Reinforced Concrete Design with FRP Composites

by GangaRao; Hota V.S.

• ISBN13: 9780824758295
• ISBN10: 0824758293
• Edition: 1st
• Format: Hardcover
• Copyright: 2006-11-20
• Publisher: CRC Press

Summary

Although the use of composites has increased in many industrial, commercial, medical, and defense applications, there is a lack of technical literature that examines composites in conjunction with concrete construction. Fulfilling the need for a comprehensive, explicit guide, Reinforced Concrete Design with FRP Composites presents specific information necessary for designing concrete structures with fiber reinforced polymer (FRP) composites as a substitute for steel reinforcement and for using FRP fabrics to strengthen concrete members.In a reader-friendly, design-oriented manner, this book discusses the analysis, design, durability, and serviceability of concrete members reinforced with FRP. The authors first introduce the elements that constitute composites-the structural constituent and matrix-and discuss how composites are manufactured. Following an examination of the durability of FRP composites that contain fibers, such as glass, carbon, or aramid, the book illustrates how FRP external reinforcement systems (FRP-ER) can be used for enhancing the strength and stiffness of concrete structures using theory and design principles. The concluding chapter concentrates on serviceability aspects of concrete members internally reinforced with FRP.An excellent resource of design and construction practices, Reinforced Concrete Design with FRP Composites is a state-of-the-art reference on concrete members reinforced with FRP.

