Contents
Preface…………………………………………………………………………….xvii
Author……………………………………………………………………………..xxi
Chapter 1 Cement-Based Composites—A Case for Sustainable Construction……….1
Introduction…………………………………………………………………..1
Cement and Concrete Production……………………………….2
Current Trends………………………………………………………….2
Structure of This Book……………………………………………………………………………………..4
Textile Reinforced and High-Volume Content Cement Composites……………………5
Development of Design Methodologies for Fiber Reinforced Composites…………..5
Sustainability—The Main Driver for New Materials and Design Methods
Is the Economy of Construction System…………………………………………………………6
References………………………………………………………………………………………………………6
Chapter 2 Historical Aspects of Conventional Fiber Reinforced Concrete Systems…………………9
Introduction…………………………………………………………………………………………………….9
Prehistoric Developments………………………………………………………………………………….9
Asbestos Cement…………………………………………………………………………………………… 10
Hatscheck Process…………………………………………………………………………………………. 12
Ferrocement………………………………………………………………………………………………….. 13
Cement Composites in Modular and Panelized Construction Systems…………………. 13
Glass Fiber Reinforced Concrete…………………………………………………………………….. 14
Cellulose Fibers…………………………………………………………………………………………….. 17
Continuous Fiber Systems………………………………………………………………………………. 18
Thin Section Composites Using Textiles………………………………………………………….. 19
References……………………………………………………………………………………………………. 19
Chapter 3 Ductile Cement Composite Systems…………………………………………………………………23
Introduction…………………………………………………………………………………………………..23
Mechanics of Toughening……………………………………………………………………………….24
Macro-Defect-Free Cements……………………………………………………………………………25
Ductile Composites with High-Volume Fiber Contents……………………………………….26
Extrusion………………………………………………………………………………………………………27
Compression Molding…………………………………………………………………………………….28
Spin Casting………………………………………………………………………………………………….28
Mixing High-Volume Fraction Composites……………………………………………………….29
Composites Using Continuous Fibers and Textiles……………………………………………..30
Mesh Reinforced Cementitious Sheets………………………………………………………….30
Pultrusion…………………………………………………………………………………………………30
Matrix Phase Modifications……………………………………………………………………………. 33
Rapid Setting……………………………………………………………………………………………. 33
Fly Ash……………………………………………………………………………………………………. 33
Calcium Hydroxide Reduction…………………………………………………………………………34
Rheology……………………………………………………………………………………………………… 35
Hybrid Short Fiber Reinforcement…………………………………………………………………… 35
Hybrid Reinforcement: Woven Mesh and Discrete Fibers……………………………………36
Conclusions…………………………………………………………………………………………………..36
References…………………………………………………………………………………………………….36
Chapter 4 Textile Reinforcement in Composite Materials………………………………………………….. 41
Introduction………………………………………………………………………………………………….. 41
Terminology and Classifications Systems…………………………………………………………. 42
Fiber and Fabric Terminology………………………………………………………………… 42
Composites………………………………………………………………………………………….. 42
AR Glass Fibers…………………………………………………………………………………………….44
Kevlar………………………………………………………………………………………………………….. 45
Carbon Filaments and Yarns…………………………………………………………………………… 45
Textile Reinforced Composites………………………………………………………………………..46
Textile Fibers……………………………………………………………………………………………. 47
Textile Forms……………………………………………………………………………………………. 47
Monofilaments (25–200 μm, Continuous)…………………………………………………….. 47
Whiskers (<1 μm, Discontinuous)………………………………………………………………..48
Textile Terminology…………………………………………………………………………………..48
Scrims…………………………………………………………………………………………………………..49
Stitch-Bonded Fabrics…………………………………………………………………………………….50
Leno Weave Technique………………………………………………………………………………….. 51
Analysis of Woven Textile Composites…………………………………………………………….. 51
Composite Moduli in Textile Reinforcements…………………………………………………… 53
Modeling of Textile Composites at the Representative Volume Level…………………..54
Mechanical Strength and Damage Accumulation……………………………………………….56
References……………………………………………………………………………………………………. 57
Chapter 5 Single Yarns in Woven Textiles: Characterization of Geometry
