Concrete Application in Prefabricated Houses
The application of concrete in prefabricated houses primarily occurs during the factory prefabrication stage, rather than directly "pouring concrete" on the construction site, where assembly and a small amount of connection are the main tasks. The specific processes are as follows:
Factory-Prefabricated Concrete Components
Prefabricated houses utilize prefabricated concrete technology, with the core process being the pre-production of concrete components in factories or on-site. These components include structural elements such as beams, slabs, walls, and columns, which are produced using standardized processes such as the bench method, assembly line method, or conveyor belt method. For example, the bench method involves casting components on a fixed bench, the assembly line method improves efficiency through multi-station collaborative operations, and the conveyor belt method enables continuous production using a conveyor belt. Some components also incorporate fiber reinforcement technology, enhancing properties such as crack resistance and impact resistance by adding steel or synthetic fibers to meet special design requirements.
On-Site Assembly Operations
After being transported to the construction site by vehicles, the prefabricated concrete components need to be precisely installed at their designated positions using lifting equipment such as tower cranes or truck cranes. Taking modular construction as an example, the house is disassembled into independent modules, with each module completing processes such as concrete pouring, pipeline embedding, and decoration in the factory. On-site, only bolt connections or welding are required to fix the module interfaces, enabling rapid assembly. This model of "full-process factory production + rapid on-site assembly" significantly shortens the construction period and reduces the amount of on-site wet work.
Cast-in-Place Connections (for Some Projects)
In a minority of prefabricated house projects, to enhance overall structural stability, cast-in-place concrete connections are made between prefabricated modules. For instance, a public housing project in Shenzhen, Guangdong Province, adopts prefabricated modular technology but uses cast-in-place concrete to fill vertical and horizontal joints between modules, forming a continuous load-bearing system. However, such cast-in-place operations are limited to local key nodes, with a much smaller volume compared to traditional cast-in-place construction. Additionally, high-strength grouting materials or self-compacting concrete are required to ensure connection quality.
Differences from Traditional Cast-in-Place Construction: Traditional cast-in-place concrete requires formwork installation, steel bar tying, concrete pouring, and curing on the construction site. In contrast, prefabricated houses transfer most concrete operations to the factory, ensuring component quality through standardized production. On-site, only assembly and a small amount of connection are required, offering advantages such as high construction efficiency, controllable quality, and minimal environmental impact.
