Prefabricated Concrete House Construction

Prefabricated concrete houses, also known as prefabricated concrete buildings, are a form of construction where concrete components are cast in a factory in advance and then transported to the site for assembly.

Construction Process

1. Factory Prefabrication: Workers assemble metal steel plates into molds using bolt connectors. After applying a release agent, they place steel bars in a crisscross pattern and bind them into a mesh framework with steel wires. Connectors are placed symmetrically inside the steel bar mesh, followed by filling with concrete. During pouring, vibrators are used to remove air bubbles. After the surface is smoothed, plastic sheds are covered and heating devices are installed to ensure and promote the hydration reaction of the cement.
2. On-site Assembly: First, the foundation is laid. A pit about 1 meter deep is dug on the building site. After laying a moisture-proof PE film at the bottom of the pit, "discarded concrete" is poured into the pit as a base. Once this layer of discarded concrete, which is more than 10 cm thick, has completely solidified, guide steel plates for positioning the prefabricated concrete piles are installed. Finally, the large prefabricated concrete base plate is placed on the guide steel plates.

Advantages and Characteristics

1. Fast Construction Speed: The production cycle for a single module is only 7 days, with an error margin controlled within 2 millimeters. During on-site hoisting, a 50-ton crane, in conjunction with an intelligent positioning system, can complete the installation of the main structure of a single villa in 4 hours. A 100㎡ house can be ready for occupancy in just 5 days from a bare site. The construction period for a 300㎡ house is 180 times more efficient compared to traditional construction methods.
2. Lower Cost: The labor cost for a 100㎡ house is reduced by 60% compared to traditional construction methods.
3. Better Quality: A full-frame shear wall structure is adopted, using C35 concrete and Φ14 threaded steel bars. The reinforcement ratio of a single module reaches 1.2%, with a wall thickness of 200mm and a compressive strength of 30MPa, equivalent to being able to withstand a weight of 3000 tons per square meter. Modules are connected using prestressed bolts (with a tensile strength of 25 tons) combined with traditional Chinese architectural mortise-and-tenon joints. In a simulated Wenchuan earthquake test, the overall displacement was only 3cm under a 9-degree intensity shake. The walls are embedded with EPS insulation layers, and the roof is reserved with interfaces for photovoltaic panels. A 200㎡ house can generate up to 3000 degrees of electricity annually.
4. Good Environmental Performance: Construction waste is reduced by 98% compared to traditional construction methods. For example, in Fujian Province and other regions, through policy support, industrial bases have been established, achieving a reduction in construction waste of more than 70%.

Development History

Prefabricated concrete technology in China began in the 1950s and was initially applied to factory and residential construction. In the 1970s, driven by the policy of "industrialization, standardization, and mechanization" in construction, technical systems such as large-panel structures and box structures were formed. In the mid-1980s, it stagnated due to cost and quality defects but has since revived in the 21st century due to its production efficiency and environmental advantages.