 4.2 Design of Test Specimens .............................................................................................................. 65 4.3 Instrumentation ........................................................................................................................ 69 4.3.1 Strain Gages ............................................................................................................................ 69 4.3.2 Detachable Mechanical Points ................................................................................................ 71 4.3.3 Extensometers ......................................................................................................................... 72 4.4 Specimen Fabrication and Delivery ............................................................................................... 74 4.5 Test Set Up and Procedure ............................................................................................................. 77 4.5.1 Test Set Up .............................................................................................................................. 77 4.5.2 Test Procedure ......................................................................................................................... 77 4.6 Measured Material Properties ........................................................................................................ 80 4.6.1 Fresh Concrete Properties ....................................................................................................... 80 4.6.2 Concrete Compressive Strength .............................................................................................. 80 4.6.3 Prestressing Strands ................................................................................................................. 82 4.7 Transfer Length .............................................................................................................................. 82 4.7.1 Measured Transfer Length ...................................................................................................... 82 4.7.2 Comparison of Measured and Calculated Transfer Length ..................................................... 85 4.8 Prestress Losses ............................................................................................................................. 85 4.8.1 Measured Prestress Losses ...................................................................................................... 85 4.8.2 Theoretical Prestress Losses .................................................................................................... 89 4.8.2.1 AASHTO Standard Specifications for Highway Bridges (2002) ............................... 89 4.8.2.2 AASHTO LRFD Bridge Design Specifications (2007) .............................................. 90 4.8.2.3 PCI Design Handbook (2004) ..................................................................................... 90 4.8.2.4 PCI Committee on Prestress Losses (1975) ................................................................ 91 4.8.3 Comparison of Measured and Calculated Prestress Losses ..................................................... 92 4.9 Camber ........................................................................................................................................... 93 4.10 Load Testing Results .................................................................................................................. 95 4.10.1 Girder AL Experimental Results ...................................................................................... 95 4.10.1.1 Measured Load−Deflection ......................................................................................... 97 4.10.1.2 Measured Strand Strain ............................................................................................... 97 4.10.1.3 Measured Concrete Strain ......................................................................................... 100 4.10.1.4 Measured Top and Bottom Strains at Mid-Span ....................................................... 102 4.10.1.5 Measured Strain in the Shear Reinforcement ............................................................ 103 4.10.2 Girder BL Experimental Results ..................................................................................... 105 4.10.2.1 Measured Load−Deflection ....................................................................................... 107 4.10.2.2 Measured Strand Strain ............................................................................................. 107 4.10.2.3 Measured Concrete Strain ......................................................................................... 110 4.10.2.4 Measured Top and Bottom Strains at Mid-Span ....................................................... 112 4.10.2.5 Measured Strain in the Shear Reinforcement ............................................................ 113 4.10.3 Girder CL Experimental Results ..................................................................................... 115 4.10.3.1 Measured Load−Deflection ....................................................................................... 117 4.10.3.2 Measured Strand Strain ............................................................................................. 118 4.3.10.3 Measured Concrete Strain ......................................................................................... 121 4.3.10.4 Measured Top and Bottom Strains at Mid-Span ....................................................... 123 4.5.10.5 Measured Strain in the Shear Reinforcement ............................................................ 124 4.11 Analysis of Flexural Behavior and Strength ............................................................................. 125 4.11.1 Measured Load-Deflection Characteristics ..................................................................... 