# Post Tensioning

Post Tensioning Design & Analysis Programs Theory Manual (143 Pages)

Chapter 1 – Description
1.1 Analysis Method
1.2 Units
1.3 Sign Convention
Chapter 2 – Prestressed Concrete Freebody Diagrams
2.1 The Concrete-Only Freebody Diagram
2.2 The Concrete/Tendon Freebody Diagram
2.3 The Easy Way to Calculate Secondary Moments
3.4 Concentrated Moment
3.5 Wind Moment
Chapter 4 – Cross-Section Types
4.1 Section Identification
4.2 Development of Flexural Reinforcing (WARNING)
Chapter 5 – Tendon Profiles
5.1 Types 1 and 8 (Centerline Parabola)
5.2 Types 2 and 9 (Face-to-Face Parabola)
5.3 Types 3 and 12 (Compound Parabola)
5.4 Types 4 and 10 (Single-Point Centerline Harp)
5.5 Types 5 and 11 (Single-Point Face-to-Face Harp)
5.6 Type 6 (Double-Point Centerline Harp)
5.7 Type 7 (Double-Point Face-to-Face Harp)
6.1 Equivalent Loads in the Constant Prestress Force Method
(a) Curvature Loads for Each Tendon Type
(b) CGC and CGS Discontinuities
(c) Tendon Force Discontinuities
6.2 Equivalent Loads in the Variable Prestress Force Method
Chapter 7 – Flexural and Torsional Stiffnesses
7.1 Flexural Stiffness for Columns (Rigid or Equivalent Frame)
(a) Modeling of Top and Bottom Columns
7.2 Flexural Stiffness of Rigid Frame Beams
7.3 Equivalent Frame Geometry and Definitions
7.4 Flexural Stiffness of Equivalent Frame Beams
7.5 Stiffness of Equivalent Frame Torsional Members
(a) The “Standard” Torsional Member
(b) The Transverse Beam Torsional Member
(c) An Adjustment in Kt for “Parallel” Beams
7.6 The “Equivalent” Column Stiffness Kec
Chapter 8 – Frame Moments, Shears, and Design Points
8.1 User-Controlled Design Points
8.2 Program-Controlled Design Points
8.3 Moments
8.4 Shears
Chapter 9 – Design by PTData+
9.1 General Design Theory for Post-Tensioned Concrete
(a) Flexural Strength
(b) Cracking Moment
(c) Arbitrary Minimums
1. One-Way Beams and Slabs
2. Two-Way Slabs
(d) Shear Strength
9.2 The Computer-Generated “Automatic” Design
(a) Special Conditions at Cantilevers
9.3 Iteration to the Final Design
Chapter 10 – Flexural Stresses
10.1 Concrete Flexural Stresses at Service Loads
10.2 Concrete Flexural Stresses at Transfer of Prestress
Chapter 11 – Flexural Strength
11.1 Strength Theory in Prestressed Concrete
11.2 The Precise Stress-Strain Method
11.3 The Simplified ACI Code Method
11.4 Strength Calculations in PTData+
(a) The Basic Cross-Section Geometry
(b) The Reinforcing Index
(c) How PTData+ Calculates As and A’s
1. Sections Requiring Tension Steel Only
2. Sections Requiring Tension and Compression Steel
(d) Ultimate Tendon Stress fps
1. Unbonded Tendons
2. Bonded Tendons
Chapter 12 – Inelastic Moment Redistribution
12.1 Inelastic Theory in Continuous Beams
12.2 Code Redistribution of Ultimate Moments (1.4DL+1.7LL)
(a) How the Redistribution is Done
12.3 Redistribution of DL+LL/4 Moments
Chapter 13 – Deflection
Chapter 14 – Shear Strength
14.1 Beam Shear
(a) Concrete Shear Strength
1. Vcn (ACI Equation 11-10)
2. Vcw (ACI Equation 11-13)
3. Vci (ACI Equation 11-11)
(b) Reinforcement Shear Strength
(c) Minimums
(d) Maximum Stirrup Spacing
14.2 Punching Shear
(a) Shears and Moments
(b) Applied and Allowable Stresses on the Critical Punching Shear
Section
(c) Critical Punching Shear Section Dimensions
(d) Critical Punching Shear Section Properties
(e) Column and Slab Edge Relationships
(f ) The “d ” Dimension in Punching Shear Calculations
PTDATA+
Theory Manual
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