How to Make Prefabricated Panel Houses

Prefabricated panel houses are constructed using prefabricated panels as the main components, through a process of fabrication and installation. The fabrication process is as follows:

Fabricating Prefabricated Panels

1. Preparing the Molds: Workers first position and secure the side steel molds at predetermined locations. Then, they lift the transverse steel molds together and tighten all the surrounding nuts using a pneumatic wrench to fix the molds in place.
2. Applying Release Agents: A release agent is evenly sprayed onto the fixed molds to prevent the subsequently poured concrete from adhering to the molds, facilitating the mold removal process.
3. Installing Reinforcement Bars:
   • Distribution bars are brought in, which form a stirrup structure with steel bars, primarily serving to enhance the crack resistance and overall compressive strength of the concrete.
   • Steel strands (load-bearing bars) are lifted and threaded through one end of the mold to the other, combining the load-bearing bars with the distribution bars to strengthen the prefabricated components. Anchoring fixtures are also installed at this stage.
4. Installing Pouring Steel Molds: Pouring steel molds are placed to create a hollow effect, which will be removed during mold removal later.
5. Prestressing the Reinforcement Bars:
   • When using the pre-tensioning method, a machine similar to a hydraulic cylinder is used to stretch the load-bearing bars, making the internal steel strands straighter. There is also the post-tensioning method, where concrete is poured first, followed by the stretching of the reinforcement bars. The procedures differ, but the essence remains the same.
   • To keep the reinforcement bars centered, small plastic blocks are installed at the bottom.
6. Pouring Concrete: The control room automatically processes gravel and water to prepare the concrete, which is then poured into the molds. The bottom layer of concrete is poured first (as a base). In some fabrications, a four-centimeter-thick layer of cement is laid first, followed by the placement of a 15-centimeter-thick giant foam block, which is fixed at the connections with an iron hook. Some consider this a lightweight design with sound insulation effects, while others view it as shoddy workmanship.
7. Subsequent Processing:
   • Workers use vibrating rods to vibrate back and forth, expelling air bubbles from the concrete to prevent cracking due to excessive air bubbles.
   • The entire panel is lifted and sent to an underground basement "sauna" for four hours of high-temperature steam curing to harden it quickly. Alternatively, a gentle approach can be taken by directly covering it with a waterproof membrane for one day of natural curing.
   • Precision cutting is performed using a CNC electric saw. The hollow design of the prefabricated panels can be used for routing cables and draining sewage.

Constructing the House

The fabricated prefabricated panels (available in solid and hollow types, with the hollow structure achieving lightweighting by reducing non-load-bearing concrete) are transported to the construction site and directly installed to form the house.