How to Design Prefabricated House Slabs

The design of prefabricated house slabs covers multiple aspects, including production process, dimensions, load-bearing capacity, classification and design purposes, and application design considerations.

Production Process: First, a hollow mold is made using wooden planks. Reinforcing bars are then reasonably arranged in the hollow part of the mold, which is subsequently filled with cement. After the cement dries, the wooden planks are knocked away, leaving the prefabricated slab.

Dimensions:

• Span: The longest prefabricated slab for residential use is 4.2 meters, not following a modular pattern. If the length exceeds this, customization is required.
• Width: Common specifications are primarily 500mm and 600mm, with types such as four-hole 400mm and five-hole 500mm.
• Thickness: Common thicknesses are 120mm and 150mm.
• Length: Generally designed according to a 300mm modular pattern, such as 3000, 3300, 3600, 3900, 4200, etc. There are also special lengths like 3800 and 4000, with the longest ordinary slab being 4200.

Load-Bearing Capacity: Generally, residential buildings use Class I and Class II slabs. Class I slabs can bear a live load of 1kN/m², while Class II slabs can bear a live load of 2kN/m². In the southwest region, the minimum requirement is Class IV slabs, which can bear a live load of 4kN/m².

Classification and Design Purposes: Prefabricated slabs are divided into solid and hollow types. Hollow prefabricated slabs are made because the hollow parts of the slab do not bear force. By leaving these non-load-bearing areas hollow, the weight of the prefabricated slab itself can be reduced, while also saving materials and costs. However, the head of the hollow slab must bear the load transmitted from above, so a block is added at the head. There are also regulations for YKB slab joints: generally, joints less than 30mm are unqualified, 30-50mm are qualified, joints from 50-110mm require reinforcement, and joints larger than 110mm but less than 500mm (exceeding the标志 length of one slab, with 标志 lengths of 500, 600, 900 available) can be made into slab strips by adding another slab.

Application Design Considerations: When designing a house using prefabricated slabs, full consideration must be given to structural safety to ensure the house can withstand various loads and external forces. At the same time, spatial layout should be reasonably planned to meet residential and usage needs. Additionally, waterproofing and moisture-proofing treatments should be carried out to prevent moisture erosion from affecting the service life of the prefabricated slabs. In terms of interior decoration, given the limitations of the prefabricated slab structure, a minimalist style should be adopted to avoid excessive complex shapes and decorations, thereby reducing the structural burden.