Brick and Prefabricated Structure House

A brick and prefabricated structure house is a hybrid structural system where load-bearing components such as brick walls and prefabricated hollow floor slabs work together. It has drawbacks such as poor integrity and weak seismic performance, but its performance can be improved by adding structural columns and ring beams.

Structural Characteristics and Historical Background
In brick and prefabricated structure houses, vertical load-bearing components are constructed using bricks or masonry blocks, while horizontal components are prefabricated hollow floor slabs. These components are simply connected to form a load-bearing system. This type of structure was widely used from the 1970s to the 1990s due to its convenient construction and relatively low cost, effectively meeting the housing demands of the time. However, its design concept was based on early building standards and did not fully consider modern seismic requirements, resulting in inherent deficiencies.

Core Defects and Risks

1. Poor Integrity: The connection between the prefabricated slabs and the walls is simple and lacks effective anchoring, resembling a jigsaw puzzle connection, which leads to insufficient structural integrity. Under seismic or external forces, the prefabricated slabs are prone to sliding and detachment, and the walls are likely to crack or even collapse.
2. Weak Seismic Performance: During the 1976 Tangshan Earthquake, such houses suffered severe damage, with stairwells becoming weak points. The falling of prefabricated slabs and the collapse of walls were the main forms of seismic damage. After 2008, the national seismic code was revised, gradually phasing out prefabricated slabs and promoting cast-in-place floor slabs to enhance seismic capacity.
3. Other Drawbacks: The heavy self-weight increases the load on the foundation. Construction requires a large amount of wet work and manual handling, resulting in low efficiency. When renovating old houses (such as adding elevators), chiseling walls and removing beams may damage the overall structural integrity and pose fire safety risks.

Improvement Measures and Applicability
Adding structural columns and ring beams can significantly improve the integrity and seismic performance of brick and prefabricated structure houses. Structural columns enhance the connection between the walls and the floor slabs, while ring beams constrain wall deformation, forming a "frame-constraint" system. However, it should be noted that such renovations require professional institutions to assess the structural safety to avoid secondary damage caused by improper construction. For old residential areas, a comprehensive inspection of the house condition should be conducted before renovation, prioritizing plans that have minimal impact on the structure and ensuring compatibility between the old and new structures.