1 General Provisions
1.0.1 This specification is formulated with a view to implementing the national technical and economic policies, achieving safety and usability, advanced technology and economic rationality and ensuring quality in the design, construction and acceptance of unbounded prestressed concrete structures.
1.0.2 This specification is applicable to the design, construction and acceptance of the unbounded prestressed concrete structure adopted in building engineering.
1.0.3 For the unbounded prestressed concrete structure, the rational design and construction scheme shall be determined according to the functional requirements, material supply and construction conditions of buildings.
1.0.4 In addition to this specification, the design, construction and acceptance of unbounded prestressed concrete structure shall also comply with those specified in the current relevant standards of the nation.
2 Terminologies and Symbols
2.1 Terminologies
2.1.1 Unbonded prestressed bar
Single prestressed steel strand or single prestressed fiber reinforced polymer bar which is wrapped with special anti-corrosive lubricant coating and plastic sheath, and can maintain relative sliding with the concrete under prestress when it is arranged in the section of a concrete member.
2.1.2 Unbounded prestressed concrete structure
The concrete structure for which unbonded prestressed bundles are set inside or outside the concrete structure member and prestress is set up by tensioning.
2.1.3 External prestressed bundle
The unbonded prestressed bar which is distributed outside the section of concrete structure member and is connected with the member only in the anchorage zone and at the position of deviator, is referred to as external bundle.
2.1.4 External prestressing
The prestress produced by the post-tensioned prestressed bar which is distributed outside the section of concrete member.
2.1.5 Deviator
The middle supporting block which changes the direction of external prestressed bundle and is connected with the concrete member.
2.1.6 Fiber reinforced polymer bar
The rod-shaped fiber reinforced polymer product produced with continuous fiber bundle according to pultrusion process, which is referred to as fiber reinforced bar, and may be classified into carbon fiber reinforced bar and aramid fiber reinforced bar, etc. according to different reinforcing materials.
2.2 Symbols
1 General Provisions
2 Terminologies and Symbols
2.1 Terminologies
2.2 Symbols
3 Basic Requirements
3.1 General Requirements
3.2 Protection Against Fire and Corrosion
4 Materials and Anchorage System
4.1 Concrete and Ordinary Steel Bar
4.2 Prestressed Bar
4.3 Anchor
5 Calculations and Details for Design
5.1 General Rules
5.2 One-way System
5.3 Two-way System
5.4 Beam with External Bonded Bar
5.5 Unbonded Prestressed Fiber-reinforced Flexural Concrete Member
5.6 Unbonded Prestressed Super-long Concrete Structure
6 Construction and Acceptance
6.1 Manufacture, Package and Transportation of Unbonded Prestressed Bar
6.2 Placing of Unbonded Prestressed Bar and Concrete Pouring
6.3 Tensioning, Releasing and Anchor Sealing for Unbonded Prestressed Bar
6.4 Construction of External Prestressing
6.5 Openings and Demolishing of Unbonded Prestressed Slabs
6.6 Project Acceptance
Appendix A Estimation of Unbonded Prestressed Bars
Appendix B Prestress Loss of Curved Unbonded Prestressed Bar Due to Anchor Deformation and Shrinkage of Unbounded Bar
Appendix C Stiffness/Equivalent Frame Calculation Model of Equivalent Column
Appendix D Tensioning Record Sheets of Unbonded Prestressed Bars
Explanation of Wording in This Specification
List of Quoted Standards
