How to Prefabricate Building Components in a Factory

The prefabrication of building components in a factory mainly goes through four stages: design deepening, material processing and component prefabrication, transportation and on-site foundation construction, and assembly and installation.

Design Deepening: Factory technicians carry out structural calculations and node designs based on the building's purpose, site conditions, and customer requirements. This stage is crucial as it needs to ensure that the building's seismic, wind, and moisture resistance performances meet regulatory requirements, providing accurate design references for subsequent component prefabrication.

Material Processing and Component Prefabrication:

• Material Processing: Corresponding processing measures are taken for different materials. Wood needs to undergo drying, anti-corrosion, and insect-proof treatments, such as using the vacuum-pressure impregnation method to allow preservatives to penetrate deep into the wood fibers, extending the lifespan of wooden houses. It also requires surface protective coating treatments, as well as precise cutting and tenoning operations. In a factory environment, quality can be effectively controlled, reducing on-site errors. For the prefabrication of concrete components, it involves processes such as automatic steel bar processing.
• Component Prefabrication:
  • Concrete Components: There are two types: ordinary concrete and prestressed concrete prefabrication, which can be carried out either in a factory or on-site according to the work location. There are various forming methods, such as flat-bed assembly line production and vertical formwork. Vertical formwork can save land, and long-line beds are suitable for open-air production of thin components. Curing is carried out using steam, hot molds, and solar energy. Quality inspection achieves full-process control through QR code traceability and 3D laser scanning technology. Modern technologies include automated equipment such as automatic steel bar processing, CNC concrete distribution robots, and intelligent formwork-setting robots. For example, in the intelligent factory workshop of China Construction Science and Industry Group's steel structure modular products, a house is divided into six faces and produced in parallel on six sub-production lines, and finally assembled into a complete box with a precision control of 1 - 2 millimeters. China Construction HaiLong Intelligent Construction Industrial Park has built the world's first flexible intelligent manufacturing production line for concrete MiC, overcoming industry challenges and achieving efficient production and precise quality inspection.
  • Wooden Structure Components: The factory ensures the dimensional accuracy of components and the reliability of connection nodes through CNC equipment and molds. For example, walls adopt a 'sandwich' structure to improve thermal performance and sound insulation effects; roofs often use lightweight wooden trusses or prefabricated roof panels for convenient and fast on-site installation.

Transportation and On-site Foundation Construction: The prefabricated components are transported to the construction site, and at the same time, on-site foundation pouring work is carried out, such as concrete strip foundations or pile foundations, providing a stable foundation for subsequent component assembly and installation.

Assembly and Installation: Components are assembled on-site. For example, the on-site installation of a general wooden house of about 100 square meters only takes 7 - 10 days, greatly shortening the construction period.