Specification Requirements for Prefabricated Beam and Slab in Houses

The specification requirements for prefabricated beams and slabs in houses mainly cover aspects such as storage, bearing length, as well as design, fabrication, transportation, and stacking. Details are as follows:

I. Storage Requirements
The storage site must be solid, flat, and well-drained to prevent cracking or deformation of the components due to uneven foundation settlement. During stacking, ensure accurate support positions and align the wooden pads on different layers to maintain uniform force distribution. Beam components can be stacked 2-3 layers high, while slab components should not exceed 6 layers to prevent damage to the bottom components from excessive stacking. Slab components should preferably be stored upright or on dedicated supports with an inclination angle of no less than 70° to reduce bending stress caused by self-weight. During storage, protect the finished components, such as by covering them with protective materials or setting up warning signs, to avoid collision, contamination, or human-induced damage.

II. Bearing Length Requirements
The connection between the prefabricated slab and the supporting structure must meet the minimum bearing length requirements to ensure reliable load transfer. When the prefabricated slab is placed on a brick wall, the minimum bearing length must not be less than 100 millimeters; if placed on a reinforced concrete ring beam, it must not be less than 80 millimeters. If a connection method involving extending steel bars from the slab end for tying and filling with concrete is used, the bearing length can be reduced to 40 millimeters, provided that two conditions are met: first, the slab joint width must be greater than 80 millimeters to ensure adequate filling of the concrete; second, the strength grade of the filling concrete must reach C20 or above to ensure the shear and tensile resistance of the connection area.

III. Design, Fabrication, Transportation, and Stacking Requirements
According to the 'Technical Standard for Prestressed Assembled Concrete Frame Structures', the design of prefabricated components must consider the seismic fortification intensity (applicable to areas with an intensity of 9 degrees or below), specifying key parameters such as connection joint details and prestressed reinforcement layout. During fabrication, strictly control indicators such as concrete strength and prestressed tension values to ensure the load-bearing capacity of the components meets design requirements. During transportation, select specialized vehicles based on the shape of the components and take fixing measures to prevent sliding or overturning. During stacking, follow the aforementioned storage requirements and classify the components by type to avoid damage from mixed stacking. Additionally, the standard specifies construction and acceptance procedures to ensure quality control throughout the process from fabrication to installation.