125 4.11.2 Effective Stiffness under Cyclic Loading ....................................................................... 126 4.11.3 Analytical Evaluation of Flexural Behavior ................................................................... 127 4.11.3.1 Load-Deflection Relationships.................................................................................. 128 4.11.3.2 Moment-Curvature Relationships ............................................................................. 130 4.11.3.3 Cracking Moment ..................................................................................................... 132 4.11.3.4 Flexural Strength ....................................................................................................... 133 4.11.3.5 Flexural Rigidity for Deflection Calculations ........................................................... 133 4.12 Analysis of Concrete Shear Strength ........................................................................................ 136 4.12.1 Experimental Evaluation of Concrete Shear Strength .................................................... 136 4.12.2 Comparison of Experimental and Analytical Concrete Shear Strength .......................... 139 5. Prestressed Quartzite-Aggregate SCC Girders ............................................................................. 141 5.1 Introduction .................................................................................................................................. 141 5.2 Specimen Description, Instrumentation, and Test Set Up ........................................................... 141 5.3 Experimental Results ................................................................................................................... 143 5.3.1 Measured Material Properties................................................................................................ 143 5.3.2 Transfer Length ..................................................................................................................... 144 5.3.3 Load Testing Results ............................................................................................................. 145 5.3.3.1 Girder A (Control Specimen) .................................................................................... 145 5.5.3.2 Girder C..................................................................................................................... 147 5.5.3.3 Girder B..................................................................................................................... 149 5.3.3.4 Performance Assessment of the Quartzite-Aggregate Girders.................................. 153 5.3.3.5 Comparative Evaluation of Quartzite- and Limestone-Aggregate Girders ............... 154 6. Evaluation of SCC for Prestressed Bridge Girders ....................................................................... 157 6.1 Constructability ............................................................................................................................ 157 6.2 Finished Product .......................................................................................................................... 157 6.3 Material and Structural Performance ........................................................................................... 157 6.4 Economic Evaluation ................................................................................................................... 158 6.5 Special Provisions ........................................................................................................................ 159 7. Summary, Conclusions, and Recommendations ............................................................................ 161 7.1 Summary ...................................................................................................................................... 161 7.2 Conclusions .................................................................................................................................. 162 7.3 Implementation and Recommendations ....................................................................................... 163 References ............................................................................................................................................... 165 Appendix A: Aggregate Testing Data ................................................................................................... 169 Appendix B: Admixture Literature ....................................................................................................... 179 Appendix C: Girder Details ................................................................................................................... 187 Appendix D: Girder Instrumentation Details ...................................................................................... 189 Appendix E: Crack Maps ....................................................................................................................... 195 Appendix F: Special Provisions ............................................................................................................. 209 LIST OF FIGURES Figure 1.1 Measurement Methods of Concrete Flowabilty ......................................................................... 1 Figure 2.1 Slump Flow Test ........................................................................................................................ 6 Figure 2.2 J-Ring Test ................................................................................................................................. 7 Figure 2.3 L-Box Test ................................................................................................................................. 7 Figure 2.4 Column Segregation Test .......................................................................................................... 