Prefabricated Concrete Frame House
A prefabricated concrete frame house is a form of prefabricated assembled building, where building components are industrially produced and assembled on-site, with the technology encompassing prefabricated concrete structures.
Development History
China's prefabricated concrete technology originated in the 1950s and was initially used primarily for factory and residential construction. After the 21st century, due to increased production efficiency and environmental protection needs, the technology regained attention. Companies like Vanke Group developed prefabricated shear wall residential structural systems and applied prefabricated frame technology in projects, such as the Nanjing Jindi Yufang project, which adopted a prestressed prefabricated concrete assembled integral frame structural system.
Connection Types and Seismic Performance
The NEHRP 2000 code in the United States classifies prefabricated concrete frame connections into two categories:
- Equivalent Cast-in-Place Connections: These are required to have seismic performance that meets or exceeds that of cast-in-place concrete connections. Common joint forms include post-cast monolithic and prestressed spliced types. Among them, unbonded prestressed tendon spliced joints exhibit minimal strength and stiffness degradation after large deformations, with low residual deformation and strong recovery capabilities. The clamping restraint effect of prestressing also enhances the shear performance of the joint area and reduces the amount of stirrups required.
- Assembled Connections: These have different mechanical properties from cast-in-place concrete connections, and the NEHRP code has separate provisions for their seismic design. Common joint forms include welded joints and bolted connections.
Application Status and Challenges
Although prefabricated concrete frame houses offer advantages such as industrial production and high construction efficiency, research on their seismic performance in China still lags behind advanced international levels. Due to insufficient understanding of structural seismic mechanisms, related engineering applications are restricted in earthquake-prone areas. Further experimental and theoretical research is needed to improve design methods and enhance seismic reliability.
Technological Advantages
Prefabricated concrete frame houses significantly improve construction quality, shorten construction periods, and reduce on-site wet operations through factory-standardized component production, aligning with green building trends. Innovative technologies such as unbonded prestressed tendon spliced joints provide new ideas for enhancing structural ductility and seismic performance, but they need to be optimized based on China's codes and engineering practices.
