Sudden Fall of Prefabricated House Slab
The sudden fall of prefabricated house slabs can cause serious casualties and property damage, with the main causes including excessive load and house aging.
Excessive load as a common cause: Taking the house collapse incident in Fengshou Community, Guanba Town, Zhong County, Chongqing, at around 12:00 on April 11, 2024, as an example, the accident was caused by an excessive temporary load on the second-floor slab, exceeding the load-bearing capacity of the prefabricated slab, resulting in brittle fracture and fall of the slab. Prefabricated slabs are designed with certain load-bearing standards. When the actual weight they bear, such as the concentrated stacking of a large amount of building materials, furniture, or excessive gathering of people, exceeds their designed load-bearing capacity, it may trigger fracture and fall. This sudden increase in load causes a sharp rise in the internal stress of the prefabricated slab. When the stress exceeds the ultimate strength of the material, brittle failure occurs, that is, sudden fracture without obvious warning.
House aging increases risks: Prefabricated houses have drawbacks such as a short service life and poor seismic performance. As time goes by, old prefabricated houses pose significant safety hazards. During long-term use, prefabricated slabs are affected by the natural environment, such as rain erosion and temperature changes, leading to concrete carbonation and steel bar corrosion. Concrete carbonation reduces its alkaline environment, causing the steel bars to lose protection and accelerating corrosion. After steel bar corrosion, the volume expands, causing concrete cracks and further weakening the structural performance of the prefabricated slab. At the same time, during the use of the house, factors such as foundation settlement and structural deformation may cause the connections between prefabricated slabs to loosen, reducing the overall structural stability and increasing the risk of fall.
Other potential factors: In addition to the above main causes, construction quality issues may also lead to the fall of prefabricated slabs. If the connections are not firm or the support structure is unreasonable during the installation of prefabricated slabs, it will affect their stability. In addition, natural disasters such as earthquakes can also cause severe damage to prefabricated houses, triggering the fall of prefabricated slabs.
