ACI 435R 95 1995
$62.02
435R-95: Control of Deflection in Concrete Structures (Reapproved 2000)
| Published By | Publication Date | Number of Pages |
| ACI | 1995 | 89 |
This report presents a consolidated treatment of initial and time-dependent deflection of reinforced and prestressed concrete elements such as simple and continuous beams and one-way and two-way slab systems. It presents the state of the art in practice on deflection as well as analytical methods for computer use in deflection evaluation. The introductory chapter and four main chapters are relatively independent in content. Topics include “Deflection of Reinforced Concrete One-way Flexural Members,” “Deflection of Two-way Slab Systems,” and “Reducing Deflection of Concrete Members.” One or two detailed computational examples for evaluating the deflection of beams and two-way action slabs and plates are given at the end of Chapters 2, 3, and 4. These computations are in accordance with the current ACI- or PCI-accepted methods of design for deflection. Keywords: beams; camber; code; concrete; compressive strength; cracking; creep; curvature; deflection; high-strength concrete; loss of prestress; modulus of rupture; moments of inertia; plates; prestressing; pretensioned; post-tensioned; reducing deflection; reinforcement; serviceability;shrinkage; slabs; strains; stresses; tendons; tensile strength; time-dependent deflection.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 1 | CONTENTS CONTENTS |
| 2 | CHAPTER 1— INTRODUCTION CHAPTER 1— INTRODUCTION |
| 3 | CHAPTER 2— DEFLECTION OF REINFORCED CONCRETE ONE- WAY FLEXURAL MEMBERS CHAPTER 2— DEFLECTION OF REINFORCED CONCRETE ONE- WAY FLEXURAL MEMBERS 2.1—Notation 2.1—Notation |
| 4 | 2.2- General 2.2- General 2.2.1 Introduction 2.2.1 Introduction 2.2.2 Objectives 2.2.2 Objectives 2.2.3 Significance of defection observation 2.2.3 Significance of defection observation 2.3- Material properties 2.3- Material properties |
| 5 | 2.3.1 Concrete modulus of rupture 2.3.1 Concrete modulus of rupture 2.3.2 Concrete modulus of elasticity 2.3.2 Concrete modulus of elasticity |
| 6 | 2.3.3 Steel reinforcement modulus of elasticity 2.3.3 Steel reinforcement modulus of elasticity 2.3.4 Concrete creep and shrinkage 2.3.4 Concrete creep and shrinkage |
| 9 | 2.4-Control of deflection 2.4-Control of deflection 2.4.1 Tension steel reinforcement ratio limitations 2.4.1 Tension steel reinforcement ratio limitations 2.4.2 Minimum thickness limitations 2.4.2 Minimum thickness limitations 2.4.3 Computed deflection limitations 2.4.3 Computed deflection limitations 2.5-Short-term deflection 2.5-Short-term deflection 2.5.1 Untracked members 2.5.1 Untracked members |
| 10 | 2.5.2 Cracked members-Effective moment of inertia Ie 2.5.2 Cracked members-Effective moment of inertia Ie |
| 11 | 2.5.2.1 Simply supported beams 2.5.2.1 Simply supported beams 2.5.2.2 Continuous beams 2.5.2.2 Continuous beams 2.5.2.3 Approximate Ie estimation 2.5.2.3 Approximate Ie estimation |
| 13 | 2.5.3 Incremental moment-curvature method 2.5.3 Incremental moment-curvature method |
| 14 | 2.6-Long-term deflection 2.6-Long-term deflection 2.6.1 ACI method 2.6.1 ACI method 2.6.2 ACI Committee 435 modified method (Branson, 1963, 1977) 2.6.2 ACI Committee 435 modified method (Branson, 1963, 1977) 2.6.3 Other methods 2.6.3 Other methods 2.6.3.1 CEB-FIP Model Code simplified method 2.6.3.1 CEB-FIP Model Code simplified method |
| 15 | 2.6.3.2 Section curvature method (Ghali, Favre, andElbadry 2002) 2.6.3.2 Section curvature method (Ghali, Favre, andElbadry 2002) 2.6.4 Finite element method 2.6.4 Finite element method 2.7—Temperature-induced deflections 2.7—Temperature-induced deflections |
| 16 | 2.7.1 Temperature gradient on unrestrained crosssection 2.7.1 Temperature gradient on unrestrained crosssection 2.7.2 Effect of restraint on thermal movement 2.7.2 Effect of restraint on thermal movement APPENDIX A2 APPENDIX A2 Example A2.1: Deflection of a four-span beam Example A2.1: Deflection of a four-span beam |
| 20 | Example A2.2: Temperature-induced deflections Example A2.2: Temperature-induced deflections CHAPTER 3- DEFLECTION OF PRESTRESSEDCONCRETE ONE-WAY FLEXURAL MEMBERS CHAPTER 3- DEFLECTION OF PRESTRESSEDCONCRETE ONE-WAY FLEXURAL MEMBERS 3.1-Notation 3.1-Notation |
