Bearing Capacity of Prefabricated Slab Structure Houses

The bearing capacity of prefabricated slab structure houses needs to be comprehensively determined based on their purpose, design specifications, and specific parameters, with no unified fixed value. Its load-bearing capacity is influenced by multiple factors such as the type of house, material and workmanship, slab thickness and span, as well as construction and installation. A detailed analysis is as follows:

I. Load-Bearing Standards for Houses with Different Purposes

1. Residential Buildings
   The standard value of uniformly distributed live loads on the floors of residential buildings such as ordinary houses, dormitories, and hotels is usually 2.0 kN/m² (approximately 200 kilograms per square meter). The prefabricated slabs for residential use available in the market are classified into different grades: the first-grade load-bearing capacity is 1 kN/m², the second-grade is 2 kN/m², and currently, it can reach up to the fourth grade. For example, if the floor slab of an ordinary residential building is designed according to the second grade, it can bear a uniformly distributed load of about 200 kilograms per square meter.

2. Public Buildings
   The standard values for offices, classrooms, conference rooms, and other public buildings are generally 2.0 kN/m² to 2.5 kN/m²; for hospital wards, laboratories, or rooms requiring the placement of heavy equipment, the load requirements may be increased to 3.5 kN/m² or even higher. For example, if a laboratory needs to install large-scale instruments, the floor slab should be designed according to higher standards.

3. Special Areas
   The load requirements for storage or vehicle passage areas such as warehouses and garages are significantly increased. Light truck passages may need to be designed according to 10-20 kN/m² to meet the dynamic load requirements during vehicle travel.

II. Key Factors Affecting Actual Load-Bearing Capacity

1. Materials and Workmanship
   The higher the concrete grade, the stronger the load-bearing capacity. For example, C30 concrete has higher compressive strength than C20 concrete. In addition, the application of prestressed technology can significantly improve the load-bearing capacity by pre-applying tensile stress to offset part of the load and reduce floor slab deformation.

2. Slab Thickness and Span
   Slab thickness directly affects load-bearing capacity: a 10-centimeter-thick prefabricated slab may only bear 150-250 kilograms per square meter, while a 12-centimeter-thick slab can reach 250 kilograms per square meter. When the span exceeds 4 meters or the supports are not firmly installed, the load-bearing capacity will significantly decrease, and it is necessary to improve it by adding supports or reducing the span.

3. Construction and Installation
   Construction details such as joint treatment, support anchoring, and grouting compactness directly affect the structural协同 load-bearing capacity. For example, if the joints are not grouted compactly, it may lead to local stress concentration and cause cracking.

III. Safety Precautions

1. Strictly Prohibit Overloading
   Adding partition walls, installing large fish tanks, or placing heavy equipment without professional calculation can easily cause floor slab cracking or even collapse. For example, stacking sand and gravel exceeding the designed load on the floor slab may cause structural damage.

2. Evaluate Old Houses Before Renovation
   Before renovating or adding floors to old houses, it is necessary to entrust a testing agency to evaluate the remaining load-bearing capacity and formulate a reinforcement plan. The performance of prefabricated slabs built in different eras varies significantly, and old-style channel slabs and modern prestressed hollow slabs need to be treated specifically.

3. Regular Inspection and Maintenance
   After long-term use, the load-bearing capacity of prefabricated slabs may decrease due to concrete carbonation and steel bar corrosion. It is necessary to regularly inspect and repair cracks, corrosion, and other problems.