Are Prefabricated Floor Slabs for Houses Safe?
Prefabricated floor slabs for houses are unsafe and pose multiple hazards.
Extremely Weak Earthquake Resistance: Prefabricated slabs have poor integrity, resembling building blocks, and are not firmly connected to the walls. During an earthquake, the floor slabs and walls can easily separate instantly and collapse suddenly without any warning cracks or deformation buffer time. In many historical earthquakes, prefabricated slab houses have suffered severe collapses, resulting in a large number of casualties, with their earthquake resistance being almost zero.
Vulnerable Connection Points: There is usually only simple overlapping between prefabricated slabs and walls, and simple joint filling between slabs, lacking rigid frame structures such as ring beams and structural columns. When the foundation settles or the walls crack, the prefabricated slabs are prone to misalignment and loosening. Over time, the connection points will weather, the steel bars will rust, and the strength will decrease, potentially triggering a chain collapse.
Numerous Material Issues: Regular prefabricated slabs have relatively thin steel bars, while those produced by some small workshops often use thin steel wires instead of steel bars. The concrete grades are substandard and the thickness is insufficient, making the prefabricated slabs brittle and prone to fracture. When exceeding their load-bearing capacity, they can break instantly without any warning.
Poor Structural Strength: Prefabricated slabs are assembled by splicing and adopt a hollow design, with a steel bar density much lower than that of cast-in-place structures. When encountering natural disasters such as earthquakes and strong winds, their earthquake resistance is poor, and serious cracks may appear. Structural fatigue caused by micro-earthquakes will continuously expand the cracks, increasing the risk of collapse.
Cracks and Water Leakage: Cracks frequently occur in prefabricated slab houses, which not only weaken the overall strength of the walls and increase the probability of collapse but also create a damp environment due to water leakage, which is prone to breeding mold and bacteria, endangering the health of the occupants.
Poor Thermal Insulation and Sound Insulation: Prefabricated slab houses lack good thermal insulation materials. In summer, the indoor environment is stuffy, and it is difficult for air conditioners to cool the space; in winter, it is cold, and it is difficult for heating systems to warm the space, also increasing energy consumption costs. At the same time, their sound insulation effect is poor, affecting living comfort and health.
Limited Service Life: The 'lifespan' of prefabricated slab houses is generally only 30 to 40 years. As time goes by, their safety hazards will gradually increase.