8 Figure 3.1 ⅜″ Limestone Chip Coarse Aggregate .................................................................................... 33 Figure 3.2 Coarse Aggregate Grain Distribution ...................................................................................... 34 Figure 3.3 Fine Aggregate Grain Distribution .......................................................................................... 34 Figure 3.4 Heat (Accelerated) Curing Box ............................................................................................... 37 Figure 3.5 Heat Curing Step-Up and Soak ................................................................................................ 38 Figure 3.6 Measured Average Slump Spread versus W/C and Amount of Superplasticizer .................... 40 Figure 3.7 Measured Average Slump Spread versus Normalized Amount of Superplasticizer ............... 41 Figure 3.8 T versus Normalized Amount of Superplasticizer ................................................................ 42 20 Figure 3.9 Measured Blocking Potential ................................................................................................... 42 Figure 3.10 Blocking Potential versus Amount of Superplasticizer and W/C Ratio ................................ 43 Figure 3.11 Blocking Potential versus Normalized Amount of Superplasticizer ..................................... 44 Figure 3.12 Measured L-Box Ratios ......................................................................................................... 44 Figure 3.13 Measured L-Box Ratio versus Amount of Superplasticizer and W/C Ratio ......................... 45 Figure 3.14 Measured Column Segregation .............................................................................................. 46 Figure 3.15 Measured Air Content ............................................................................................................ 46 Figure 3.16 Amount of Air Entrainer versus Normalized Amount of Superplasticizer for Air Content = 7.6% ....................................................................................................................... 47 Figure 3.17 Compressive Strength versus Age of Concrete ..................................................................... 48 Figure 3.18 Measured and Theoretical Strength Gain for S33 ................................................................. 49 Figure 3.19 Measured and Theoretical Strength Gain for S35 ................................................................. 50 Figure 3.20 Measured and Theoretical Strength Gain for S37 ................................................................. 50 Figure 3.21 Measured and Theoretical Strength Gain for S33-A ............................................................. 51 Figure 3.22 Measured Flexural Strength versus Age of Concrete ............................................................ 52 Figure 3.23 Measured Flexural Strength at 18 Hours ............................................................................... 53 Figure 3.24 Measured Flexural Strength at 3 Days ................................................................................... 53 Figure 3.25 Measured Flexural Strength at 7 Days ................................................................................... 54 Figure 3.26 Measured Flexural Strength at 14 Days ................................................................................. 54 Figure 3.27 Measured Flexural Strength at 28 Days ................................................................................. 55 Figure 3.28 Measured Flexural Strength at All Ages ................................................................................ 55 Figure 3.29 Measured Modulus of Elasticity versus Age of Concrete ..................................................... 56 Figure 3.30 Measured and Theoretical Modulus of Elasticity for S33 ..................................................... 57 Figure 3.31 Measured and Theoretical Modulus of Elasticity for S35 ..................................................... 57 Figure 3.32 Measured and Theoretical Modulus of Elasticity for S37 ..................................................... 58 Figure 3.33 Measured and Theoretical Modulus of Elasticity for S33-A ................................................. 58 Figure 3.34 Modulus of Elasticity versus Age of Concrete ...................................................................... 59 Figure 3.35 Sawn Cylinder for HVSI Evaluation ..................................................................................... 59 Figure 3.36 Shrinkage Beam Mold ........................................................................................................... 60 Figure 3.37 Measured and Calculated Shrinkage Strain for S33 .............................................................. 61 Figure 3.38 Measured and Calculated Shrinkage Strain for S35 .............................................................. 62 Figure 3.39 Measured and Calculated Shrinkage Strain for S37 .............................................................. 62 Figure 3.40 Measured and Calculated Shrinkage Strain for CC33 ........................................................... 63 Figure 3.41 Measured Shrinkage Strain for All Mixes ............................................................................. 63 Figure 4.1 Schematic Cross Section of the Hypothetical Bridge .............................................................. 65 Figure 4.2 Girder Cross Section and Strand Layout ................................................................................. 66 Figure 4.3 Details of Transverse and non-prestressed Longitudinal Reinforcement ................................ 67 Figure 4.4 Cross Section of the Test Specimens ....................................................................................... 68 Figure 4.5 Coordinate System and Strand Numbering Method ................................................................ 