Reinforcement of Houses with Prefabricated Panel Walls Converted to Beams

The reinforcement of houses with prefabricated panel walls converted to beams requires following a scientific process and paying attention to key details. The specific steps and precautions are as follows:

I. Core Implementation Steps

1. Initial Structural Assessment
   A professional structural engineer should conduct a comprehensive inspection of the house, focusing on confirming the location of load-bearing walls and the feasibility of the renovation. Check the width of cracks in the prefabricated panels (reinforcement is required if the width exceeds 0.3 millimeters), the rust rate of connecting bolts between the prefabricated panels and the ring beams (replacement is required if the rust rate exceeds 30%), and analyze the overall stability of the house.

2. Customized Reinforcement Plan
   Design the material (such as reinforced concrete or H-shaped steel), dimensions, and installation method of the beams according to the structural characteristics of the house. The strength grade of the beams should comply with national standards. For example, the concrete strength of reinforced concrete beams should not be lower than C30, and the cross-sectional dimensions of H-shaped steel should meet the requirements of load-bearing capacity calculations.

3. Approval Process
   Submit a renovation application to the local housing and construction department and obtain a construction permit before starting work. Unauthorized renovation without approval may result in fines, forced restoration to the original state, and even affect the property transaction of the house.

4. Temporary Support Construction
   Before construction, set up steel pipe supports every 1.2 meters along the length of the prefabricated panels. Use H-shaped steel beams for underpinning at key nodes (the cross-section of the steel beams should be ≥ 200×200 millimeters) to ensure the stability of the floor slabs during wall removal and avoid the risk of collapse.

5. Demolition and Installation

   • Demolition Phase: Adopt a segmented cutting method (start from the middle and then move to the sides). The daily demolition volume should not exceed 30% of the total floor area, and monitor the stress changes in the support system in real-time.
   • Installation Phase: The new beams should be firmly connected to the original structure. For example, remove the original filling material at the panel joints, implant No. 6 threaded steel bars, and then pour C30 fine aggregate concrete; add constructional columns at the four corners of the house (with a cross-section of 240×240 millimeters, tied with No. 6 and No. 8 steel bars and connected to the floor slabs).

6. Inspection and Repair
   After construction, conduct a structural inspection to confirm that there are no looseness, cracks, or other defects in the connection between the beams and the original structure. Finally, repair the walls and carry out decoration.

II. Key Precautions

• Accurate Identification of Load-Bearing Walls: Load-bearing walls are usually ≥ 240 millimeters thick and produce a dull sound when knocked. They should be identified through architectural drawings or professional instruments. Misidentifying non-load-bearing walls as load-bearing ones may lead to structural instability.
• Selection of a Professional Team: The construction party should have qualifications in architectural structural design and construction, and a registered structural engineer should participate in the design and supervision throughout the process.
• Control of Construction Quality: The connection between the beams and the original structure should be reinforced to avoid stress concentration. The use of heavy hammers for impact demolition is prohibited to prevent impact on the foundation.
• Reduction of Construction Impact: Construction may generate noise and vibrations. Inform neighbors in advance and control the construction time. For high-rise residential renovations, assess the impact on lower-floor residents.