and Length Effects………………………………………………………………………………………… 61
Introduction………………………………………………………………………………………………….. 61
Kevlar Fabric………………………………………………………………………………………………… 61
Single Yarn Tensile Tests………………………………………………………………………………..69
Weibull Analysis…………………………………………………………………………………………… 71
References……………………………………………………………………………………………………. 74
Chapter 6 Introduction to Mechanics of Composite Materials……………………………………………. 75
Introduction………………………………………………………………………………………………….. 75
Volume Fraction……………………………………………………………………………………………. 75
Composite Density………………………………………………………………………………………… 76
Nature of Load Sharing and Load Transfer………………………………………………………. 76
Computation of Transverse Stiffness……………………………………………………………….. 78
Strength of a Lamina………………………………………………………………………………………82
Case Study 1: Matrix Fails First, σmu Governs……………………………………………………83
Case Study 2: Four Stages of Cracking……………………………………………………………..85
Laminated Composites……………………………………………………………………………………88
Stiffness of an Off-Axis Ply…………………………………………………………………………….88
Ply Discount Method………………………………………………………………………………………96
Failure Criteria………………………………………………………………………………………………96
Maximum Stress Theory…………………………………………………………………………….97
Interactive Failure Criterion, Tsai–Hill…………………………………………………….97
References…………………………………………………………………………………………………….97
Chapter 7 Mechanical Testing and Characteristic Responses……………………………………………..99
Introduction…………………………………………………………………………………………………..99
Concepts of Closed-Loop Testing…………………………………………………………………….99
Components and Parameters of CLC……………………………………………………………… 101
The Proportional-Integral-Derivative (PID) Controller………………………………… 101
Actuators and Servomechanism…………………………………………………………………….. 102
Hydraulic Actuators and Servovalves………………………………………………………… 102
Servohydraulic Testing Machines………………………………………………………………….. 103
The Electronics……………………………………………………………………………………….. 103
Compression Test………………………………………………………………………………………… 104
Uniaxial Tension Test…………………………………………………………………………………… 107
Flexure Test………………………………………………………………………………………………… 108
Fracture Tests……………………………………………………………………………………………… 110
Cyclic Test………………………………………………………………………………………………….. 110
Compliance-Based Approach………………………………………………………………………… 111
Mechanical Performance—Test Methods for Measurement of
Toughness of FRC……………………………………………………………………………………….. 113
Round Panel Tests……………………………………………………………………………………….. 114
Fatigue Tests……………………………………………………………………………………………….. 116
Impact Resistance………………………………………………………………………………………… 118
Restrained Shrinkage…………………………………………………………………………………… 119
Aging and Weathering………………………………………………………………………………….120
References…………………………………………………………………………………………………..120
Chapter 8 Fiber Pullout and Interfacial Characterization…………………………………………………. 123
Introduction………………………………………………………………………………………………… 123
Significance of Interfacial Modeling………………………………………………………………. 123
Analytical Derivation for Fiber Pullout Fiber and Textile Composites……………….. 125
Pullout Response in Elastic Stage (Stage 1)………………………………………………… 127
Pullout Response in the Nonlinear Stage (Stage 2)………………………………………. 129
Pullout Response in Dynamic Stage (Stage 3)…………………………………………….. 130
Algorithm for Pullout Simulation………………………………………………………………….. 130
Single-Fiber Pullout Experiments………………………………………………………………….. 131
Textile Pullout Tests…………………………………………………………………………………….. 132
Energy Dissipation during Pullout…………………………………………………………………. 138
Finite Element Simulation…………………………………………………………………………….. 139
Fracture-Based Approach…………………………………………………………………………….. 140
Strain Energy Release Rate…………………………………………………………………………… 140
Modeling of the Transverse Yarn Anchorage Mechanism…………………………………. 143
Finite Difference Approach for the Anchorage Model……………………………………… 145
Characterization of Interfacial Aging…………………………………………………………….. 147
Theoretical Modeling of Interfacial Aging……………………………………………………… 148
Conclusions………………………………………………………………………………………………… 148
References………………………………………………………………………………………………….. 148
Chapter 9 Fracture Process in Quasi-Brittle Materials…………………………………………………….. 151
