House with Prefabricated Slabs and Brick-Concrete Structure
Houses with brick-concrete structures may use prefabricated slabs, but these are two different concepts, and the use of prefabricated slabs in brick-concrete structures requires careful consideration of seismic performance.
Brick-concrete structures are hybrid structural systems where load-bearing is shared by brick walls and reinforced concrete beams, slabs, and other components. The vertical load-bearing components are constructed using bricks or blocks, while the horizontal components are made of reinforced concrete. This type of structure offers advantages such as simple construction, low cost, good durability, and fire resistance. However, it has drawbacks including significant self-weight, relatively weak seismic performance, and a typical height limit of six stories or less.
Prefabricated slabs are floor slabs manufactured in advance at a factory and directly installed on-site, offering fast construction speeds and lower costs. However, their seismic performance is relatively poor. Houses built before 2003 more commonly used prefabricated slabs, after which cast-in-place concrete slabs gradually became the mainstream due to their superior integrity and seismic performance. Experimental data shows that cast-in-place slabs can withstand an 8-degree earthquake, while prefabricated slabs can only withstand a 6-degree earthquake; under the same seismic force, the seismic performance of cast-in-place slabs is 2 to 3 times that of prefabricated slabs. For example, in a certain earthquake, 80% of houses with prefabricated slabs collapsed, while less than 5% of houses with cast-in-place structures collapsed.
Houses with brick-concrete structures do not necessarily use prefabricated slabs; their floor slabs can be either prefabricated or cast-in-place concrete slabs. If prefabricated slabs are used, special attention must be paid to seismic fortification requirements. Prefabricated slabs are not suitable for seismic fortification zones, and it is recommended to prioritize cast-in-place floor slabs to improve the overall integrity and seismic performance of the house. For long-term residential houses, especially those with three stories or less, it is recommended to adopt a brick-concrete structure and install ring beams and structural columns to enhance structural stability. When purchasing a second-hand house, special attention should be paid to the fact that brick-concrete houses built before 2003 may have used prefabricated slabs, which have relatively poor seismic performance, and the safety of the house should be carefully evaluated.
