Specifications for Prefabricated Concrete Houses

The specifications for prefabricated concrete houses cover dimensions, component parameters, allowable deviations, and appearance quality requirements, as detailed below:

I. Common Dimensions

Single-story houses are primarily in the form of length × width, with common dimensions of 6m × 3m, 8m × 3m, 10m × 3m, and 12m × 3m. The width ranges from 3 to 6 meters, the height from 2.5 to 5 meters, and the length can extend to tens of meters. Multi-story houses are represented by length × width × height, such as 7.2m × 3.3m × 3.0m and 8.1m × 3.3m × 3.0m. The total height for a two-story house is 4 to 6 meters (2.5 to 3 meters per floor), and for a three-story house, it is 6 to 9 meters (2.5 to 3 meters per floor).

II. Specific Component Parameters

1. Prefabricated Concrete Panels: For residential use, the span is mostly 4.2 meters (customization required for longer spans). The width is primarily 500mm or 600mm, and the thickness is commonly 120mm or 150mm.
2. House Components: The wall thickness is ≥150mm, and the eave length is adjustable from 0 to 1200mm.

III. Allowable Dimensional Deviations

1. Length Deviation: ±10mm for lengths ≤6000mm, and ±15mm for lengths >6000mm.
2. Width Deviation: ±25mm for widths ≤6000mm, and ±20mm for widths >6000mm.
3. Height Deviation: ±15mm regardless of whether the length exceeds 6000mm.
4. Wall Thickness Deviation: -2mm to +5mm.
5. Flatness: Lateral bending and warping ≤20mm.
6. End Face Tilt: ≤5mm.
7. Door and Window Position Deviation: ±15mm.
8. Embedded Part Position Deviation: ±5mm.
9. Lifting Ring Exposed Height Deviation: ±10mm.
10. Protective Layer Thickness Deviation: -2mm to +5mm.

IV. Appearance Quality Requirements

1. Cracks: No cracks penetrating the wall thickness are allowed on the surface. Cracks with a width >0.20mm or depth >3mm on the inner or outer surface (excluding surface crazing and mortar shrinkage cracks) must be treated.
2. Local Damage: Repair is allowed if the damaged area is ≤1/50 of the outer surface area and the steel reinforcement framework is not exposed.
3. End Face Tilt: The tilt must be ≤5mm.
4. End Face Impact Damage: Repair is allowed if the longitudinal length is ≤100mm and the transverse width is ≤50mm.
5. Surface Flatness: The local concave-convex depth must be ≤5mm.
6. Honeycombing, Pitting, and Adhesion: Repair is allowed if the adhesion depth is ≤10mm and the total area is ≤8% of the inner/outer surface area.
7. Joint Leakage: Repair is allowed if the leakage depth is ≤ the protective layer, the length of a single leak is ≤300mm, and the cumulative length is ≤10% of the house length.

All parameters must strictly adhere to design specifications to ensure structural safety and functionality.