Reinforcement of Old Prefabricated Panel Houses
The reinforcement of old prefabricated panel houses can be achieved through methods such as structural safety assessment, wall reinforcement, floor reinforcement, foundation reinforcement, adding supports, and adding structural columns. Details are as follows:
Structural safety assessment is a prerequisite for reinforcement. It requires a comprehensive inspection of the crack width of 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). This helps identify the location and extent of damage and provides a basis for subsequent reinforcement.
Wall reinforcement can be carried out using three methods: First, grouting reinforcement method, which involves injecting cement-based grout into the walls or foundations to fill voids and cracks, improving overall strength and stability, and enhancing seismic resistance. Second, steel bar mesh reinforcement method, which involves laying a steel bar mesh on the surface of walls or floors and covering it with cement mortar to form a composite structure, preventing deformation or crack propagation. Third, steel bar planting and grouting treatment, which involves drilling holes at key positions on the exterior walls, planting steel bars, and grouting to strengthen the load-bearing capacity and tensile properties of the walls, especially suitable for cases where the wall load-bearing capacity is insufficient.
Floor reinforcement requires addressing both panel joints and overall load-bearing capacity: Panel joint treatment involves removing the original filling material, implanting No. 6 deformed steel bars, and pouring C30 fine aggregate concrete to restore the connection strength of the panel joints. Steel plate bonding reinforcement method is suitable for floor cracks or deformation. It involves bonding steel plates to the bottom of the floor and anchoring them to improve load-bearing capacity and stability.
Foundation reinforcement can increase load-bearing capacity by expanding the foundation size, deepening the foundation, or adding steel bar meshes. At the same time, reinforcing agents or foundation sealing materials can be added to improve seismic resistance and prevent structural damage caused by foundation settlement.
Adding support reinforcement method includes two aspects: Before construction, a temporary support system needs to be erected, with steel pipe supports set every 1.2 meters along the length of the prefabricated panels. Key nodes should use H-shaped steel beams (with a cross-section of no less than 200*200 millimeters) for underpinning. Permanent supports can enhance the stability of walls or roofs by adding steel structural collars or diagonal braces.
Adding structural columns requires setting up structural columns with a cross-section of 240*240 millimeters at the four corners of the house. No. 6 and No. 8 steel bars should be used for reinforcement and reliably connected to the floor to form a frame structure, enhancing the overall lateral resistance capacity.
Precautions: Reinforcement materials must be compatible with the original structure. Construction details such as the adhesion of carbon fiber sheets and the tightness of steel structure connections must be strictly controlled. After reinforcement, quality inspection and acceptance must be carried out to ensure compliance with regulations. During construction, noise and dust should be controlled to minimize the impact on the surrounding area. Regular inspections and maintenance should be carried out to promptly identify and address potential problems.
