Prefabricated Panel Hybrid Structure Houses

Prefabricated panel hybrid structure houses are buildings that use prefabricated panels as floor slabs combined with other structural forms (such as brick-concrete structures). They are commonly found in old residential communities built from the 1970s to the 1990s and have defects such as poor integrity and insufficient seismic performance. After 2008, they were gradually replaced by cast-in-place floor slabs, and currently, high-performance composite floor slab technology is mainly applied to new construction projects.

Structural Characteristics and Construction Background

The core feature of prefabricated panel hybrid structure houses is the use of prefabricated hollow floor slabs and brick walls for load-bearing. The prefabricated panels are fixed to the walls through simple overlapping, similar to a "jigsaw puzzle" structure, lacking effective and firm connections. This structural form is mostly seen in old residential communities built from the 1970s to the 1990s and was a technological choice to quickly meet housing demands at that time. The original design intention was to use industrially produced prefabricated panels to improve construction efficiency. However, due to technological limitations, the overall structural integrity and seismic performance were not fully considered.

Structural Defects and Safety Risks

This structure has two major defects: poor integrity and insufficient seismic performance. Since the prefabricated panels are only fixed to the walls through simple overlapping and lack the integral pouring connection of reinforced concrete, under the action of earthquakes or external forces, the prefabricated panels are prone to detachment, and the walls may also collapse due to the loss of support. For example, in the 2008 Wenchuan earthquake, some prefabricated panel hybrid structure houses suffered severe damage due to the falling of floor slabs, exposing the limitations of their seismic performance. In addition, after long-term use, cracks may appear at the connection points between the prefabricated panels and the walls due to material aging, temperature changes, and other factors, further reducing structural safety.

Technological Iteration and Policy Orientation

To improve the safety of building structures, the country gradually phased out prefabricated panels and promoted cast-in-place floor slab technology after 2008. Cast-in-place floor slabs form a stronger integral structure by pouring reinforced concrete on-site, significantly improving seismic performance and durability. Currently, high-performance composite floor slab technology (combining prefabricated panels with cast-in-place layers) has been applied to high-rise buildings and large-span projects (such as the Beijing Changping Life Valley International Biomedical Smart Manufacturing Park and the Quzhou Beihang Digital Economy Industrial Park). However, this technology is mainly aimed at new construction projects rather than the renovation of old prefabricated panel hybrid structure houses. For existing old houses, renovation needs to comprehensively consider factors such as structural reinforcement and cost-effectiveness. Currently, there is no standardized technological solution for large-scale promotion.