Single-Story Prefabricated Slab House Design

The design of single-story prefabricated slab houses requires an assessment of applicability based on specific needs. The key points are as follows:

Applicable Scenarios

1. Temporary Buildings: Prefabricated slabs offer a short construction period, with the main structure taking only 3-7 days to erect, making them suitable for temporary housing on construction sites and emergency shelters.
2. Budget-Limited Projects: Costs are 30%-50% lower than those of cast-in-place structures, making them ideal for rural self-built houses or simple warehouses where cost is a concern.
3. Areas with Poor Geological Conditions: In soft soil foundations, the lighter weight of prefabricated slabs reduces the risk of uneven settlement, but proper foundation treatment is essential.

Key Considerations

1. Load-Bearing Limitations: The load-bearing capacity of a single slab is ≤200kg/㎡. It is prohibited for use with heavy roofs (such as concrete tiles) or for adding a second story, as this can easily lead to structural damage.
2. Joint Treatment: Gaps between slabs must be filled with C20 fine aggregate concrete to prevent leakage or stress concentration caused by gaps.
3. Seismic Performance: In areas with a seismic fortification intensity of 7 degrees or higher, steel reinforcement (such as adding diagonal braces or ring beams) is required; otherwise, the structure is prone to collapse during earthquakes.
4. Durability: The actual service life of prefabricated slabs is about 10 years. Issues such as cracking and steel bar corrosion may occur due to aging, requiring regular inspection and maintenance.

Construction Points

1. Foundation Requirements: A 30cm thick gravel cushion plus a 15cm plain concrete leveling layer are required to ensure a flat ground surface with adequate bearing capacity.
2. Installation Sequence: Install slabs from the corners of the house towards the center, using a staggered joint method to enhance overall stability.
3. Waterproofing: Additional SBS modified bitumen waterproofing layers must be laid on roof slabs to prevent rainwater penetration and internal dampness.

Material Selection

1. Specifications: Common slab types are 3-6m long, 0.5-1.2m wide, and 12-18cm thick. The appropriate size should be selected based on the span.
2. Strength Grade: The concrete strength should be no less than C30 to ensure adequate flexural and shear performance.
3. Reinforcement Requirements: Main reinforcement bars should have a diameter of ≥8mm with a spacing of ≤15cm, and distribution bars should have a diameter of ≥6mm with a spacing of ≤25cm to prevent cracking.

Damp-Proofing Treatment (Ground Floor)

If using a prefabricated slab elevated layer for damp-proofing, backfill soil to a height of 30-50cm from the ground surface and compact it after pouring the ground beam to prevent direct contact between soil moisture and the slab bottom. However, it should be noted that prefabricated slabs generally have poor seismic performance and are prone to leakage and cracking. In humid or rainy areas, the use scenario should be carefully evaluated, and other damp-proofing measures (such as laying damp-proof membranes) should be considered if necessary.