Maintenance of Prefabricated Slab Houses

The maintenance of prefabricated slab houses should be systematically carried out from five aspects: comprehensive inspection, structural reinforcement, functional upgrading, exterior wall treatment, and construction safeguards, as detailed below:

1. Comprehensive Inspection It is necessary to entrust a professional inspection agency to conduct a thorough 'check-up' of the house using specialized instruments, focusing on issues such as wall cracks, steel bar corrosion, and foundation settlement. Based on the inspection results, a targeted plan should be formulated: if the wall cracks are minor, grouting repair can be used; for severe cracks, steel plate reinforcement is required; roof leaks necessitate the relaying of waterproof layers; and unstable foundations require pile driving for reinforcement. This step is the foundation of maintenance, and it is essential to ensure accurate inspection data to avoid overlooking potential hazards.

2. Structural Reinforcement

• Crack Treatment: When the width of cracks in the prefabricated slabs exceeds 0.3 millimeters, the original filling material should be removed, No. 6 threaded steel bars should be implanted, and C30 fine aggregate concrete should be poured. At the four corners of the house, structural columns (with a cross-section of 240*240 millimeters) should be added, reinforced with No. 6 and No. 8 steel bars and connected to the floor slabs to enhance overall stability.
• Connection Repair: The connection status between the prefabricated slabs and the ring beams should be inspected. If the bolt corrosion rate exceeds 30%, timely replacement is required. For repairable houses, techniques such as adding ring beam structural columns, applying carbon fiber cloth, and casting composite layers can be used to improve load-bearing capacity. For example, Beijing Midas Company proposed pouring a reinforced concrete composite layer at the joints of prefabricated slabs, which can significantly enhance the load-bearing capacity of the floor slabs.

3. Functional Upgrading

• Sound Insulation Optimization: By installing sound insulation panels and replacing single-glazed windows with double-glazed ones, the sound insulation effect can be improved by 70%, enhancing living comfort.
• Comprehensive Renovation: In conjunction with the renovation of old residential areas, efforts should be made to simultaneously install elevators, update water and electricity pipelines, and improve thermal and sound insulation. For example, in the renovation of the Neijiang large-panel houses in Shanghai, a 'one-door' design was adopted to solve the problem of shared kitchens and bathrooms, and balconies were added to improve space utilization.

4. Exterior Wall Treatment The original exterior wall tiles should be removed, and the walls should be repainted and reinforced with steel bar implantation and grouting to enhance the load-bearing strength and tensile properties of the walls. This step can prevent the risk of exterior wall detachment while improving the aesthetic appeal of the building.

5. Construction Safeguards

• Support System: Before construction, temporary supports should be erected, with steel pipe supports placed every 1.2 meters along the length of the prefabricated slabs. Key nodes should use H-shaped steel beam underpinning (with a cross-section of no less than 200*200 millimeters) to ensure construction safety.
• Demolition Specifications: The principle of 'middle first, then sides' should be followed, with segmented and symmetrical demolition. The daily demolition volume should not exceed 30% of the total floor slab area. The stress changes in the support system should be monitored in real-time, and heavy hammer impact demolition is prohibited to avoid secondary damage to the foundation structure.