Renovation and Reinforcement of Prefabricated Slab Houses

The renovation and reinforcement of prefabricated slab houses should be systematically carried out from multiple aspects, including structural assessment, roof treatment, wall reinforcement, slab joint treatment, temporary support, and construction sequence. The specific steps are as follows:

1. Structural Safety Assessment
Before renovation, a professional agency should be commissioned to conduct a comprehensive inspection, focusing on the crack width of the prefabricated slabs (special treatment is required if the width exceeds 0.3 millimeters) and their connection status with the ring beams. If the bolt corrosion rate exceeds 30%, they should be replaced with standard connectors. The assessment results will determine the targeted nature of the subsequent reinforcement plan, such as whether additional supports are needed or the load distribution should be adjusted.

2. Roof Renovation
For the leakage problem caused by the splicing joints of the prefabricated slab roof, two solutions can be adopted:

• Integral Pouring: Re-pour the concrete roof to enhance the overall structural integrity and provide a foundation for subsequent laying of waterproof layers or new roofing materials (such as photovoltaic panels).
• Systematic Waterproofing: Form multiple waterproof barriers through comprehensive obstacle removal, base layer repair, rigid filling of slab joints, laying of thickened waterproof membranes, and specialized waterproofing reinforcement of gutters to eradicate recurrent leakage problems.

3. Wall Reinforcement
After removing the original exterior wall tiles, two-step treatment is required:

• Rebar Planting and Grouting: Improve the wall's tensile performance and load-bearing strength by planting rebars and injecting high-strength grouting material.
• Adding Structural Columns: Add 240*240-millimeter structural columns at the four corners of the house, using No. 6 and No. 8 rebars for reinforcement and reliably connecting them to the floor slab to form a frame and enhance overall stability.

4. Slab Joint Treatment
After removing the original joint filling material, plant No. 6 threaded rebars and inject C30 fine aggregate concrete to ensure that the slab joints form an integral load-bearing structure with the prefabricated slabs. This step can effectively reduce structural safety hazards caused by slab joint cracking.

5. Temporary Support System
Before construction, temporary supports should be erected:

• Set up steel pipe supports every 1.2 meters along the length of the prefabricated slabs, and use H-shaped steel beams with a cross-section of no less than 200*200 millimeters for key nodes.
• The support system should be calculated and verified for its load-bearing capacity to ensure structural safety during construction.

6. Construction Sequence Control
Follow the principle of 'middle first, then sides, and symmetrical removal', with a daily removal amount not exceeding 30% of the total floor slab area. During the removal process, continuously monitor the stress changes in the support system. It is strictly prohibited to use heavy hammers for impact removal to avoid shock damage to the foundation.

Precautions: All materials must comply with national standards (such as C30 concrete and national standard thickened waterproof membranes). The construction process should be carried out by a professional team, and detection data should be regularly reported to the regulatory authorities to ensure that the reinforcement effect meets current seismic and safety regulations.