Fully Prefabricated Panel House
A fully prefabricated panel house is a type of building constructed primarily using prefabricated panels, which are factory-produced cement components. These panels have issues such as weak earthquake resistance and poor sound and thermal insulation, and are now mostly subject to repair and renovation.
Definition and Types of Prefabricated Panels
Prefabricated panels are cement components produced through standardized factory processes. During production, wooden models are nailed together, reinforced with steel bars, and then filled with cement, resulting in either solid or hollow types. The hollow structure achieves lightweighting by reducing non-load-bearing concrete, lowering material costs and facilitating transportation and installation. These panels have a wide range of applications, including not only the main structure of buildings but also non-load-bearing parts such as highway ditch covers and roof insulation layers.
Historical Background and Development
The construction form of fully prefabricated panel buildings originated in the early 20th century. Due to high industrial production efficiency and low costs, they were widely adopted in residential buildings constructed in China before 1985. The technical limitations of this period restricted structural performance, leading to prevalent design flaws in existing prefabricated panel houses. With advancements in building technology, cast-in-place concrete (with strong overall integrity due to on-site pouring) and prefabricated buildings (with high precision due to modular production) have gradually replaced traditional prefabricated panel structures as the mainstream construction methods.
Existing Issues and Limitations
- Weak Earthquake Resistance: Prefabricated panels are connected by splicing, resulting in joint strength lower than that of cast-in-place structures. They are prone to separation or collapse during earthquakes.
- Poor Sound and Thermal Insulation: The hollow structure or thin-wall design leads to rapid transmission of sound and heat, resulting in low living comfort.
- Limited Service Life: The design life of prefabricated panels is approximately 30-50 years. Long-term use can lead to carbonation of the concrete and rusting of the steel bars, further weakening structural safety.
Policies and Renovation Directions
Since 2022, China has implemented renovation policies that adopt differentiated approaches to prefabricated panel houses:
- Repair and Renovation as the Main Approach: For buildings that do not meet the criteria for dangerous houses, measures such as reinforcing joints, adding insulation layers, and improving sound insulation are taken to extend their service life.
- Demolition of Dangerous Houses: Buildings with severe structural damage that cannot be repaired are demolished and rebuilt according to dangerous house standards to ensure living safety.
Fully prefabricated panel houses are products of a specific historical period, and their limitations have been addressed by modern building technologies. Current policies focus on ensuring safety and improving living quality, achieving rational resource utilization through scientific renovation.
