Prefabricated Cement House Exterior Wall

The exterior walls of prefabricated cement houses are mainly composed of prefabricated cement panel walls, which have specific material processes, specifications, types, advantages, and disadvantages.

Materials and Processes: Some exterior walls of prefabricated cement houses use prefabricated cement panel walls, with Portland cement and steel reinforcement bars as the main materials, pre-molded into panel shapes using templates. Others adopt a standardized factory production process, starting from binding steel bars, assembling templates, pouring concrete, steam curing, to demolding and hoisting the next day. The entire process is completed within the factory, and only assembly construction is required on-site.

Specifications and Types: Prefabricated cement panel walls are divided into solid and hollow types, with hollow prefabricated panels reducing weight and cost. In terms of standard specifications, the maximum span is 4.2 meters, with widths commonly at 500mm or 600mm, and thicknesses mainly at 120mm and 150mm. There are also cases where the wall thickness is uniformly controlled at 15 centimeters.

Advantages:

• Low cost and convenience: In rural areas, prefabricated cement panels are low-cost and convenient, suitable for building enclosing walls with fast construction speeds.
• Simple and fast construction: Prefabricated in the factory and hoisted on-site. After being transported to the construction site, 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, and a 100㎡ house can be ready for occupancy in just 5 days from an empty lot.
• Good performance: Adopting a full-frame shear wall structure with C35 concrete and Φ14 threaded steel bars, the single-module reinforcement ratio reaches 1.2%, with a wall thickness of 200mm and a compressive strength of 30MPa, equivalent to withstanding 3000 tons per square meter. The double connection of mortise-and-tenon and bolts combines pre-stressed bolts (with a tensile strength of 25 tons) with the mortise-and-tenon structure of ancient buildings. In the Wenchuan earthquake simulation test, the overall displacement was only 3cm under a 9-degree intensity shake. The wall is embedded with an EPS insulation layer (with a thermal conductivity of 0.03W/(m・K)), saving 50% on heating costs in winter. The roof is reserved with photovoltaic panel interfaces, and a 200㎡ house can generate up to 3000 kWh of electricity annually, meeting household electricity needs. In the actual typhoon test in Yangjiang, Guangdong, the prefabricated cement house withstood a Category 12 typhoon (wind speed of 37m/s), while the tiles of adjacent traditional brick houses flew away, and its exterior wall tiles did not fall off, with window and door deformation less than 1mm.

Disadvantages: Prefabricated cement panel walls have problems such as poor thermal insulation performance, insufficient structural stability, weak load-bearing capacity, and cracking and leakage caused by gaps between panels. They have been banned in the construction field, but prefabricated concrete wall panels, as one of the prefabricated building components, are still used in some projects.