Introduction………………………………………………………………………………………………… 151
Linear Elastic Fracture Mechanics………………………………………………………………… 152
Stress Intensity Factor and Fracture Toughness……………………………………………….. 153
Fracture Process Zone………………………………………………………………………………….. 154
Equivalent Elastic Cracks……………………………………………………………………………… 155
Cohesive Crack Models………………………………………………………………………………… 157
Closing Pressure Formulations……………………………………………………………………… 158
R-Curve Approach………………………………………………………………………………………. 159
Derivation of R-Curves………………………………………………………………………………… 160
Alternative Forms of R-Curves……………………………………………………………………… 162
Stress–Crack Width Relationship………………………………………………………………….. 162
Stress Intensity Approach Using Fiber Pullout or Stress–Crack Width…………… 165
Termination of Stable Crack Growth Range……………………………………………………. 167
Toughening under Steady-State Condition………………………………………………………. 168
Discrete Fiber Approach Using Fiber Pullout for Toughening…………………………… 168
Comparison with Experimental Results…………………………………………………………. 172
Simulation of Glass Fiber Concrete……………………………………………………………….. 175
Compliance-Based Approach………………………………………………………………………… 177
References………………………………………………………………………………………………….. 179
Chapter 10 Tensile Response of Continuous and Cross-Ply Composites……………………………… 183
Introduction………………………………………………………………………………………………… 183
Specimen Preparation………………………………………………………………………………….. 183
(0/90) Composite Laminates…………………………………………………………………………. 187
(+45) Composite Laminates………………………………………………………………………….. 188
Compression Response…………………………………………………………………………………. 188
PP Fiber Laminates……………………………………………………………………………………… 189
Flexural Response……………………………………………………………………………………….. 190
Microstructural Damage and Toughness………………………………………………………… 192
References………………………………………………………………………………………………….. 193
Chapter 11 Inelastic Analysis of Cement Composites Using Laminate Theory……………………. 195
Introduction………………………………………………………………………………………………… 195
Stiffness of a Lamina…………………………………………………………………………………… 195
Stiffness of a Ply along Material Direction……………………………………………………… 196
Ply Discount Method……………………………………………………………………………………. 199
Damage-Based Modeling Using a Nonlinear-Incremental Approach………………….200
Failure Criteria for Lamina……………………………………………………………………………203
Generalized Load Displacement for the Composite Response……………………………203
Performance of Model: Simulation of Tensile Load………………………………………….204
Simulation of Flexural Results……………………………………………………………………….208
References………………………………………………………………………………………………….. 210
Chapter 12 Tensile and Flexural Properties of Hybrid Cement Composites ………………………… 211
Introduction………………………………………………………………………………………………… 211
Manufacturing Techniques and Materials………………………………………………………. 212
Experimental Program…………………………………………………………………………………. 212
Specimen Preparation………………………………………………………………………………….. 213
Flexural Three-Point Bending Tests…………………………………………………………… 213
Direct Tension Tests………………………………………………………………………………… 213
Brittle Fibers…………………………………………………………………………………………… 213
Ductile Fibers…………………………………………………………………………………………. 215
Hybrid Composites………………………………………………………………………………….. 215
Tension Results……………………………………………………………………………………….. 216
Comparison of Injection Molding and Compression Molding……………………….. 218
Fracture Resistance Curves……………………………………………………………………….220
Conclusion…………………………………………………………………………………………………..223
References…………………………………………………………………………………………………..223
Chapter 13 Correlation of Distributed Damage with Stiffness Degradation Mechanisms………225
Introduction…………………………………………………………………………………………………225
Role of Microcracking Cement Composites in Tension……………………………………..225
Tensile Response of Textile Reinforced Cement Composites……………………………..225
Crack Spacing Measurement………………………………………………………………………….228
Imaging Procedures for Measurement of Crack Spacing…………………………………..228
Effect of Fabric Type……………………………………………………………………………………. 231
Effect of Mineral Admixtures……………………………………………………………………….. 233
Effect of Accelerated Aging………………………………………………………………………….. 235
