Fixation of House Prefabricated Panels

The fixation or reinforcement of house prefabricated panels can be achieved through the following methods, and the appropriate solution should be selected based on the degree of structural damage, usage requirements, and site conditions:

1. Grouting Reinforcement Method Inject cement-based or chemical grouting materials into cracks or voids in walls, foundations, or joints of prefabricated panels using pressure equipment. After curing, the grouting material forms a dense structure that fills voids, enhances overall bonding strength, improves seismic performance, and prevents further deformation. This method is suitable for areas with small crack widths (≤0.3mm) or localized loose regions, and care must be taken to control grouting pressure to avoid secondary damage.

2. Steel Mesh Reinforcement Method Lay a steel mesh with a diameter of 4-8mm on the surface of the prefabricated panel or wall, and then cover it with fine aggregate concrete after fixing it with anchors or planted rebars. The steel mesh and concrete form a composite structure that significantly improves flexural and shear resistance, making it particularly suitable for situations where the floor slab has insufficient load-bearing capacity or the wall has severe cracking. During construction, ensure that the spacing between the steel mesh is uniform (usually 150-300mm) and the concrete thickness is not less than 40mm.

3. Carbon Fiber Sheet Bonding Reinforcement Method Apply high-strength carbon fiber sheets (with a tensile strength of ≥3400MPa) along the stress direction of the prefabricated panel and fix them at both ends with U-shaped strips. The carbon fiber sheets can compensate for the tensile performance of the original structural steel bars and are suitable for scenarios where the deflection at the bottom of the panel is excessive or through cracks appear. Construction points include: leveling the base layer, ensuring a lap length of the carbon fiber sheets of ≥200mm, waiting for the previous layer to cure when applying multiple layers, and finally applying a protective coating to prevent aging.

4. Section Enlargement Reinforcement Method Pour an additional concrete layer (with a thickness of 50-100mm) on the surface of the prefabricated panel, equipped with a double-layer bidirectional steel mesh. The additional layer is connected to the original panel through planted rebars (with a diameter of 10-12mm and a spacing of 300-500mm) or shear keys to form an overall load-bearing structure. This method can increase the structural load-bearing capacity by 30%-50%, but attention must be paid to the impact of the self-weight of the additional layer on the original structure, making it suitable for floor slab reinforcement with large spans or increased loads.

Construction Precautions:

• Conduct structural inspections before reinforcement to clarify the causes of damage (such as foundation settlement or overload).
• Ensure that material properties meet the requirements of the "Code for Design of Strengthening Concrete Structures" (GB50367).
• The construction environment temperature should not be lower than 5°C, and the relative humidity should not exceed 85%.
• After reinforcement, conduct load-bearing tests and long-term deformation monitoring, and refer to the "Code for Acceptance of Construction Quality of Building Structure Strengthening Engineering" (GB50550) for acceptance standards.