69 Figure 4.6 Strand Strain Gage ................................................................................................................... 70 Figure 4.7 Transfer Length Strain Gages .................................................................................................. 70 Figure 4.8 Embedded Strain Gage ............................................................................................................ 71 Figure 4.9 Line of Demec Points .............................................................................................................. 72 Figure 4.10 Whittemore Gage, Brass Insert, Contact Seat, and Contact Point ......................................... 72 Figure 4.11 LVDT for Deflection Measurement at Mid-Span .................................................................. 73 Figure 4.12 Cable-Extension Transducer .................................................................................................. 73 Figure 4.13 Strain Measurement LVDTs .................................................................................................. 74 Figure 4.14 Fabrication of the Girder Specimens ..................................................................................... 75 Figure 4.15 Deck Formwork and Reinforcement...................................................................................... 76 Figure 4.16 Girder Delivery and Unloading ............................................................................................. 77 Figure 4.17 Schematic of Test Set Up ...................................................................................................... 78 Figure 4.18 Test Set Up of a Girder Specimen ......................................................................................... 78 Figure 4.19 Steel Seating Plate ................................................................................................................. 79 Figure 4.20 Crack Marking ....................................................................................................................... 79 Figure 4.21 Prestressing Strand Load versus Strain .................................................................................. 82 Figure 4.22 Measured Concrete Strain Along Potential Transfer Length ................................................. 83 Figure 4.23 Measured Transfer Length for Girder AL ............................................................................. 83 Figure 4.24 Measured Transfer Length for Girder BL .............................................................................. 84 Figure 4.25 Measured Transfer Length for Girder CL .............................................................................. 84 Figure 4.26 Measured Prestress Losses for Girder AL ............................................................................. 86 Figure 4.27 Measured Prestress Losses for Girder BL ............................................................................. 86 Figure 4.28 Measured Prestress Losses for Girder CL ............................................................................. 87 Figure 4.29 Average Measured Prestress Losses for Girder AL and Girder CL ...................................... 88 Figure 4.30 Comparison of Measured and Calculated Effective Prestress ............................................... 93 Figure 4.31 Comparison of Measured and Calculated Camber ................................................................ 94 Figure 4.32 Girder AL at Different Stages During the Test ...................................................................... 96 Figure 4.33 Measured Load-Deflection – Girder AL ............................................................................... 97 Figure 4.34 Measured Strand Strain at Mid-Span Resulting from External Load – Girder AL ............... 98 Figure 4.35 Measured Strand Strain at Mid-Span Resulting from All Loads – Girder AL ...................... 98 Figure 4.36 Measured Strand Strain at Quarter-Span Resulting from External Load – Girder AL .......... 99 Figure 4.37 Measured Strand Strain at Quarter-Span Resulting from All Loads – Girder AL ............... 100 Figure 4.38 Measured Concrete Strain at Mid-Span Resulting from External Load – Girder AL ......... 100 Figure 4.39 Measured Concrete Strain at Mid-Span Resulting from All Loads – Girder AL ................ 101 Figure 4.40 Measured Concrete Strain at Quarter-Span Resulting from External Load – Girder AL .... 101 Figure 4.41 Measured Concrete Strain at Quarter-Span Resulting from All Loads – Girder AL ........... 102 Figure 4.42 Measured Compressive Strain along Top Horizontal LVDT at Mid-Span – Girder AL ..... 102 Figure 4.43 Measured Tensile Strain along Bottom Horizontal LVDT at Mid-Span – Girder AL ........ 103 Figure 4.44 Measured Strain Along Stirrup @ 22.5″ – Girder AL ......................................................... 103 Figure 4.45 Measured Strain Along Stirrup @ 52.5″ – Girder AL ......................................................... 104 Figure 4.46 Measured Strain Along Stirrup @ 82.5″ – Girder AL ......................................................... 104 Figure 4.47 Measured Strain Along Stirrup @ 112.5″ – Girder AL ....................................................... 105 Figure 4.48 Girder BL at Different Stages During the Test .................................................................... 106 Figure 4.49 Measured Load-Deflection – Girder BL .............................................................................. 107 Figure 4.50 Measured Strand Strain at Mid-Span Resulting from External Load – Girder BL.............. 108 Figure 4.51 Measured Strand Strain at Mid-Span Resulting from All Loads – Girder BL .................... 108 Figure 4.52 Measured Strand Strain at Quarter-Span Resulting from External Load – Girder BL ........ 109 Figure 4.53 Measured Strand Strain at Quarter-Span Resulting from All Loads – Girder BL ............... 