| 21 | 3.2- General 3.2- General 3.2.1 Introduction 3.2.1 Introduction 3.2.2 Objectives 3.2.2 Objectives |
| 22 | 3.2.3 Scope 3.2.3 Scope 3.3- Prestressing reinforcement 3.3- Prestressing reinforcement 3.3.1 Types of reinforcement 3.3.1 Types of reinforcement 3.3.1.1 Stress-relieved wires and strands 3.3.1.1 Stress-relieved wires and strands 3.3.1.2 High-tensile-strength prestressing bars 3.3.1.2 High-tensile-strength prestressing bars 3.3.2 Modulus of elasticity 3.3.2 Modulus of elasticity 3.3.3 Steel relaxation 3.3.3 Steel relaxation |
| 24 | 3.4-Loss of prestress 3.4-Loss of prestress 3.4.1 Elastic shortening loss 3.4.1 Elastic shortening loss 3.4.2 Loss of prestress due to creep of concrete 3.4.2 Loss of prestress due to creep of concrete |
| 27 | 3.4.4 Friction losses in post-tensioned beams 3.4.4 Friction losses in post-tensioned beams |
| 28 | 3.5-General approach to deformation considerations -Curvature and deflections 3.5-General approach to deformation considerations -Curvature and deflections 3.5.1 Beams subjected to prestressing only 3.5.1 Beams subjected to prestressing only |
| 31 | 3.5.2 Beams subjected to prestressing and external loads 3.5.2 Beams subjected to prestressing and external loads |
| 32 | 3.5.3 Moment-curvature relationship 3.5.3 Moment-curvature relationship |
| 33 | 3.6-Short-term deflection and camber evaluation inprestressed beams 3.6-Short-term deflection and camber evaluation inprestressed beams 3.6.1 Uncracked members 3.6.1 Uncracked members 3.6.2 Cracked members 3.6.2 Cracked members |
| 35 | 3.6.3 Bilinear computation method 3.6.3 Bilinear computation method |
| 36 | 3.6.4 Incremental moment-curvature method 3.6.4 Incremental moment-curvature method |
| 38 | 3.7-Long-term deflection and camber evaluation in prestressedbeams 3.7-Long-term deflection and camber evaluation in prestressedbeams |
| 39 | 3.7.1 PCI multipliers method 3.7.1 PCI multipliers method 3.7.2 Incremental time-steps method 3.7.2 Incremental time-steps method |
| 40 | 3.7.3 Approximate time-steps method 3.7.3 Approximate time-steps method |
| 41 | 3.7.4 Axial strain and curvature method (Ghali-Favre) 3.7.4 Axial strain and curvature method (Ghali-Favre) 3.7.5 Prestress loss method 3.7.5 Prestress loss method 3.7.6 CEB-FIP model code method 3.7.6 CEB-FIP model code method |
| 42 | APPENDIX A3 APPENDIX A3 Example A3.1 Example A3.1 |
| 47 | Example A3.2 Example A3.2 |
| 50 | CHAPTER 4- DEFLECTION OF TWO-WAY SLAB SYSTEMS CHAPTER 4- DEFLECTION OF TWO-WAY SLAB SYSTEMS 4.1-Notation 4.1-Notation |
| 51 | 4.2-Introduction 4.2-Introduction 4.3-Deflection calculation methods for two-way slabsystems 4.3-Deflection calculation methods for two-way slabsystems 4.3.1 Immediate deflection of uncracked slabs 4.3.1 Immediate deflection of uncracked slabs 4.3.1.1 Classical solutions 4.3.1.1 Classical solutions 4.3.1.2 Crossing beam methods 4.3.1.2 Crossing beam methods |
| 53 | 4.3.1.3 Finite element method 4.3.1.3 Finite element method 4.3.2 Effect of cracking 4.3.2 Effect of cracking 4.3.3 Restraint cracking 4.3.3 Restraint cracking |
| 54 | 4.3.4 Long-term deflections 4.3.4 Long-term deflections 4.3.4.1 Detailed calculations 4.3.4.1 Detailed calculations |
| 55 | 4.3.4.2 ACI multiplier 4.3.4.2 ACI multiplier 4.4-Minimum thickness requirements 4.4-Minimum thickness requirements |
| 57 | 4.5-Prestressed two-way slab systems 4.5-Prestressed two-way slab systems 4.5.1 Introduction 4.5.1 Introduction 4.5.2 Basic principle for deflection control 4.5.2 Basic principle for deflection control 4.5.3 Minimum stab thickness for deflection control 4.5.3 Minimum stab thickness for deflection control 4.5.4 Methods for defection calculations 4.5.4 Methods for defection calculations |
| 58 | 4.6-Loads for deflection calculations 4.6-Loads for deflection calculations |
| 61 | 4.7-Variability of deflections 4.7-Variability of deflections 4.8-Allowable deflections 4.8-Allowable deflections |
| 62 | APPENDIX A4 APPENDIX A4 Example A4.1- Deflection design example for long-termdeflection of a two-way slab Example A4.1- Deflection design example for long-termdeflection of a two-way slab |
| 65 | Example A4.2- Deflection calculation for a flat plateusing the crossing beam method Example A4.2- Deflection calculation for a flat plateusing the crossing beam method |
