How is Prefabricated Housing Made

There are two common methods for prefabricated housing: modular construction and prefabricated panel production, both of which involve rigorous and scientific manufacturing processes.

Modular Construction

Modular construction involves breaking down a building into individual modules, which are manufactured in a factory and then transported to the construction site for assembly. Specifically, elements such as ceilings, walls, and bathroom waterproofing layers are prefabricated on factory assembly lines. This process is similar to the automotive industry, where individual components are first produced separately. For example, ceiling and wall components are manufactured at their respective stations, while bathroom waterproofing layers are produced in a dedicated area according to specific processes. Afterward, these individual components are sent to the final assembly station for complete assembly, forming independent building modules. These modules possess complete functions and structures and undergo strict quality inspections in the factory to ensure compliance with building standards. Finally, the prefabricated modules are transported to the construction site and precisely assembled using professional lifting equipment to quickly construct a complete building. The advantages of modular construction include high production efficiency, controllable quality, reduced wet work on the construction site, and lower environmental impact.

Prefabricated Panel Production (Taking 'Foam Sandwich Panels' as an Example)

1. Mold Preparation: Workers first form a large mold by surrounding steel plates and tighten the screws before spraying a release agent to prevent subsequent concrete from adhering to the mold, which could affect the demolding and quality of the prefabricated panels.
2. Reinforcement Cage Placement: The first layer of reinforcement cage (distribution bars) is placed, and its dimensions must be precise to ensure the structural strength and stability of the prefabricated panels.
3. Concrete and Foam Board Placement: After laying approximately four centimeters of concrete, a massive foam board with a thickness of 15 centimeters is placed. The foam pieces are connected with iron hooks to fix their shape and prevent displacement during subsequent operations.
4. Additional Reinforcement Cage Placement: Another layer of reinforcement cage is laid on the foam board, and several strands of high-tensile-strength steel strands (load-bearing bars) are threaded through to enhance the load-bearing capacity of the prefabricated panels.
5. Steel Strand Tensioning and Concrete Pouring: Special equipment is used to tension each steel strand to its ultimate strength (pre-tensioning method), followed by pouring a second layer of concrete to tightly bond the steel strands with the concrete, enabling them to jointly bear the load.
6. Vibration and Curing: A vibrating rod is used to vibrate and expel air bubbles to prevent cracking. Afterward, the panels are sent to a basement for up to four hours of steam curing to accelerate concrete hardening and strength development.
7. Demolding and Finishing: After curing and when the concrete has hardened, the steel strands are loosened, and the panels are lifted out using a gantry crane by hooking onto the four corners. A prefabricated panel is thus born. An angle grinder is then used to cut off the excess steel bars at both ends to meet design requirements.