Rheology and Microstructure……………………………………………………………………….. 235
Effect of Curing…………………………………………………………………………………………..236
Effects of Pressure……………………………………………………………………………………….. 237
Microcrack–Textile Interaction Mechanisms……………………………………………………238
Conclusions…………………………………………………………………………………………………240
References…………………………………………………………………………………………………..240
Chapter 14 Flexural Model for Strain-Softening and Strain-Hardening Composites……………..243
Introduction ………………………………………………………………………………………………..243
Correlation of Tensile and Flexural Strength from Weibull Statistics Perspective…… 244
Derivation of Closed-Form Solutions for Moment–Curvature Diagram………………245
Stage 1: (0 < β < 1) and (λ < ω)………………………………………………………………….249
Stage 2: 1 < β < α…………………………………………………………………………………….250
Stage 3: β > α…………………………………………………………………………………………. 252
Stage 3.1: β > α and λ < ω……………………………………………………………………. 252
Stage 3.2: β > α and ω < λ < λcu…………………………………………………………….. 253
Simplified Expressions for Moment–Curvature Relations…………………………………. 255
Case 2.1: 1 < β < ρ and 0 < λ < ω……………………………………………………………… 255
Case 3.1: α < β < βtu and 0 < λ < ω…………………………………………………………….. 257
Crack Localization Rules………………………………………………………………………………260
Algorithm to Predict Load–Deflection Response of the
Four-Point Bending Test……………………………………………………………………………….. 261
Parametric Study of Material Parameters………………………………………………………..262
Prediction of Load–Deformation Response……………………………………………………..263
Steel FRC………………………………………………………………………………………………..264
Engineered Cementitious Composites (ECC)………………………………………………265
AR Glass and PE Textile Reinforced Cement Composites……………………………. 267
Closed-Form Moment–Curvature Solutions for FRC Beams with
Reinforcement…………………………………………………………………………………………269
Parametric Studies…………………………………………………………………………………… 272
Conclusions………………………………………………………………………………………………… 275
Nomenclature……………………………………………………………………………………………… 276
Subscripts……………………………………………………………………………………………….277
References…………………………………………………………………………………………………..277
Chapter 15 Back-Calculation Procedures of Material Properties from Flexural Tests…………… 279
Introduction ……………………………………………………………………………………………….. 279
Case A: Tension Data Are Unavailable……………………………………………………….280
Case A1: Inverse Analysis of Load–Deflection Response of
Polymeric Fibers………………………………………………………………………………….280
Case A2: Inverse Analysis Load–Deflection Response of
Macro-PP-FRC (English System)…………………………………………………………..283
Data Reduction by the ARS Method and RILEM Test Method………………………….284
Case B: Tension Data Are Available, Forward and Back Calculation……………..286
Case B1: Glass FRC……………………………………………………………………………..286
Case B2: Simulation of Steel FRC………………………………………………………….287
AR Glass Fiber Concrete………………………………………………………………………………290
Comparison with the RILEM Approach…………………………………………………………. 291
Conclusion…………………………………………………………………………………………………..292
References…………………………………………………………………………………………………..293
Chapter 16 Modeling of Fiber Reinforced Materials Using Finite Element Method………………295
Introduction…………………………………………………………………………………………………295
Model Concrete Structure with ABAQUS……………………………………………………….297
Implicit or Explicit Analysis Types…………………………………………………………….297
Element…………………………………………………………………………………………………..297
Quasi-Static Simulation…………………………………………………………………………….298
Concrete Model in ABAQUS…………………………………………………………………….299
Calculation of Moment–Curvature Response………………………………………………300
Nodal Calculation………………………………………………………………………………..300
Element Calculation……………………………………………………………………………..300
Implementation of the User Material Model………………………………………………..302
Inverse Analysis of FRC……………………………………………………………………………….302
Finite Element Simulation of Round Panel Test……………………………………………….303
Simulation Result…………………………………………………………………………………….303
Moment–Curvature Relationship for Rigid Crack Model………………………………….305
Modeling of Round Panel Test with Rigid Crack Model……………………………………307
Elastic Range (Mα < Mcr)…………………………………………………………………………..307