Table of Contents

Chapter 1 Frequently Asked Questions about Composite Materials	1
References and Selected Bibliography	18
Chapter 2 Properties of Constituent Materials: Concrete, Steel, Polymers, and Fibers	19
2.1 Introduction	19
2.2 Ingredients of Concrete	20
2.2.1 Aggregates	20
2.2.2 Cement	20
2.2.3 Admixtures	21
2.3 Types of Concrete	21
2.3.1 Classification Based on Unit Weight	22
2.3.2 Classification Based on Strength	22
2.4 Strength of Concrete	22
2.5 Strength Characteristics of Concrete	24
2.5.1 Stress—Strain Relationship	24
2.5.2 Modulus of Elasticity of Concrete	25
2.5.3 Flexural Strength of Concrete	27
2.5.4 Splitting Strength of Concrete	28
2.5.5 Poisson's Ratio	28
2.5.6 Shear Modulus of Concrete	29
2.6 Reinforcing Steel	29
2.6.1 Hot-Rolled Round Bars	29
2.7 Constituents of Fiber Reinforced Polymer (FRP) Composites	31
2.8 Polymers	33
2.8.1 General Characteristics	33
2.8.2 Thermoplastic Polymers	36
2.8.2.1 General	36
2.8.2.2 Common Thermoplastic Polymers	37
2.8.3 Thermoset Polymers	38
2.8.3.1 General	38
2.8.3.2 Commercially Available Thermoset Matrixes	38
2.8.4 Polyester Resins	38
2.8.5 Vinyl Ester Resins	40
2.8.6 Epoxies	41
2.8.7 Phenolics	43
2.8.8 Polyurethane Resins	44
2.8.9 Comparison of Thermoplastic and Thermoset Resins	44
2.8.10 Properties of Resins	45
2.9 Reinforcement (Fibers)	45
2.9.1 Glass Fibers	49
2.9.2 Carbon Fibers (Graphite Fibers)	50
2.9.2.1 General Description	50
2.9.2.2 Classification and Types	51
2.9.3 Manufacturing of Carbon Fibers	51
2.10 Aramid Fibers (Kevlar Fibers)	53
2.10.1 General Description	53
2.10.2 Characteristics	53
2.10.3 Commercial Applications of Aramid Fibers	54
2.11 Boron Fibers	54
2.12 Additives and Other Ingredients	54
2.13 Fillers	55
2.14 Fiber Surface Treatment (Sizing)	56
2.14.1 Glass Fibers	56
2.14.2 Carbon Fibers	56
2.14.3 Aramid Fibers	57
2.15 Properties of Fibers	57
References	58
Chapter 3 Manufacturing of Composite Components	63
3.1 Introduction	63
3.2 Manufacturing Methods	63
3.2.1 Hand (Wet) Lay-up/Automated Lay-up	64
3.2.2 Pultrusion	65
3.2.3 Filament Winding	68
3.2.4 Resin Transfer Molding (RTM)	69
3.2.5 Sheet Molding Compound (SMC)	70
3.2.6 Seemann Composite Resin Infusion Molding Process (SCRIMP)	71
3.2.7 Injection Molding	72
3.2.8 Compression Molding	73
3.2.9 Extrusion	74
3.3 Significance of QC and QA in Manufacturing	75
References	76
Chapter 4 Durability: Aging of Composites	79
4.1 Introduction	79
4.2 Environmental Factors Affecting FRP Properties	80
4.3 Durability and Safety Factors	81
4.4 Physical, Chemical, and Thermal Aging	83
4.5 Mechanisms of Polymer Degradation	84
4.6 Coupling Agent and Interface	84
4.7 Factors Affecting FRP Properties	85
4.7.1 Effect of Moisture	85
4.7.2 Effect of Alkaline/Acid/Salt Solutions	86
4.7.2.1 Alkaline Effects	86
4.7.2.2 Acid Effects	87
4.7.2.3 Salt Effects	87
4.7.3 Effect of Temperature	87
4.7.4 Effect of Stress	88
4.7.5 Creep/Relaxation	89
4.7.6 Creep Rupture	90
4.7.7 Fatigue	90
4.7.8 Ultraviolet (UV) Radiation	91
4.8 Accelerated Aging	91
4.8.1 Time–Temperature–Stress Superposition Principle	92
4.8.2 The Arrhenius Principle	92
4.8.3 Accelerated Aging Methodology	92
4.9 Manufacturing and Durability	96
4.10 Current Gaps in Durability Analysis	96
References	96
Chapter 5 Strengthening of Structural Members	103
5.1 Introduction	103
5.2 Bonding Concrete Beams with FRP-ER	104
5.3 Types of FRP Systems	105
5.4 Advantages and Limitations of FRP Composite Wraps for Reinforced Concrete Members	106
5.5 Fiber Wrap Technology Applications: Case Studies	107
5.5.1 Kattenbausch Bridge, Germany	108
5.5.2 Ibaach Bridge, Lucerne, Switzerland	108
5.5.3 City Hall of Gossau, St. Gall, Switzerland	108
5.5.4 Column Wrapping at Hotel Nikko, Beverly Hills, California, USA	108
5.5.5 Column Wrapping Projects by Caltrans for Seismic Resistance, USA	108
5.5.6 Column Wrapping for Corrosion Prevention, USA	109
5.5.7 Florida Department of Transportation, USA	109
5.5.8 Sins Wooden Bridge, Switzerland	109
5.5.9 South Temple Bridge, Interstate 15 (I-15), Utah, USA	109
5.5.10 East Street Viaduct, West Virginia, USA	110
5.5.11 Muddy Creek Bridge, West Virginia, USA	111
5.6 Compatibility of Steel-Reinforced Concrete and FRP-ER	118
5.7 The ACI Guide Specifications	118
5.7.1 Introduction	118
5.7.2 Shipping and Storage	119
5.7.3 Handling	119
5.7.4 Installation	120
5.7.5 Substrate Preparation	120
5.7.6 Surface Preparation	121
5.7.7 Application of Constituents	121
5.8 Design Properties of FRP-ER and Constituents	122
5.8.1 Design Properties of FRP-ER	122
5.8.2 Strength Reduction Factors	124
5.8.3 FRP Reinforcement for Flexural Strengthening	125
5.8.4 Effect of Bending Strength Increase on Shear Strength	126
5.8.5 Initial Member Strain Prior to Bonding	126
5.8.6 Nominal and Design Strength	126
5.8.7 Flexural Strengthening Limits	126
5.8.8 Failure Modes	127
5.8.9 Strain and Stress in FRP-ER	128
5.8.10 Ductility	129
5.8.11 Serviceability	130
5.8.12 Creep-Rupture and Fatigue Stress Limits	130
5.9 Failure Modes	131
