Cast Concrete Prefabricated Housing

Cast concrete prefabricated housing is a form of construction that involves industrial production of building components and on-site assembly, also known as prefabricated modular construction. Its construction process can be divided into two core stages: component production and on-site assembly, offering advantages such as shortened construction periods and reduced pollution.

Component Production Stage:
In the factory, metal molds are first assembled, with metal steel plates connected by bolts to form a casting cavity. The mold surface is coated with a release agent to facilitate subsequent demolding. Next, steel bars are cross-tied into a mesh framework to enhance the tensile strength of the concrete, and connectors are symmetrically arranged inside the framework to serve as lifting interfaces for the components and cranes. Concrete filling is carried out by direct pouring from a mixer truck, accompanied by high-frequency vibration from a vibrator to eliminate air bubbles and ensure structural density. After pouring, the surface is smoothed, covered with a plastic greenhouse, and an internal heating device is activated. By controlling the temperature (usually 20-30°C) and humidity (>90%), the cement hydration reaction is accelerated, shortening the curing period to 24-48 hours and ultimately yielding components with a strength exceeding 70% of the design value.

On-site Assembly Stage:
For foundation construction, a 1-meter-deep pit is excavated, and a PE damp-proof membrane is laid at the bottom before pouring more than 10 cm of waste concrete as a base, utilizing its low cost and good compactness to form a stable foundation. After solidification, guide steel plates are installed to position the prefabricated piles, and a laser level is used to calibrate the verticality error to ≤3 mm. For large-scale floor slab lifting, a two-point lifting method is employed to ensure a horizontal deviation of the component of <5 mm. Walls, floor slabs, and other components are connected through pre-embedded bolts and sleeves, with high-strength grout injected at the joints to achieve structural integrity. The assembly period for a single floor can be compressed to 3-5 days.

Technological Advantages and Development:
This technology originated in the 1950s and was initially applied in factory construction. It experienced a resurgence in the 21st century due to environmental protection demands. The prefabricated shear wall system developed by companies like Vanke achieves a component reuse rate of over 85% through standardized design, combined with BIM technology to control errors to <2 mm. On-site construction noise is reduced by 40%, dust emissions by 60%, and the construction period is shortened by 30%-50% compared to traditional methods, aligning with the trend of green building development.