Plastic Range (Mα > Mcr)…………………………………………………………………………..308
Prediction of Load–Deflection Response……………………………………………………. 311
Summary……………………………………………………………………………………………………. 312
References………………………………………………………………………………………………….. 313
Chapter 17 Flexural Design of Strain-Softening Fiber Reinforced Concrete……………………….. 315
Introduction ……………………………………………………………………………………………….. 315
Strain-Softening FRC Model……………………………………………………………………. 316
Moment–Curvature Response……………………………………………………………………….. 317
Bilinear Moment–Curvature Diagram……………………………………………………………. 319
Allowable Tensile Strain……………………………………………………………………………….320
Ultimate Moment Capacity………………………………………………………………………. 322
Minimum Postcrack Tensile Capacity for Flexure……………………………………….. 322
Hybrid Reinforcement Conversion Design Chart…………………………………………. 323
Deflection Calculation for Serviceability…………………………………………………………324
Minimum Postcrack Tensile Strength for Shrinkage and Temperature……………….. 325
Design Examples…………………………………………………………………………………………. 326
Design Example 1: Slab on Grade……………………………………………………………… 326
Equivalent Moment Capacity with SFRC, fc′ = 4000 psi (27.6 MPa)………….. 326
Equivalent Tensile Capacity…………………………………………………………………. 327
Design Example 2: Equivalent Reinforced Slab with Various Steel Yield
Strengths………………………………………………………………………………………………… 327
Step 1: Calculate Existing Moment Capacity Based on 1-Ft. Strip…………….. 327
Step 2: Calculate Normalized Ultimate Moment…………………………………….. 328
Step 3: Determine Postcrack Tensile Strength Using Simplified Equation….. 328
Design Example 3: Simply Supported Slab with Serviceability Criteria…………. 329
Ultimate Moment Capacity………………………………………………………………….. 329
Check Tensile Strain Limit…………………………………………………………………… 330
Short-Term Deflection………………………………………………………………………….. 330
Stress Distributions……………………………………………………………………………… 331
Design Example 4: Four-Span Floor Slab…………………………………………………… 332
Moment Capacity………………………………………………………………………………… 332
Shear Capacity……………………………………………………………………………………. 333
Design Example 5: Retaining Wall……………………………………………………………. 333
Design Example 6: Design with Macropolymeric Fibers……………………………… 335
Problem Formulation…………………………………………………………………………… 335
Proposed Approach…………………………………………………………………………….. 335
Moment Capacity of a 7-In.-Thick Reinforced Concrete Slab…………………… 335
Replace the Moment Capacity with Macropolymeric Fiber, fc′ = 4000 psi….. 335
Replace Tensile Capacity……………………………………………………………………… 335
Moment Capacity of an 8-In.-Thick Reinforced Concrete Slab…………………. 336
Replace the Moment Capacity with Macrofibers, fc′ = 4000 psi………………… 336
Replace Tensile Capacity……………………………………………………………………… 336
Conclusions………………………………………………………………………………………………… 337
References …………………………………………………………………………………………………. 337
Chapter 18 Fiber Reinforced Aerated Concrete……………………………………………………………….. 339
Introduction………………………………………………………………………………………………… 339
AFRC Production………………………………………………………………………………………… 342
Density and Compressive Strength Relationship……………………………………………… 342
Flexural Response………………………………………………………………………………………..344
Pore Structure………………………………………………………………………………………………346
References…………………………………………………………………………………………………..348
Chapter 19 Sisal Fiber Reinforced Composites…………………………………………………………………349
Introduction…………………………………………………………………………………………………349
Sisal Fiber Composites…………………………………………………………………………………. 351
Stress–Strain Behavior and Cracking Mechanisms………………………………………….. 351
Flexural Response…………………………………………………………………………………… 353
Fatigue……………………………………………………………………………………………………….. 355
Fiber Matrix Pullout Behavior………………………………………………………………………. 359
Tension Stiffening Model………………………………………………………………………….364
References………………………………………………………………………………………………….. 367
Chapter 20 Restrained Shrinkage Cracking……………………………………………………………………..369
Introduction…………………………………………………………………………………………………369
Review of Drying Shrinkage Testing Methods…………………………………………………369
Plastic Shrinkage Cracking………………………………………………………………………. 370
Restrained Shrinkage Cracking………………………………………………………………… 370
