For practicing engineers, students, contractors, building officials, plan checkers, and researchers. Drawing upon the author’s thiry-two years of experience, topics are covered in-depth and taken to the point of practical application.
For practicing engineers, students, contractors, building officials, plan checkers, and researchers.
Drawing upon the author’s thiry-two years of experience, topics are covered in-depth and taken to the point of practical application.
• Covers Concepts and Procedures of Practical and Modern Post-Tensioning Design
• Unbonded and Bonded (Grouted) Systems Construction Technology and Design Procedures
• Post-Tensioned Floor Design Step-by-Step Calculation
• Post-Tensioned Beam Design Step-by-Step Calculation
• Software and Design Tools; Design Flow Charts and Examples
• Stress Losses; Deflections; Cracking and Crack Width
• Application of Finite Elements to Design
• Covers US and European Codes for Post-Tensioning Design
• Application of Building Information Modeling (BIM) to Post-Tensioning
• Provides detailed know-how for expedient and efficient designs
• Emphasis is on practical designs for “safe” and “serviceable” buildings
• Meets the needs of a wide audience designers; plan checkers; contractors; students; academics
• Discusses comparative features and advantages of bonded and unbonded systems
The book builds on over three decades of author’s observation and design of post-tensioning projects in more than 35 countries worldwide. Having met and discussed with thousands of others whose work encompasses the design or construction of post-tensioned projects, the author presents his observations and experience in a clear and concise format, highlighting the concepts and procedures that lead to good practice and economical designs.
TABLE CONTENTS
1. INTRODUCTION
1.1 Purpose and Outline
1.2 Brief History of Post-Tensioning in Building Construction
1.3 References
2. POST-TENSIONING
2.1 Brief Description of Prestressing
2.1.1 Prestressing Options
2.2 Distinguishing Features and Advantages of Post-Tensioning Construction
2.3 Application of Post-Tensioning in Building Construction
2.3.1 Floor Systems Flat Slab Construction
2.3.2 Floor Systems Beam and Slab Construction
2.3.3 Podium Slab in Low-Rise Buildings
2.3.4 Transfer Plates
2.3.5 Mat/Raft Foundation
2.3.6 Industrial Ground-Supported Slabs
2.3.7 Slab-On-Grade SOG; Residential and Light Industrial
2.3.8 Retrofit through External Post-Tensioning
2.3.9 Post-Tensioning to Restore Geometry in Seismic Frame
2.3.10 Post-Tensioning in Walls
2.3.11 Post-Tensioning in Columns
2.3.12 Special Application of Post-Tensioning
2.4 Post-Tensioning Material and Hardware
2.4.1 Prestressing Steel
2.4.2 Tendons
2.4.3 Stressing Equipment
2.4.4 Grouting Equipment
2.5 Post-Tensioning Construction
2.5.1 Construction with Unbonded Tendons
2.5.2 Construction with Grouted Tendons
2.5.3 Marking and Recording of Tendon Positions
2.6 Economics and Material Quantities
2.6.1 Material Quantities
2.6.2 Construction Cost
2.7 Repair; Retrofit; Maintenance and Life Cycle
2.7.1 Floors Reinforced with Grouted Tendons
2.7.2 Floor Reinforced with Unbonded Tendons
2.8 References
3. DESIGN OF CONCRETE FLOORS
3.1 General Requirements
3.2 Requirements of Design Procedure
3.3 Concrete Design in Relation to other Materials
3.4 Design Characteristics of Post-Tensioning
3.5 Analysis and Design Process
3.5.1 Analysis and Design Steps
3.5.2 Structural Modeling
3.6 References
4. DESIGN CONCEPTS AND PROCEDURES
4.1 Principal Objectives
4.1.1 Safety Ultimate Limit State (ULS)
4.1.2 Functionality Service Limit State (SLS)
4.1.3 Economy
4.1.4 Legality
4.2 Material
4.2.1 Concrete
4.2.2 Prestressing Steel
4.2.3 Non-prestressed Steel
4.3 Sizing
4.3.1 Support Spacing
4.3.2 Slab Thickness
4.3.3 Beam Dimensions
4.3.4 Common Sizing Examples
4.4 Durability
4.4.1 Exposure to Corrosive Elements
4.4.2 Fire Protection
4.4.3 Wear
4.5 Load Path
4.5.1 Prerequisites of a Load Path
4.5.2 Strip Method
4.5.3 Slab as a Continuum
4.5.4 One Way and Two Way Systems
4.6 Structural System
4.6.1 Slab Systems
4.6.2 Slab Bands
