Prefabrication Method of Pentagonal House

There are mainly two prefabrication methods for pentagonal houses: the monolithic casting method and the modular prefabrication and assembly method.

Monolithic Casting Method:
The core of this method lies in "casting in stages". First, the concrete for five sides (such as the base plate and four walls) or four sides (such as four walls plus part of the roof) of a hexagonal house structure is cast as a whole in a factory or on the construction site to form semi-enclosed prefabricated components. After the concrete reaches the designed strength, the remaining one or two components (such as the roof and independent walls) are connected to the prefabricated parts through on-site assembly. The advantage of this method is that it reduces the amount of on-site wet work, but strict control is required over the steel bar anchoring and concrete casting quality at the assembly joints to ensure the structural integrity. For example, if a roof interface is reserved when prefabricating the pentagonal part, on-site assembly requires steel bar binding, formwork erection, and secondary casting for connection, and the vibration compaction process is adopted to avoid cold joints.

Modular Prefabrication and Assembly Method:
This method achieves efficient assembly through standardized design. The specific steps are as follows:

1. Modular Design: The house is decomposed into multiple sets of pentagonal modular boxes (such as standard units with a base plate and four walls), frame columns, and concrete composite beams. The dimensions of the pentagonal modules need to be optimized according to transportation and lifting capabilities, and lightweight high-strength materials (such as high-strength concrete or composite materials) are usually used to reduce the self-weight.
2. Prefabricated Production: The pentagonal boxes, frame columns, and composite beams are prefabricated in batches in a factory. Among them, the composite beams adopt a combination of a prefabricated base plate and on-site casting of the upper part, which not only ensures construction efficiency but also improves structural performance; the frame columns can have steel bar joints reserved for easy connection to the modules.
3. On-site Assembly:
   • After positioning the pentagonal modules according to the design layout, fix the wall connectors of adjacent modules through high-strength bolts or welding;
   • Install concrete composite beams between the modules, ensuring that the prefabricated part at the bottom of the beam is aligned with the reserved steel bars at the top of the modules, and achieve steel bar force transmission through grout sleeves or mechanical connections;
   • Lift the frame columns to the corners of the modules or the designed positions, and form an overall structure through steel bar anchoring and concrete casting.

This method significantly shortens the construction period by reducing on-site wet work and formwork usage, and at the same time, standardized components facilitate quality control. For example, after adopting this technology in a project, the construction period was shortened by 40%, and the assembly error between modules was controlled within 2mm, effectively improving the structural accuracy.