110 Figure 4.54 Measured Concrete Strain at Mid-Span Resulting from External Load – Girder BL .......... 111 Figure 4.55 Measured Concrete Strain at Mid-Span Resulting from All Loads – Girder BL ................ 111 Figure 4.56 Measured Concrete Strain at Quarter-Span Resulting from External Load – Girder BL .... 112 Figure 4.57 Measured Concrete Strain at Quarter-Span Resulting from All Loads – Girder BL ........... 112 Figure 4.58 Measured Compressive Strain Along Bottom Horizontal LVDT at Mid-Span – Girder BL ..................................................................................................................... 113 Figure 4.59 Measured Strain Along Stirrup @ 22.5″ – Girder BL ......................................................... 113 Figure 4.60 Measured Strain Along Stirrup @ 52.5″ – Girder BL ......................................................... 114 Figure 4.61 Measured Strain Along Stirrup @ 82.5″ – Girder BL ......................................................... 114 Figure 4.62 Measured Strain Along Stirrup @ 112.5″ – Girder BL ....................................................... 115 Figure 4.63 Girder CL at Different Stages During the Test .................................................................... 116 Figure 4.64 Measured Cyclic Load-Deflection – Girder CL .................................................................. 117 Figure 4.65 Measured Load-Deflection Envelope – Girder CL .............................................................. 117 Figure 4.66 Measured Strand Strain at Mid-Span Resulting from External Load – Girder CL.............. 118 Figure 4.67 Measured Strand Strain at Mid-Span Resulting from All Loads – Girder CL .................... 119 Figure 4.68 Measured Strand Strain at Quarter-Span Resulting from External Load – Girder CL ........ 120 Figure 4.69 Measured Strand Strain at Quarter-Span Resulting from All Loads – Girder CL ............... 120 Figure 4.70 Measured Concrete Strain at Mid-Span Resulting from External Load – Girder CL .......... 121 Figure 4.71 Measured Concrete Strain at Mid-Span Resulting from All Loads – Girder CL ................ 121 Figure 4.72 Measured Concrete Strain at Quarter-Span Resulting from External Load – Girder CL .... 122 Figure 4.73 Measured Concrete Strain at Quarter-Span Resulting from All Loads – Girder CL ........... 122 Figure 4.74 Measured Compressive Strain Along Top Horizontal LVDT at Mid-Span – Girder CL .... 123 Figure 4.75 Measured Tensile Strain Along Bottom Horizontal LVDT at Mid-Span – Girder CL ....... 123 Figure 4.76 Measured Strain Along Stirrup @ 22.5″ – Girder CL ......................................................... 124 Figure 4.77 Measured Strain Along Stirrup @ 52.5″ – Girder CL ......................................................... 124 Figure 4.78 Measured Strain Along Stirrup @ 82.5″ – Girder CL ......................................................... 125 Figure 4.79 Measured Strain Along Stirrup @ 112.5″ – Girder CL ....................................................... 125 Figure 4.80 Comparison of Measured Load-Deflection Relationships ................................................... 126 Figure 4.81 Analytical and Experimental Load-Deflection – Girder AL ............................................... 128 Figure 4.82 Analytical and Experimental Load-Deflection – Girder BL ................................................ 129 Figure 4.83 Analytical and Experimental Load-Deflection – Girder CL ................................................ 129 Figure 4.84 Analytical and Experimental Moment-Curvature – Girder AL ........................................... 131 Figure 4.85 Analytical and Experimental Moment-Curvature – Girder BL ........................................... 131 Figure 4.86 Analytical and Experimental Moment-Curvature – Girder CL ........................................... 132 Figure 4.87 Analytical and Experimental Flexural Rigidity – Girder AL .............................................. 135 Figure 4.88 Analytical and Experimental Flexural Rigidity – Girder BL............................................... 135 Figure 4.89 Analytical and Experimental Flexural Rigidity – Girder CL............................................... 136 Figure 4.90 Inclination Angle of a Shear Crack...................................................................................... 137 Figure 5.1 Cross Section of the Quartzite-Aggregate Girder .................................................................. 142 Figure 5.2 Measured Transfer Length for Girder A ................................................................................ 144 Figure 5.3 Measured Transfer Length for Girder B ................................................................................ 145 Figure 5.4 Girder A at Different Stages During the Test ........................................................................ 146 Figure 5.5 Measured Load-Deflection – Girder A .................................................................................. 147 Figure 5.6 Girder C at Different Stages During the Test ........................................................................ 148 Figure 5.7 Measured Load-Deflection – Girder C .................................................................................. 148 Figure 5.8 Measured Stiffness Under Fatigue Loading – Girder C ........................................................ 150 Figure 5.9 Girder Stiffness Degradation – Girder C ............................................................................... 151 Figure 5.10 Girder B at Different Stages During the Monotonic Load Test ........................................... 152 Figure 5.11 Measured Load-Deflection – Girder B ................................................................................ 153 Figure 5.12 Measured Load-Deflection – Quartzite-Aggregate Girders ................................................ 154 Figure 5.13 Measured Load-Deflection – Quartzite-Aggregate and Limestone-Aggregate Girders ...... 155