5.10 Flexural Forces in FRP-ER Strengthened Beams	133
5.11 Flexural Strains and Stresses in FRP-ER Strengthened Beams	135
5.11.1 Depth of Neutral Axis (c = kd) with and without FRP-ER	138
5.11.2 Value of Neutral Axis Factor (k) with FRP-ER	139
5.11.3 Value of k without FRP-ER	141
5.11.4 Service Load Stresses (Post-Cracking) in Steel	141
5.11.5 Service Load Stresses in FRP-ER	142
5.12 Nominal Flexural Strength of a Singly Reinforced Beam	143
5.12.1 Tension-Controlled Failure with FRP-ER Rupture	143
5.12.2 Tension-Controlled Failure without FRP Rupture	145
5.12.3 Tension- and Compression-Controlled Failure with Steel Yielding and without FRP Rupture	147
5.12.4 Compression-Controlled Failure without Steel Yielding and without FRP Rupture	148
5.12.5 Balanced Failure	148
5.13 Trial-and-Error Procedure for Analysis and Design	150
5.14 Computation of Deflection and Crack Width	151
5.15 Design Examples on Flexure	151
5.15.1 Flexural Strengthening with FRP-ER (U.S. Standard Units)	151
5.15.2 Flexural Strengthening with FRP-ER (SI Units)	171
5.16 Shear Behavior of Wrapped Concrete Members	191
5.16.1 Wrapping Configurations for Shear Strengthening	191
5.16.2 Ultimate Strength	192
5.16.3 Effective Strain	193
5.16.4 Spacing	195
5.16.5 Total Shear Strength	195
5.17 Design Examples on Shear	195
5.17.1 Shear Strengthening with FRP-ER (U.S. Units)	195
5.17.2 Shear Strengthening with FRP-ER (SI Units)	201
Notation	208
References	210
Chapter 6 Design and Behavior of Internally FRP-Reinforced Beams	215
6.1 Introduction	215
6.2 Advantages and Limitations of Steel and FRP Reinforcements	216
6.3 Design Philosophy	217
6.3.1 Design Assumptions	218
6.3.2 Strength Limit States and Strength Reduction Factors	218
6.3.3 Material Properties for Design	219
6.3.3.1 Strength of Straight FRP Bars	219
6.3.3.2 Strength of FRP Bars at Bends	220
6.3.3.3 Shear	220
6.4 Flexural Behavior and Failure Modes of Rectangular FRP-Reinforced Beams	221
6.4.1 Concept of Tension and Compression Failure Modes	221
6.4.2 Balanced Failure: The Concept	221
6.4.2.1 (c/d) Ratio Approach for Balanced Strain Condition in Rectangular and Nonrectangular Concrete Beams	221
6.4.2.2 Balanced (Percentage) Reinforcement Ratio Approach for a Rectangular Concrete Beam	222
6.4.3 Tension Failure Mode	224
6.4.3.1 Linear Stress Distribution (ƒc less than ƒc')	224
6.4.3.2 Rectangular Stress Distribution (ƒc = ƒc')	225
6.4.4 Compression Failure Mode	226
6.4.5 Examples on Nominal Strength of FRP-Reinforced Beams	228
6.4.5.1 Examples in U.S. Standard Units	228
6.4.5.2 Examples in SI Units	236
6.5 Minimum and Maximum FRP Reinforcement Ratios	238
6.5.1 Minimum FRP Reinforcement	238
6.5.2 Maximum FRP Reinforcement	239
6.6 Temperature and Shrinkage Reinforcement	239
6.7 Energy Absorption in FRP-Reinforced Members: Ductility and Deformability Factors	240
6.7.1 Ductility Factor	240
6.7.2 Deformability Factor	242
6.7.3 Comparison of Deformability Factors	245
6.8 Shear Strength of FRP-Reinforced Beams	247
6.8.1 Shear Design Philosophy	247
6.8.2 Considerations for Using FRP Reinforcement in Shear	247
6.8.3 Limits on Tensile Strain of Shear Reinforcement	247
6.8.4 Shear Strength of FRP-Reinforced Members	248
6.8.4.1 Contribution of Concrete, Kcƒ	248
6.8.4.2 Shear Contribution of FRP Stirrups, Vƒ	249
6.8.5 Maximum Amount of Shear Reinforcement	251
6.8.6 Minimum Amount of Shear Reinforcement	251
6.8.7 Detailing of Shear Stirrups	251
Commentary	255
References	256
Chapter 7 Bond and Development Length	259
7.1 Introduction	259
7.2 Bond Behavior of Steel Bars	261
7.3 Bond Behavior of FRP Bars	263
7.4 Research on Bond Strength of FRP Bars	266
7.5 Estimation of Bond Strength	269
7.6 Current Research Findings	272
7.6.1 Bar Location Effect or Top-Bar Effect	273
7.6.2 Effect of Concrete Cover	273
7.6.3 Development Length of a Bent Bar	274
7.6.4 Tension Lap Splice	275
7.7 Examples	277
7.8 Summary	277
References	278
Chapter 8 Serviceability: Deflection and Crack Width	283
8.1 Introduction	283
8.2 Serviceability of Concrete Structures	283
8.3 Deflections	284
8.3.1 ACI 318 Provisions for Deflection Control	284
8.3.1.1 Minimum Thickness for Deflection Control (indirect Method)	285
8.3.1.2 Direct Method of Limiting Deflection Values	285
8.3.2 Calculation of Deflection (Direct Method)	288
8.4 Practical Considerations for the Control of Deflections	290
8.5 Examples on Deflections	290
8.5.1 Examples in U.S. Standard Units	290
8.5.2 Examples in SI Units	306
8.6 Crack Widths	319
8.6.1 ACI 318 Provisions for Crack Widths	319
8.7 Examples on Crack Widths	322
8.7.1 Examples in U.S. Standard Units	322
8.7.2 Examples in SI Units	334
8.8 Creep-Rupture	340
8.8.1 Concept of Creep	340
8.8.2 Concept of Creep-Rupture	340
8.9 Creep-Rupture Stress Limits	341
8.10 Examples of Creep-Rupture Stress Limits	342
8.10.1 Examples in U.S. Standard Units	342
8.10.2 Examples in SI Units	344
8.11 Fatigue Stress Limits	345
References	346
Glossary	349
Appendix A	363
Appendix B	369
Index	375