Renovation and Demolition of Prefabricated Slab Houses
The renovation and demolition of prefabricated slab houses involve various aspects such as renovation, demolition policies, and compensation. Here is a detailed introduction:
Renovation
Take the old house renovation project in Zhongxing Town, Chongming as an example. When renovating a 30-year-old prefabricated slab structure house, the original wooden roof is completely removed, and a new concrete roof is poured while maintaining the original height. This ensures waterproofing, structural durability, and stability, and also meets the requirements for laying various roofing materials. Before construction, the structural team conducts a comprehensive structural safety assessment of the old house, focusing on checking the crack width at the prefabricated slab production points. Special treatment is required if the crack width exceeds 0.3 millimeters. The connection status between the prefabricated slabs and the ring beams is also inspected, and bolts with a rust rate exceeding 30% need to be replaced. The original exterior wall tiles are removed, and the exterior walls are repainted and treated with steel bar planting and grouting to enhance the load-bearing strength and tensile properties of the walls. During the construction preparation phase, a temporary support system is erected, with steel pipe supports placed every 1.2 meters along the length of the prefabricated slabs. Key nodes use H-shaped steel beams for beam replacement (the steel beam section is greater than or equal to 200200 millimeters). The original filling materials at the slab joints identified by the structural inspection are removed, No. 6 deformed steel bars are implanted, and C30 fine aggregate concrete is poured. Construction columns are added at the four corners of the house (the construction column section is generally 240240 millimeters, with No. 6 and No. 8 steel bars tied together and connected to the floor slab). The construction sequence follows the principle of starting from the middle and then moving to the sides, with segmented demolition and cutting. Symmetrical demolition is maintained, and the daily demolition volume does not exceed 30% of the total floor area. During the demolition process, the stress changes in the support system are monitored in real-time, and the use of heavy hammers for impact demolition is prohibited.
Demolition Policies
In 2025, a new national policy will be introduced, prioritizing the demolition of three types of houses: First, houses identified as D-grade dilapidated buildings by professional institutions, which have damaged main structures, such as foundation settlement exceeding 5 centimeters, cracks in load-bearing walls wider than 1 millimeter, and seismic resistance levels less than 70% of the current standards. Second, houses that are difficult to withstand natural disasters, such as buildings with seismic resistance levels less than 70% of the current standards or houses vulnerable to floods. Third, houses that affect urban planning, such as residential buildings located within the planning scope of major infrastructure projects like subways and elevated roads.
Compensation
For the demolition of prefabricated slab houses, the government offers multiple compensation methods. The monetary compensation plan is not less than 110% of the market price of surrounding commercial housing. Property rights exchange has innovated the traditional resettlement method. In Handan, residential buildings are replaced at a ratio of 1:1.1, and homestead houses at a maximum ratio of 1:1.2, with a guaranteed minimum area of 30 square meters per person. The housing voucher resettlement system is also being implemented. In addition, the policy supports the "self-renovation and original-site reconstruction" of old houses, allowing the new house type or the actual usable area after renovation to increase by up to about 30%.
