Prefabricated Brick-Concrete Structure House

Prefabricated brick-concrete structure houses typically refer to those built from the 1970s to the 1990s, featuring a brick-concrete structure combined with prefabricated hollow floor slabs. From the perspective of modern building safety standards, these houses have inherent weaknesses such as poor integrity and inadequate earthquake resistance.

From a construction perspective, the prefabricated slabs are simply placed on the walls like puzzle pieces, lacking a firm connection between them. When an earthquake occurs, the problems with this structure become apparent. Stairwells are prone to becoming weak points, with prefabricated slabs easily falling and stairwell walls collapsing. This is because there is no effective overall connection between the prefabricated slabs and the walls, preventing them from jointly resisting seismic forces. When seismic waves arrive, the connection points between the walls and the prefabricated slabs are prone to loosening and breaking, leading to the falling of the slabs, which can injure people or damage indoor facilities. At the same time, the stairwell walls lose support and collapse, obstructing evacuation.

The quality of prefabricated brick-concrete structure houses built in different eras varies. Houses built around 1978 generally have no earthquake resistance measures, lacking both structural columns and ring beams. The strength of the mortar and bricks is low, resulting in poor overall integrity and seismic performance. Structural columns and ring beams play a crucial role in enhancing the overall integrity and stability of building structures. Houses lacking these elements are highly vulnerable to external forces such as earthquakes, resembling a body without a skeleton and prone to collapse. Houses built around 1984 still have low design standards, with inadequate consideration for earthquake resistance, and continue to use prefabricated slab structures, resulting in poor overall integrity. Although time has progressed, there has been no substantial improvement in construction techniques and concepts, leaving the seismic resistance of these houses still weak. Houses built around 1995 began to incorporate preliminary earthquake-resistant designs, with structural columns installed and ring beams set up every other floor. However, they still essentially remain prefabricated slab brick-concrete structures, with limited quality improvement. Although the installation of structural columns and ring beams adds some overall integrity and stability to the houses, the structural characteristics of the prefabricated slabs still limit further enhancement of their seismic resistance.

After 2008, the country urgently revised building seismic codes, comprehensively strengthening structural columns and ring beams in stairwells, and gradually phasing out prefabricated slabs in favor of cast-in-place floor slabs to improve the seismic performance and overall safety of houses.