Pre-fabricated Panel House (Note: 'Zhu Dou Cao' is not a standard term related to pre-fabricated panel houses)

'Zhu Dou Cao' is not a standard term related to pre-fabricated panel houses. The following is a detailed introduction to pre-fabricated panel houses:

Pre-fabricated panel houses are structures built primarily using pre-fabricated panels. These panels are cement components manufactured in factories. During production, a wooden mold is first nailed together, followed by the placement of steel reinforcement and the pouring of cement, resulting in both solid and hollow types. The hollow structure achieves lightweighting by reducing the non-load-bearing concrete portion.

Advantages:

• Low Cost: Pre-fabricated cement panels are relatively inexpensive, and construction is fast. In rural self-built housing scenarios, hoisting can be completed in a day or half a day, effectively reducing construction and time costs.
• Convenient Construction: Components are pre-fabricated in factories, and only assembly is required on-site, significantly shortening the construction period and reducing the complexity and uncertainty of on-site construction.

Disadvantages:

• Waterproofing Issues: There is a high probability of water leakage during waterproofing, with data showing that 8 out of 10 houses experience leaks. The waterproofing industry also finds it difficult to guarantee 100% leak-proofing.
• Poor Earthquake Resistance: They cannot be used in earthquake-prone areas due to their low seismic resistance coefficient, which can easily lead to collapse. Post-earthquake surveys in Wenchuan revealed that a significant proportion of collapsed rural self-built houses used pre-fabricated panel structures.
• Poor Thermal Insulation: The floor slab is typically about 12 centimeters thick, and despite being hollow, its thermal insulation is poor. Summer temperatures inside are high, and winter temperatures are low, often requiring secondary roofing material coverage on the floor slab for improvement.
• Poor Integrity: Panels are simply placed on load-bearing walls without effective connections, resulting in poor overall integrity. Slight violent shaking can cause displacement or even detachment.
• Poor Sound Insulation: Gaps and connection points between pre-fabricated panels create sound bridges, allowing easy transmission of noise between floors and neighboring units. Sound insulation is 15 - 25 decibels lower than current standards.
• Limited Service Life: The service life of existing pre-fabricated panel houses is approximately 30 - 50 years.

Since 2022, China has implemented renovation policies for pre-fabricated panel houses, focusing on repair and renovation, and only demolishing buildings that meet the criteria for dangerous houses. For unstable old pre-fabricated panel houses, methods such as pouring a layer of reinforced concrete 'composite layer' on top of the pre-fabricated panels and adding 'reinforced concrete夹板 walls' (double-skin walls with concrete) on the inner and outer sides of the walls can be used for reinforcement.