Load-Bearing of Prefabricated Slab Structure Houses

The load-bearing standards for prefabricated slab structure houses need to be comprehensively determined based on the house's purpose, structural parameters, and relevant regulations, with no single fixed value. Here is a detailed analysis:

I. Classification Basis for Load-Bearing Standards
According to the "Building Structural Load Code" (GB 50009), the standard values of live loads on the floors of prefabricated slabs are classified by purpose:

1. Residential Buildings (such as residences, dormitories, hotels): 2.0 kN/m² (approximately 200 kilograms per square meter), meeting the needs of daily personnel activities and the placement of ordinary furniture.
2. Public Buildings (such as offices, classrooms, conference rooms): 2.0-2.5 kN/m², considering scenarios with dense personnel or equipment usage.
3. Special-Function Rooms (such as hospital wards, laboratories): 3.5 kN/m² or higher, requiring the bearing of heavy loads such as medical equipment or laboratory instruments.
4. Storage and Traffic Areas (such as warehouses, garages): Light truck aisles require 10-20 kN/m² to cope with dynamic vehicle loads and cargo stacking.

II. Factors Affecting Load-Bearing Capacity

1. Material and Structural Parameters:

   • The concrete strength grade (C20-C40) directly affects the compressive performance, with higher strength grades resulting in stronger load-bearing capacity.
   • The steel bar configuration (diameter, spacing) determines the tensile and bending resistance. Prestressed hollow slabs (such as the YKB series) enhance crack resistance through pre-compression stress.
   • Slab thickness and span: Increasing the slab thickness can improve the load-bearing capacity, but increasing the span reduces the bending stiffness, necessitating compensation through increased reinforcement or reduced span.

2. Construction Quality:

   • The grouting density between slab gaps affects the overall collaborative load-bearing. Insufficient grouting can easily lead to concentrated load-bearing on a single slab.
   • Support anchoring measures (such as bedding mortar, welding) ensure the effective transfer of loads to walls or beams and columns, avoiding local damage.

III. Usage and Renovation Precautions

1. Load Differentiation:

   • Dead Loads (structural self-weight, decoration layers) need to be considered once in the design, and any subsequent increases require recalculation.
   • Live Loads (personnel, furniture, equipment) need to be strictly controlled, and overloading is strictly prohibited (such as stacking heavy objects, installing large fish tanks).

2. Renovation Restrictions:

   • No additional partition walls or changes in room purposes are allowed without professional calculation, as this may lead to slab cracking due to sudden load changes.
   • Before renovating or adding floors to old houses, a testing agency must be commissioned to evaluate the remaining load-bearing capacity of the prefabricated slabs. If necessary, reinforcement measures such as pasting carbon fiber sheets, increasing the cross-sectional area, or adding steel beam supports should be adopted.

IV. Safety Recommendations
If heavy equipment needs to be arranged or structural modifications are required in a prefabricated slab house, it is advisable to consult a structural engineer first to determine through calculation whether reinforcement or layout adjustments are needed. Do not proceed with construction based on experience alone to avoid structural safety hazards.