1, the calculation index of steel bars and prestressed steel bars used in prefabricated structures shall comply with the provisions of Code for Design of Concrete Structures (GB500 10);
2. The calculation index of steel for fabricated structure shall comply with the provisions of Code for Design of Steel Structures (GB500 17); When the fabricated structural members are exposed to low temperature, the properties of the steel used should meet the requirements of atmospheric corrosion resistance and avoiding cold brittleness at low temperature.
3. The steel bars in beams, columns, walls and supports of assembled structures with seismic fortification requirements should be selected from the following brands according to the requirements of structural design on the strength, ductility, connection mode and construction adaptability of steel bars:
1) HRB400, HRB500, HRB400, HRB500, HRB335 and HRB335 are suitable for ordinary steel bars under longitudinal stress;
2) Prestressed steel wire, steel strand and prestressed threaded steel bar should be used for prestressed reinforcement;
3) Stirrups shall be reinforced with HPB300, HRB335, HRB400 and HRB500.
4, according to the first, second and third level seismic design of the frame and support members, the longitudinal stress of ordinary steel bar shall meet the following requirements:
1) The ratio between the measured tensile strength and the measured yield strength of steel bars should not be less than1.25;
2) The ratio of the measured yield strength of steel bars to the standard yield strength should not be greater than1.30;
3) The total elongation of steel bars under the maximum tension should not be less than 9%.
5. When steel welded mesh is used for prefabricated members, it shall conform to the current national standards "Technical Specification for Reinforced Welded Mesh Concrete Structure" (JJ114) and "Technical Specification for Application of Cold-drawn Low Carbon Steel Wire" (JJ19).
6. Lifting rings of prefabricated members shall be made of HPB300 steel bars without cold working. The embedded nuts or embedded suspenders used for hoisting prefabricated members and supporting slings shall be selected according to the corresponding product standards and application technical regulations.