Technical Specifications for Prefabricated Houses

The technical specifications for prefabricated houses cover material, design, construction, and acceptance criteria, with specific requirements as follows:

I. Material Requirements

1. Main Component Materials

   • Prefabricated Wall Panels: Thickness 50-100mm, concrete strength ≥ C30, with built-in φ6@200 bidirectional steel reinforcement mesh, and embedded parts deviation ≤ 5mm.
   • Prefabricated Roof Panels: For spans ≤ 4.2m, thickness ≥ 120mm, equipped with φ8@150 longitudinal reinforcement + φ6@200 transverse reinforcement, and load-bearing capacity test load ≥ 1.5 times the design live load.
   • Load-Bearing Framework: Steel structural columns use C-section steel (100×50×20×3mm) or square tubes (80×80×3mm), with yield strength ≥ 235MPa, surface hot-dip galvanized (zinc layer ≥ 85μm); connectors are M12 high-strength bolts (Grade 8.8), with tightening torque 45-50N·m.

2. Auxiliary Materials

   • Waterproof Membrane: SBS modified bitumen, thickness ≥ 3mm, tensile strength ≥ 800N/50mm, elongation ≥ 30%.
   • Sealant: Silicone weather-resistant sealant, displacement capacity ±25%, bond strength ≥ 0.6MPa.
   • Insulation Wool: Centrifugal glass wool, density 48kg/m³, thermal conductivity ≤ 0.042W/(m·K), water repellency ≥ 98%.
   • Grouting Material: Non-shrink CGM-4 type, initial flowability ≥ 320mm, 28d compressive strength ≥ 60MPa.

3. Concrete and Steel Reinforcement

   • Main structural concrete grade ≥ C30, main reinforcement diameter ≥ 8mm, spacing ≤ 200mm; seismic resistance must meet Grade 7 requirements.

II. Design Requirements

1. Structural Design
   • Comply with national building codes, wall thickness: load-bearing walls ≥ 150mm, non-load-bearing walls ≥ 100mm; roof slope ≥ 5%, internal and external corners to have R50mm rounded fillets.
2. Function and Layout
   • Meet functional requirements, with reasonable spatial layout and aesthetically pleasing appearance.

III. Construction Requirements

1. Foundation Construction
   • Site compaction coefficient ≥ 0.93, drainage slope ≥ 2%; foundation bearing capacity characteristic value fak ≥ 120kPa; concrete strip foundation curing ≥ 7 days.
2. Main Structure Installation
   • Lifting equipment rated load ≥ 1.5 times the component's self-weight; installation verticality deviation ≤ H/1000 and ≤ 20mm; joints must pass a 3-hour water spray test (water volume ≥ 2L/(min·m²)).
3. Construction Safety
   • Strictly adhere to operating procedures to prevent accidents such as falls from heights and object strikes.

IV. Acceptance Criteria

1. Process acceptance shall be conducted in stages to ensure compliance with design requirements.
2. Special environmental adaptability: Pass Grade 7 seismic test, with wall material combustion performance reaching Class A.

Note: Technical parameters should be adjusted according to project geological conditions, and it is recommended to commission a professional institution for verification.