Safety of Prefabricated Panels for Building Construction

Prefabricated panels used in building construction have numerous safety hazards and are not safe, as detailed below:

I. Structural Performance Defects

1. Poor Earthquake Resistance: Prefabricated panels have weak integrity, with insufficient steel reinforcement connections between the floor slabs and walls, resembling building blocks. Under seismic horizontal forces, the floor slabs and walls separate instantly and collapse directly, without any crack warnings or deformation buffers, leaving extremely short escape times. In historical earthquakes, buildings with prefabricated panels have had high collapse rates and severe casualties.
2. Vulnerable Connection Points: Prefabricated panels are simply overlapped with walls, with joint filling between panels, lacking rigid frameworks such as ring beams and structural columns. When foundation settlement or wall cracking occurs, the panels are prone to misalignment and loosening; long-term weathering or steel reinforcement corrosion reduces strength, causing some old buildings to have shaky floor slabs after two or three decades of use. Even slight external forces (such as wall demolition or stacking heavy objects) can trigger a chain collapse.
3. Substandard Materials: Non-standard prefabricated panels often use thin steel wires instead of steel reinforcement, with concrete grades that do not meet standards and insufficient thickness, resulting in high brittleness and poor toughness. They may break without warning when overloaded, and sudden collapses can occur due to daily stacking of heavy objects, renovation floor pounding, or long-term aging.

II. Component-Specific Hazards

1. Floor Slab Joint Cracking: The joints at the top of prefabricated panels in self-built houses are prone to cracking, which is one of the fatal hazards.
2. Floor Slab Deformation and Damage: Observe whether there are horizontal through cracks or joint cracks in the ceiling, whether the middle of the floor slab is sinking or bending, and whether the concrete at both ends of the placement is loose, crumbling, or if the steel reinforcement is exposed and rusted.

III. Usage and Renovation Risks

1. Unauthorized Renovations: Unauthorized removal of load-bearing walls, opening doors or windows in load-bearing walls or enlarging openings, adding floors or mezzanines on rooftops, or stacking heavy objects such as large water tanks on floor slabs can all undermine structural stability.
2. Change of Use: When residential buildings are converted into crowded venues (such as restaurants or KTVs), the live load increases significantly, making safety accidents highly likely.

IV. Inspection Points

1. Structural Integrity: Check for foundation settlement (such as ground level differences or diagonal wall cracks), building tilting or distortion.
2. Core Components: Focus on inspecting cracks and deformation in prefabricated floor slabs, cracks and weathering in load-bearing walls, and the firmness of node connections (such as whether the support length is ≥80mm).
3. Usage Environment: Verify whether there are any unauthorized renovations or overloaded usage behaviors.