Restrained Drying Shrinkage Test Methodology…………………………………………. 371
Modeling Restrained Shrinkage Cracking………………………………………………….. 373
Lattice Models……………………………………………………………………………………. 375
Lamina Model……………………………………………………………………………………. 376
Moisture Diffusion and Free Shrinkage……………………………………………………… 376
Effect of Creep in Restrained Shrinkage Cracking………………………………………….. 378
Age-Dependent Concrete Strength………………………………………………………………… 378
Equilibrium and Compatibility Conditions………………………………………………………380
Stress–Strain Development……………………………………………………………………………380
Parametric Study…………………………………………………………………………………….. 383
Comparison of Experimental Data and Simulations…………………………………….. 383
Conclusions…………………………………………………………………………………………………384
References…………………………………………………………………………………………………..384
Chapter 21 Flexural Impact Test……………………………………………………………………………………..387
Introduction…………………………………………………………………………………………………387
Experimental Program………………………………………………………………………………….388
Material Properties and Mix Design…………………………………………………………..388
AR Glass Composite…………………………………………………………………………….388
Sisal Fiber Composites…………………………………………………………………………388
Drop Weight Impact Setup…………………………………………………………………… 389
Dynamic Calibration……………………………………………………………………………390
Results and Discussions…………………………………………………………………………….394
AR Glass Composite…………………………………………………………………………….394
Effect of Drop Height…………………………………………………………………………………… 395
Effect of Number of Lamina and Specimen Orientation…………………………..397
Energy Absorption……………………………………………………………………………….397
Sisal Fiber Composites…………………………………………………………………………….. 398
Discussions………………………………………………………………………………………………….403
References…………………………………………………………………………………………………..403
Chapter 22 Textile Composites for Repair and Retrofit………………………………………………………407
Introduction…………………………………………………………………………………………………407
Comparison of FRP Systems with Textile Reinforced Concrete…………………………408
Experimental Program………………………………………………………………………………….408
Materials Tests…………………………………………………………………………………………….409
Structural Tests…………………………………………………………………………………………….409
Tensile Properties……………………………………………………………………………………. 411
Structural Tests of Masonry Walls…………………………………………………………………. 413
Conclusions………………………………………………………………………………………………… 415
References………………………………………………………………………………………………….. 416
Chapter 23 Retrofit of Reinforced Concrete Beam–Column Joints Using Textile Cement
Composites…………………………………………………………………………………………………. 417
Introduction ……………………………………………………………………………………………….. 417
Experimental Program…………………………………………………………………………………. 418
Material Properties………………………………………………………………………………….. 418
Experimental Results……………………………………………………………………………………420
Behavior of the Specimens………………………………………………………………………..420
Absorbed Energy……………………………………………………………………………………..420
Total Energy………………………………………………………………………………………. 421
Dissipated Energy……………………………………………………………………………….. 422
Recovery Energy………………………………………………………………………………… 423
Stiffness Degradation……………………………………………………………………………….424
Conclusions………………………………………………………………………………………………… 425
References………………………………………………………………………………………………….. 425
Chapter 24 Dynamic Tensile Characteristics of Textile Cement Composites….. 427
Introduction………………………………………………………………………………………………… 427
Dynamic Tensile Testing………………………………………………………………………………. 427
Dynamic Testing of Cement Composites………………………………………………………… 428
Experimental Methodology…………………………………………………………………………… 428
Fabric–Cement Composites………………………………………………………………….. 428
Dynamic Loading Devices and Technique…………………………………………………. 429
Data Processing Method for Dynamic Tensile Testing…………………………………. 429
Dynamic Characterization……………………………………………………………………. 429
Results and Discussions……………………………………………………………………………….. 429
Unidirectional Sisal Fiber Reinforced Composite………………………………………… 429
Fabric Reinforced Composites………………………………………………………………….. 431
Cracking and Failure Behavior……………………………………………………………… 433
Microstructural Features……………………………………………………………………… 436
Conclusions………………………………………………………………………………….. 437
References…………………………………………………………………………………… 438