Specification for Steel Bar Erection in Prefabricated Houses
The specification for steel bar erection in prefabricated houses mainly includes aspects such as the spacing and arrangement methods of steel bars in prefabricated floor slabs, as well as the technical specifications for prefabricated monolithic reinforced concrete structures.
Spacing Specifications for Steel Bars in Prefabricated Floor Slabs: The diameter of the main steel bars arranged horizontally should be no less than 6mm, and the spacing should be less than or equal to one-fourth of the floor slab thickness. For example, the spacing of 6mm steel bars should be controlled within 150mm. Shear bars perpendicular to the horizontal bars should be arranged longitudinally and transversely according to the load magnitude and floor slab thickness. Grid steel bars should meet the reinforcement requirements caused by construction deviations and should be arranged with a certain degree of cross-staggering to ensure the stability and integrity of the steel bar structure and enhance the floor slab's ability to resist external forces.
Arrangement Methods for Steel Bars in Prefabricated Floor Slabs: The selection of steel bar diameters should be based on design drawings and floor slab dimensions. The diameters of steel bars at the connections between beams and slabs are usually larger than those in the slabs, with common diameters including 8, 10, 12, 16, and 20mm. The arrangement of steel bars at beam-slab connections should be controlled within the connection width range, using a steel bar wrapping method where the steel bars are bent towards the beam and arranged along its length. When arranging the steel bar mesh in the slab, first wrap the reinforcement loops around the transverse bridge bars and then arrange the mesh according to the slab dimensions and design requirements. Generally, steel bar bridges are set at the outer edges of the slab, with a width greater than the diameter of a single steel bar and arranged as parallel as possible to improve the slab's load-bearing capacity. When the slab length exceeds the maximum allowable length specified in the design, diagonal steel bars should be set at the slab ends according to the design requirements, distributed at a 45° angle to enhance the slab's load-bearing capacity.
Technical Specifications for Prefabricated Monolithic Reinforced Concrete Structures: This specification is comprehensive, covering basic design provisions, connection forms and details, overall structural analysis, component and connection design, non-structural components, fabrication and inspection of prefabricated components, and installation construction and acceptance. This specification is under the jurisdiction of the Shenzhen Housing and Construction Bureau, with Vanke Co., Ltd. responsible for its specific interpretation. It provides detailed standards and bases for the design, construction, and acceptance of prefabricated monolithic reinforced concrete structures.
