Prefabricated House Slab Construction

Prefabricated house slab construction refers to the use of prefabricated slabs for house building. These slabs are concrete prefabricated components produced and processed at a prefabrication yard and then transported to the construction site for installation. The following provides a detailed introduction from the aspects of production, types, uses, current status, and comparison with cast-in-place houses:

Production Process

When producing prefabricated slabs, a hollow mold is first made using wooden planks. After placing steel bars in the hollow part of the mold, cement is poured to fill the hollow section. Once the cement dries, the wooden planks are knocked off, leaving behind the prefabricated slab.

Types

Prefabricated slabs come in two types: solid and hollow. The design of the hollow structure achieves lightweighting by reducing the non-load-bearing concrete. While ensuring a certain level of strength, it reduces the weight of the prefabricated slab itself, facilitating transportation and installation.

Uses

Prefabricated slabs have a wide range of uses in the construction field. For example, they can be used on the ditches beside highways as cement slabs to cover the ditches, providing protection and safety. They can also be used on rooftops as cement slabs for thermal insulation layers, helping to regulate indoor temperatures.

Current Status

Nowadays, prefabricated slabs are less commonly used in house construction. Instead, frame structures and reinforced concrete structures are more frequently adopted to improve the safety and quality of buildings. Since 2022, China has been implementing a policy of old housing renovation, focusing on repairing and renovating prefabricated slab houses and only demolishing those that meet the criteria for dangerous buildings. Existing prefabricated slab houses generally have some problems, such as weak earthquake resistance, making it difficult to ensure the safety of occupants during natural disasters like earthquakes; poor sound and thermal insulation, affecting living comfort; and a relatively short service life of about 30 - 50 years.

Comparison with Cast-in-Place Houses

• Construction Method: The construction of a prefabricated slab house is like assembling Lego blocks. The cement slabs are pre-made in the factory and then directly assembled on the construction site, saving time and effort. In contrast, for a cast-in-place house, workers first set up molds and bind steel bars, and then pour concrete and wait for it to solidify.
• Structural Performance: In a cast-in-place house, the beams, columns, and floor slabs form an integral whole, making it extremely sturdy and earthquake-resistant. In comparison, a prefabricated slab house has relatively weaker structural integrity.
• Applicable Scenarios: High-rise residential buildings, large-span spaces, and places like bathrooms usually require cast-in-place construction. If it is a temporary building or the budget is extremely tight, prefabricated slabs can be used, but proper joint waterproofing must be ensured.