Evaluation of Concrete Prefabricated Houses
The evaluation of concrete prefabricated houses (prefabricated cement houses) reveals advantages such as structural safety, efficient construction, and low cost, but also defects like sound insulation issues and leakage at connection points.
I. Structural Safety Performance
Concrete prefabricated houses adopt a full-frame shear wall design, using Φ10-Φ14 national standard threaded steel bars to construct the framework, combined with C35 concrete for integral pouring. Each module weighs over 20 tons, with wall thicknesses ranging from 150-200mm and floor thickness of 120mm, ensuring strong structural stability. Their seismic resistance can withstand an 8-magnitude earthquake (with a designed seismic fortification intensity of 7 degrees), with wall crack widths controlled within 0.2mm and no damage to the main structure. In terms of wind resistance, under a 12-level typhoon, the prestressed bolt connections between modules remain loose-free, and the roof waterproofing membrane is not at risk of being blown off. The fire resistance rating exceeds 3 hours, superior to the 2 hours of traditional brick-concrete structures.
II. Construction Efficiency and Cost-Effectiveness
During the factory prefabrication stage, a single module (30㎡) takes only 7 days. For on-site installation, a 50-ton crane, assisted by 3 workers, can complete the lifting of a single module in 4 hours, and the entire installation of a 100㎡ house takes only 1 day. Moreover, the modules come with pre-installed water and electricity pipelines, ready for immediate use upon installation. In terms of cost, the main construction cost for a 120㎡ rural self-built house ranges from 120,000 to 150,000 yuan, saving 30% compared to traditional brick-concrete structures. The construction period is shortened to 3 days, and construction waste is reduced by 90%, demonstrating significant comprehensive benefits.
III. Quality Reliability and Defects
Reputable manufacturers use high-strength cement and corrosion-resistant steel bars, enhancing concrete density through steam curing. Node connections employ grout sleeve or bolt anchoring techniques, with construction adhering to the "Technical Standard for Prefabricated Concrete Buildings." However, common defects include leakage at module connection points due to improper gap treatment (15% of prefabricated houses experience this issue); sound insulation performance is 12-15 decibels lower than that of brick-concrete houses, with indoor noise levels reaching 45 decibels; although the theoretical lifespan is 50 years, actual use may see connection part corrosion and micro-cracks appearing after around 10 years.
IV. Practical Application Cases
During the passage of Typhoon摩羯 (Mujigae) in Zhangzhou, Fujian in 2024, a cement house homestay withstood 11-level winds with no damage to its exterior walls or roof. In the 2021 Yangbi earthquake in Yunnan, a prefabricated house project endured a 6.4-magnitude earthquake, with a 98% intact rate of the main structure, verifying its disaster resistance capabilities.
