Prefabricated Panels in Rural House Structures

The prefabricated panels used in rural house structures are factory-made cement components that have issues with connection, leakage, sound insulation, and earthquake resistance. They are gradually being replaced, have specific common sizes, and the renovation policy for old houses focuses on repair and renovation.

Basic Information about Prefabricated Panels
Prefabricated panels are cement components made in factories. During production, a wooden mold is first nailed together, then steel bars are arranged and cement is poured to form the panel. They come in two types: solid and hollow. The hollow structure reduces the amount of non-load-bearing concrete, achieving lightweighting for easier transportation and installation.

Problems with Prefabricated Panels

• Poor Connection and Structural Integrity: The ends of prefabricated panels rest on walls. Even with the pouring of a ring beam, their overall structural integrity is still much weaker than that of cast-in-place floor slabs. Cast-in-place floor slabs are poured simultaneously with the ring beam, forming a continuous structure, while gaps exist between prefabricated panels, which can lead to uneven structural loading.
• High Risk of Cracking and Leakage: The gaps at the joints of prefabricated panels are prone to leakage, especially in water-using areas such as kitchens and bathrooms, where the probability of leakage is significantly higher than that of cast-in-place slabs. Over time, these gaps may further widen due to settlement or material aging.
• Inadequate Sound Insulation: Prefabricated panels are typically 12-15 centimeters thick and have either a solid or hollow internal structure, which provides limited sound insulation. Footsteps and the movement of objects from the floor above can easily be heard below, affecting living comfort.
• Weak Earthquake Resistance: The connection between prefabricated panels and walls relies on local anchoring. During an earthquake, the panels are prone to detachment or overall collapse due to connection failure. Cast-in-place structures have significantly better earthquake resistance due to their overall structural integrity.
• Limited Service Life: The designed service life of prefabricated panels is approximately 30-50 years. In actual use, they may be damaged prematurely due to environmental corrosion, overloading, and other factors, requiring regular inspection and repair or replacement.

Common Sizes of Prefabricated Panels
The length is generally 3-4.2 meters, increasing in increments of 30 centimeters. Transportation becomes difficult for lengths exceeding 4.2 meters. The width options are 50 centimeters and 60 centimeters. For thickness, 12 centimeters is sufficient for ordinary rooms, while rooms on the second floor or those requiring load-bearing capacity need a thickness of 15 centimeters or more.

Policy and Replacement Trends
With advancements in construction technology, cast-in-place concrete and prefabricated buildings are gradually replacing prefabricated panels due to their advantages in structural integrity and earthquake resistance. Since 2022, China has implemented a renovation policy for old houses, focusing on repair and renovation of prefabricated panel houses and only demolishing buildings that meet the criteria for dangerous houses. Some regions have already initiated demolition work.