Old Prefabricated Panel Houses
Prefabricated panel houses in old buildings are structures primarily constructed using prefabricated panels. They suffer from issues such as weak earthquake resistance, poor sound and thermal insulation, and low living comfort. Since 2022, China has implemented renovation policies to repair and upgrade these houses.
Basic Information on Prefabricated Panel Houses
Prefabricated panels are cement components manufactured in factories. They are created by nailing wooden models, arranging steel bars, and pouring cement. These panels come in two types: solid and hollow, with the latter achieving lightweight construction by reducing non-load-bearing concrete. This building method originated in the early 20th century and was primarily used for floor slabs and roof insulation layers. In China, residential buildings constructed before 1985 often adopted this structure. The construction process resembles building with “LEGO blocks,” where pre-fabricated cement panels are assembled piece by piece, enabling fast construction and low costs, which once addressed housing shortages.
Existing Problems with Prefabricated Panel Houses
- Weak Earthquake Resistance: These houses typically have a design lifespan of about 40 years. Many now exceed this lifespan, with some experiencing extensive peeling of wall finishes, numerous cracks, and even becoming dangerous buildings at risk of collapse.
- Poor Sound and Thermal Insulation: In winter, interiors remain cold despite heating devices, while summers are stuffy with poor ventilation. Sound insulation is inadequate, leaving residents with no privacy, as conversations and TV sounds from neighbors are often clearly audible.
- Low Living Comfort: Standardized and modular design leads to monotonous exteriors and cramped interiors, with户型 (floor plans) lacking human-centered considerations. For example, some units have windowless kitchens or bathrooms and small living rooms.
Renovation Policies and Measures for Prefabricated Panel Houses
Since 2022, China has implemented renovation policies focusing on repair and upgrade, with demolition reserved only for buildings deemed dangerous. Renovations begin with a comprehensive structural safety assessment, emphasizing checks on crack widths in prefabricated panel production areas (requiring special treatment for widths exceeding 0.3 millimeters) and the connection status between panels and ring beams (necessitating bolt replacement if rust rates exceed 30%). During renovations, various reinforcement measures are taken, such as erecting temporary support systems, inserting steel bars, pouring concrete, and adding structural columns, to ensure scientific and safe construction.
