Prefabricated Panel House Structure

Prefabricated panel houses are structures built primarily using prefabricated panels, with their characteristics, history, existing issues, and renovation policies outlined as follows:

1. Structure and Manufacturing Process

Prefabricated panels are cement components manufactured in factories. During production, wooden molds are nailed together, steel reinforcement is laid out, and cement is poured to form the panels, which come in solid and hollow types. The hollow structure reduces the amount of non-load-bearing concrete, achieving lightweight construction that lowers material costs and facilitates transportation and installation. These components are highly standardized, offering superior construction efficiency compared to traditional cast-in-place methods, although the strength of joint connections is limited by the quality of on-site assembly.

2. Historical Background and Applications

This building form originated in the early 20th century and rapidly spread due to the advantages of industrialized production. In China, most residential buildings constructed before 1985 used prefabricated panel structures, particularly during the planned economy era when their rapid construction capabilities met the demand for large-scale housing. However, limited by the technical standards of the time, early prefabricated panel houses had deficiencies in steel reinforcement configuration, concrete strength, and joint design, posing risks for subsequent use.

3. Existing Issues and Limitations

• Weak Earthquake Resistance: The connections between prefabricated panels are mostly rigid splices, lacking overall integrity, making them prone to structural disintegration due to joint failure during earthquakes.
• Poor Sound and Thermal Insulation: Hollow or single-layer solid panels have limited thickness, and the high thermal conductivity of concrete results in poor indoor temperature and humidity regulation.
• Limited Service Life: The design life is typically 30-50 years, with increased risks of concrete carbonation and steel reinforcement corrosion after extended use.
• Difficult Renovation: Walls are mostly load-bearing structures, limiting spatial layout adjustments, and pipeline systems are embedded within the panels, leading to high maintenance costs.

4. Alternative Technologies and Renovation Policies

With advancements in building technology, cast-in-place concrete (with strong overall integrity) and prefabricated buildings (such as CMC composite modules, which enhance earthquake resistance through steel-concrete integrated pouring and reduce construction time by 30%) have gradually become mainstream. Since 2022, China has implemented renovation policies for prefabricated panel houses, adopting differentiated approaches:

• Renovation and Upgrading: For structurally safe but functionally outdated houses, performance is improved through joint reinforcement, addition of thermal insulation layers, and pipeline updates.
• Demolition and Reconstruction: Only for buildings identified as dangerous (e.g., with severe cracks, tilting, or joint failure) to ensure resident safety.

The rise and fall of prefabricated panel houses reflect the transition in building technology from "rapid construction" to "safety and durability," with renovations needing to balance historical value preservation with modern living requirements.