4.6.3 Column Drops Capitals/Drop Panels
4.6.4 Waffle Slabs
4.6.5 Joist Slabs
4.6.6 Beams
4.6.7 Support Conditions; Releases and Stiffness Assignments
4.6.8 Other Floor System Examples
4.7 Loading
4.7.1 Selfweight
4.7.2 Superimposed Dead Load
4.7.3 Live Load
4.7.4 Prestressing
4.7.5 Wind/Earthquake/Special Loads
4.8 Prestressing
4.8.1 Load Balancing
4.8.2 Force Selection
4.8.3 Effective Flange Width of T-Beams
4.8.4 Judicial Placing of Tendons
4.8.5 Average Minimum Precompression
4.8.6 Hyperstatic Actions (Secondary Actions)
4.8.7 Constant Force and Variable Force Designs
4.8.8 Tendon Layout
4.8.9 Post-Tensioning System Selection and Performance;
4.8.10 Bonded/Unbonded
4.9 Analysis Options
4.9.1 Underlying Assumptions
4.9.2 Analysis Models
4.9.3 Simple Frame Method (SFM)
4.9.4 Equivalent Frame Method (EFM)
4.9.5 Finite Element Method (FEM)
4.10 Serviceability Check; Serviceability Limit State (SLS)
4.10.1 Load Combinations
4.10.2 ACI 318 Crack Control; Stress Check; Non-prestressed Rebar
4.10.3 EC2 Crack Control; Stress Check; Non-prestressed Rebar
4.10.4 TR43 Crack Control; Stress Check; Non-prestressed Rebar
4.10.5 Significance of Allowable Stresses; Code Compliance
4.10.6 Deflection Control
4.10.7 Vibration Control
4.11 Safety Check Ultimate Limit State (ULS)
4.11.1 Load Combinations for Gravity Design
4.11.2 Hyperstatic Actions
4.11.3 Redistribution of Moments
4.11.4 Design for Strength
4.11.5 Safety Against Cracking Moment
4.11.6 Punching Shear
4.11.7 One-Way Shear
5. 10-STEPS FO R DESIGN OF A POST-TENSIONED FLOO R
6. POST-TENSIONED FLOO R DESIGN; Step by Step Calculation
6.1 Geometry and Structural System
6.2 Material Properties
6.3 Loads
6.4 Design Parameters
6.5 Actions Due to Dead and Live Loads
6.6 Post-Tensioning
6.7 Code Check for Serviceability
6.8 Code Check for Strength
6.9 Code Check for Initial Condition
6.10 Detailing
6.11 References
7. POST-TENSIONED BEAM DESIGN; Step by Step Calculation
7.1 Geometry and Structural System
7.2 Material Properties
7.3 Loads
7.4 Design Parameters
7.5 Actions Due to Dead and Live Loads
7.6 Post-Tensioning
7.7 Code Check for Serviceability
7.8 Code Check for Strength
7.9 Code Check for Initial Condition
7.10 Detailing
7.11 References
8. COMPUTER APPLICAT ION TO DESIGN OF RC OR PT BUILDINGS
8.1 Overview
8.2 BIM; Building Information Modeling and Structural Design Process
8.3 Integration of Structural Analysis in BIM
8.4 Approximation in Analysis
8.5 Computer-Based Design Example
8.6 References
9. POST-TENSIONING IN MULT I-STO RY BUILDINGS
9.1 Structural Impacts of Post-Tensioning in Multi-Story Buildings
9.2 Effects of Post-Tensioning on Column and Wall Supports
9.3 Precompression from Post-Tensioning and Restraint of Supports
9.3.1 Temperature Effects
9.3.2 Precompression from Prestressing
9.4 References
10. STRESS LO SSES IN PRESTRESSING STEEL
10.1 Overview
10.2 Distribution of Stress
10.3 Friction and Seating Loss Calculations
10.3.1 Stress Loss due to Friction
10.3.2 Elongation
10.3.3 Stress Loss due to Seating of Strand
10.4 Long-Term Stress Loss Estimate
10.4.1 Elastic Deformation of Concrete
10.4.2 Creep of Concrete
10.4.3 Shrinkage of Concrete
10.4.4 Relaxation of Prestressing Steel
10.5 Examples
10.5.1 Friction and Long-Term Stress Losses of an Unbonded Post-Tensioned Slab
10.5.2 Friction and Long-Term Stress Losses of a Beam Reinforced with Grouted Tendons
10.6 Notations
10.7 References
11. STRUCTURAL MODELING OF POST-TENSIONED TENDONS
11.1 Structural Modeling Requirements of Prestressing Tendons
11.2 Structural Modeling Options of Prestressing Tendons
11.2.1 Modeling of Tendon as Applied Loading
11.2.2 Modeling of Tendon as a Load Resisting Element
11.2.3 Tendon Modeling Features and Comparison
11.2.4 Example
11.3 References
12. SECTION DESIGN FO R BENDING
12.1 Bending Design Overview
12.2 Design Based on Strain Compatibility
12.3 Bending Design Based on Simplified Code Formulas
12.3.1 ACI 318 Simplified Bending Design
12.3.2 EC2 Simplified Bending Design
13. NOTATIONS
14. DATA TABLES
4.12 Initial Condition; Transfer of Prestressing
4.13 References