| 66 | CHAPTER 5- REDUCING DEFLECTIONOF CONCRETE MEMBERS CHAPTER 5- REDUCING DEFLECTIONOF CONCRETE MEMBERS 5.1-Introduction 5.1-Introduction |
| 67 | 5.2-Design techniques 5.2-Design techniques 5.2.1 Increasing section depth 5.2.1 Increasing section depth |
| 68 | 5.2.2 Increasing section width 5.2.2 Increasing section width 5.2.3 Addition of compression reinforcement 5.2.3 Addition of compression reinforcement 5.2.4 Addition of tension reinforcement 5.2.4 Addition of tension reinforcement 5.2.5 Prestressing application 5.2.5 Prestressing application 5.2.6 Revision of structure geometry 5.2.6 Revision of structure geometry 5.2.7 Revision of deflection Limit criteria 5.2.7 Revision of deflection Limit criteria |
| 69 | 5.3-Construction techniques 5.3-Construction techniques 5.3.1 Concrete curing to allow gain in strength 5.3.1 Concrete curing to allow gain in strength 5.3.2 Concrete curing to reduce shrinkage and creep 5.3.2 Concrete curing to reduce shrinkage and creep 5.3.3 Control of shoring and reshoring procedures 5.3.3 Control of shoring and reshoring procedures 5.3.4 Delay of the first loading 5.3.4 Delay of the first loading 5.3.5 Delay in installation of deflection-sensitive elements or equipment 5.3.5 Delay in installation of deflection-sensitive elements or equipment 5.3.6 Location of deflection-sensitive equipment to avoid deflection problems 5.3.6 Location of deflection-sensitive equipment to avoid deflection problems 5.3.7 Provision of architectural details to accommodate expected deflection 5.3.7 Provision of architectural details to accommodate expected deflection 5.3.8 Building camber into floor slabs 5.3.8 Building camber into floor slabs |
| 70 | 5.3.9 Ensuring that top bars are not displaced downward 5.3.9 Ensuring that top bars are not displaced downward 5.4-Materials selection 5.4-Materials selection 5.4.1 Selection of materials for mix design that reduceshrinkage and creep or increase the moduli of elasticity andrupture 5.4.1 Selection of materials for mix design that reduceshrinkage and creep or increase the moduli of elasticity andrupture 5.4.2 Use of concretes with a higher modulus of elasticity 5.4.2 Use of concretes with a higher modulus of elasticity 5.4.3 Use of concretes with a higher modulus of rupture 5.4.3 Use of concretes with a higher modulus of rupture 5.4.4 Addition of short discrete fibers to the concrete mix 5.4.4 Addition of short discrete fibers to the concrete mix 5.5-Summary 5.5-Summary REFERENCES REFERENCES Chapter 2 Chapter 2 |
| 73 | Chapter 3 Chapter 3 |
| 74 | Chapter 4 Chapter 4 |
| 76 | Chapter 5 Chapter 5 |
| 77 | APPENDIX B— DETAILS OF THE SECTION CURVATURE METHOD FOR CALCULATING DEFLECTIONS* APPENDIX B— DETAILS OF THE SECTION CURVATURE METHOD FOR CALCULATING DEFLECTIONS* B1—Introduction B1—Introduction B1.1 Notation B1.1 Notation |
| 78 | B2—Background B2—Background B3—Cross-sectional analysis outline B3—Cross-sectional analysis outline B4—Material properties B4—Material properties B4.1 Creep B4.1 Creep |
| 79 | B4.2 Shrinkage B4.2 Shrinkage B4.3 Relaxation of prestressing steel B4.3 Relaxation of prestressing steel B5—Sectional analysis B5—Sectional analysis B5.1 Review of basic equations B5.1 Review of basic equations |
| 80 | B5.2 Instantaneous and time-dependent stress and strain B5.2 Instantaneous and time-dependent stress and strain |
| 82 | B5.3 Commentary on the general procedure and on a special case (nonprestressed sections subjected to M without N) B5.3 Commentary on the general procedure and on a special case (nonprestressed sections subjected to M without N) |
| 83 | B6—Calculation when cracking occurs B6—Calculation when cracking occurs B7—Tension-stiffening B7—Tension-stiffening |
| 84 | B7.1 Branson’s effective moment of inertia B7.1 Branson’s effective moment of inertia B7.2 CEB-FIP approach B7.2 CEB-FIP approach B7.3 Other tension stiffening approaches B7.3 Other tension stiffening approaches B8—Deflection and change in length of a frame member B8—Deflection and change in length of a frame member |
| 85 | B9-Summary and conclusions B9-Summary and conclusions B10—Examples B10—Examples |
| 87 | B11—References B11—References B11.1 Referenced standards and reports B11.1 Referenced standards and reports |
| 88 | B11.2 Cited references B11.2 Cited references |
| 89 | CONVERSION FACTORS—INCH-POUND TO SI (METRIC) CONVERSION FACTORS—INCH-POUND TO SI (METRIC) |
