Quality Inspection Standards for Prefabricated Houses

The quality inspection standards for prefabricated houses cover three aspects: structural inspection, component acceptance, and testing and appraisal.

I. Preliminary Inspection of Safety Hazards in Old Urban Prefabricated Panel Houses

1. Structural Integrity and Foundation: Check for signs of foundation settlement, such as uneven ground levels around the house and diagonal cracks at the base of walls; visually assess whether the house is tilted or twisted.
2. Special Inspection of Core Components:
   • Prefabricated Floor Slabs: Focus on inspecting cracks at the bottom of the slabs, deflection and deformation, and damage at the ends.
   • Load-Bearing Walls: Examine for stress cracks and weathering phenomena, and confirm whether ring beams and structural columns are installed to enhance structural stability.
   • Node Connections: Check whether the support of prefabricated slabs on walls is secure, and whether there are separations or cracks at the corners and intersections of walls.
3. Unauthorized Renovations and Usage Environment: Verify whether there have been unauthorized removals of load-bearing walls, enlargements of door and window openings, or additions of floors on rooftops or heavy loads placed on floor slabs; if the residence is converted into a crowded place, assess the risks associated with increased live loads.

II. On-Site Acceptance and Inspection of Concrete Prefabricated Components

1. Performance Inspection of Flexural Members:
   • Inspection Site: Conduct tests at the prefabricated component production plant or on the construction site.
   • Inspection Quantity: For each type of component, every 1000 pieces constitute a batch, and one piece is randomly selected for structural performance inspection.
   • Inspection Method: According to Appendix B of the "Code for Acceptance of Constructional Quality of Concrete Structures", test the bearing capacity, deflection, crack width, or crack resistance.
2. Management of Exempted Components: If structural performance inspections are not conducted, on-site supervision or physical inspections must be implemented:
   • The construction unit or supervision unit shall assign representatives to supervise production at the plant and fulfill registration and clock-in procedures.
   • When there is no on-site supervision, upon arrival, inspect the quantity, specifications, spacing, and protective layer thickness of the main load-bearing steel bars, as well as the concrete strength.

III. Standards for House Quality Testing and Appraisal (Taking Shanghai as an Example)

1. Types of Testing and Appraisal: Include inspections for condition, safety, damage trends, seismic capacity, and dangerous houses, with the addition of special inspections for exterior walls and identification of repairs to load-bearing structures.
2. Adjustments to Technical Content: Increase on-site testing of the performance of reinforcement materials, remove some outdated content; introduce structural health monitoring and improve house deformation measurement and long-term monitoring systems.