Quality Standards for Customization of Prefabricated Houses
The quality standards for customization of prefabricated houses cover five core aspects: building materials, structural design, physical properties, construction techniques, and acceptance criteria, as detailed below:
Building Material Standards form the foundation of quality. Cement must comply with the requirements of GB 175-2007 'General Portland Cement' to ensure strength and stability. Reinforcing steel bars should meet the provisions of GB/T 1499.2-2018 'Steel for the Reinforcement of Concrete - Part 2: Hot-Rolled Ribbed Bars' to guarantee structural load-bearing capacity. Aggregates must be selected according to GB/T 14684-2011 'Sand for Building' and GB/T 14685-2011 'Pebble and Crushed Stone for Building', controlling silt content and particle size distribution to avoid affecting concrete performance.
Structural Design Standards must balance safety and functionality. Adhering to GB 50010-2010 'Code for Design of Concrete Structures' and GB 50009-2012 'Load Code for the Design of Building Structures', they specify requirements for the load-bearing capacity, seismic performance, and durability of prefabricated components. For example, the designed live load for residential prefabricated floor slabs should be no less than 200 kilograms per square meter, with the dead load including the self-weight of the slab and the weight of the finishing layer. Ordinary prefabricated slabs are suitable for spans of 3-6 meters; exceeding this requires special calculations and structural reinforcement. The resting length of prefabricated components should be no less than 10 centimeters to ensure effective connection at supports. Seismic codes require prefabricated structures to pass integrity checks, with energy-dissipating devices or redundant restraint systems installed at joint connections to withstand repeated seismic loads.
Physical Property Standards focus on living experience and durability. In terms of sound insulation, the airborne sound insulation level of separating walls should be no less than 50 decibels, and the impact sound pressure level of floor slabs should be controlled below 65 decibels. The designed service life is 50 years in ordinary climatic regions, but structural inspections are required every 10 years, with intervals shortened by 20-30% in coastal areas with high salt spray or northern regions with freeze-thaw cycles. The 2024 regulations require a minimum protective coating thickness of no less than 30 millimeters for prefabricated components exposed to the environment. Fire protection codes specify the fire resistance limits of prefabricated concrete components: 3 hours for load-bearing walls, 2 hours for non-load-bearing walls, and 1.5 hours for floor slabs, with steel structures requiring fireproof coatings or fireproof panels for protection.
Construction Technique Standards ensure construction quality. Based on GB 50666-2011 'Code for Construction of Concrete Structures' and JGJ 1-2014 'Technical Specification for Prefabricated Concrete Structures', they regulate the production, transportation, hoisting, and connection of prefabricated components. The construction process should follow the sequence of foundation treatment, foundation construction, component installation, and roofing and waterproofing works, with a focus on handling details such as joint seams and waterproof layers to avoid leakage or structural defects.
Acceptance Criteria serve as the final checkpoint for quality control. Based on GB 50204-2015 'Code for Acceptance of Constructional Quality of Concrete Structures', they involve checking component dimensional deviations, appearance quality, and strength tests. After house completion, a comprehensive inspection of structural safety and usability is required, with third-party testing commissioned if necessary, to ensure construction quality meets standards.
