Load-Bearing Standards for Prefabricated Slab Houses

There is no fixed value for the load-bearing standard of prefabricated slab houses, which is influenced by multiple factors. The common standard ranges are as follows:

Calculation Based on Uniformly Distributed Load

• Concrete Hollow Prefabricated Slabs: The national standard is 200 - 250 kilograms per square meter. For example, a hollow slab that is 3.6 meters long and 0.6 meters wide has an area of 2.16 square meters, with a total load-bearing capacity of approximately 432 kilograms (2.16 × 200). If the span is shortened to 2.4 meters, the load-bearing capacity per square meter can be increased to 250 kilograms; when the span exceeds 4.2 meters, it may drop to 150 - 180 kilograms.
• Solid Prefabricated Slabs: The load-bearing capacity is 250 - 300 kilograms per square meter. Solid slabs produced by large factories (such as Jianhua Construction Materials and China Railway 14th Bureau Group) can have a load-bearing capacity of up to 300 kilograms per square meter due to sufficient reinforcement and high concrete grades (C30 and above).
• Prestressed Prefabricated Slabs: When the span is within 3 meters, the load-bearing capacity is 300 - 400 kilograms per square meter; when the span exceeds 4 meters, the load-bearing capacity is 250 - 300 kilograms per square meter, which is 20% higher than that of ordinary prefabricated slabs of the same span.
• General Residential Houses: The load-bearing capacity of floor prefabricated slabs is approximately 200 kilograms per square meter, and they can actually withstand a surplus of about 300 kilograms.

Classification According to National Standard Grades

• Grade I Slabs: The standard value is 100 kilograms per square meter, suitable for placing light objects, daily furniture, and personnel movement, commonly used in civil buildings; there are also claims that their load-bearing capacity is 100 - 150 kilograms per square meter or 400 kilograms per square meter (possibly due to differences in standards or testing conditions).
• Grade II Slabs: The load-bearing capacity is 700 kilograms per square meter, commonly used in general residential buildings; there are also claims of 200 kilograms per square meter (which need to be confirmed in combination with specific standards).
• Grade III Slabs: The load-bearing capacity is 1000 kilograms per square meter, suitable for scenarios with high load-bearing requirements.
• Grade IV Slabs: The load-bearing capacity is over 400 kilograms per square meter, mostly used in special places such as gyms and factories.
• Industrial Prefabricated Slabs: The load-bearing capacity can reach 500 kilograms per square meter, meeting the needs of industrial production.

Other Influencing Factors

• Specifications and Span: The shorter the prefabricated slab, the stronger its load-bearing capacity; increasing the thickness (e.g., 10 cm compared to 8 cm) can enhance the load-bearing capacity.
• Reinforcement and Materials: The thickness, density of steel bars, and concrete grade directly affect the load-bearing capacity. Prefabricated slabs with sufficient reinforcement and high concrete grades have stronger load-bearing capacities.
• Load Type: Concentrated loads (such as heavy objects concentrated at one point) are more destructive to prefabricated slabs, while uniformly distributed loads can increase the upper limit of load-bearing capacity.