Renovation of Prefabricated Panel Buildings

The renovation of prefabricated panel buildings can be achieved through methods such as structural reinforcement, wall removal and beam replacement, and indoor and outdoor renovation, but it is necessary to strictly follow technical specifications and ensure safety.

I. Structural Reinforcement

1. Safety Assessment and Inspection: Before renovation, a comprehensive assessment of structural safety is required, with a focus on inspecting the width of cracks in the prefabricated panels (special treatment is needed if the width exceeds 0.3 millimeters) and the connection status between the prefabricated panels and the ring beams (bolts with a rust rate exceeding 30% need to be replaced).
2. Temporary Support System: During construction, temporary supports need to be erected. Steel pipe supports should be placed every 1.2 meters along the length of the prefabricated panels, and H-shaped steel beams (with a cross-section of ≥200*200 millimeters) should be used for underpinning at key nodes to ensure structural stability during construction.
3. Panel Joint Treatment: Remove the original joint-filling materials, implant No. 6 deformed steel bars, and pour C30 fine aggregate concrete to enhance the connection strength of the panel joints.
4. Addition of Structural Columns: Add structural columns (with a cross-section of 240*240 millimeters) at the four corners of the building, and use No. 6 and No. 8 steel bars for reinforcement and connect them to the floor slab to improve the overall seismic performance.

II. Wall Removal and Beam Replacement

1. Segmented Removal Principle: Follow a symmetrical removal sequence of "middle first, then sides", with a daily removal amount not exceeding 30% of the total floor area to avoid structural instability caused by sudden load changes.
2. Real-time Monitoring: During the removal process, monitor the stress changes in the support system. It is prohibited to use heavy hammers for impact removal to prevent damage to the foundation structure.

III. Indoor and Outdoor Renovation

1. Entrance Door Renovation: The size of the entrance door can be enlarged to enhance the sense of space, but it is necessary to ensure a firm connection between the door frame and the wall and avoid damaging the load-bearing structure.
2. Roof Renewal: After removing the original wooden roof, pour a new concrete roof. Ensure the construction quality of the waterproof layer and reserve interfaces for the laying of roofing materials (such as tiles, metal panels, etc.).
3. Exterior Wall Treatment: After completely removing the original exterior wall, repaint it and carry out steel bar planting and grouting treatment to enhance the load-bearing strength and tensile performance of the wall and prevent cracking or peeling.

IV. Precautions

1. Policy Restrictions: The design life of prefabricated panel buildings is about 40 years. Since 2023, the country has prohibited the construction, renovation, and expansion of such buildings in urban built-up areas. Existing buildings need to be gradually demolished or renovated according to actual conditions.
2. Professional Guidance: The renovation process requires knowledge of building structures. It is recommended to have a designer provide full technical guidance throughout the process and cooperate with the owner for acceptance to ensure the scientificity and safety of the construction.