National Standard for Prefabricated Concrete Houses
The national standard for prefabricated concrete houses mainly covers four major aspects: building materials, structural design, construction techniques, and acceptance criteria. The specific content is as follows:
Building Material Standards
Cement must comply with the requirements of GB 175-2007 'General Purpose Portland Cement' to ensure its strength, soundness, and other performance criteria are met. Reinforcing steel should meet the provisions of GB/T 1499.2-2018 'Steel for the Reinforcement of Concrete - Part 2: Hot Rolled Ribbed Bars', guaranteeing its mechanical properties and durability. Aggregates must be controlled for particle size, silt content, and other indicators in accordance with GB/T 14684-2011 'Sand for Construction' and GB/T 14685-2011 'Pebble and Crushed Stone for Construction' to avoid affecting concrete quality. Additionally, prefabricated components must adhere to GB/T 40399-2021 'General Technical Conditions for Prefabricated Components Used in Prefabricated Concrete Buildings', which specifies detailed requirements for material performance and dimensional tolerances.
Structural Design Standards
Structural design must follow GB 50010-2010 'Code for Design of Concrete Structures' and GB 50009-2012 'Load Code for the Design of Building Structures', clarifying the load-bearing capacity, seismic performance, and durability requirements of prefabricated components. For example, the dimensions, reinforcement ratios, and connection methods of main structural components (beams, columns, walls, etc.) must meet seismic fortification intensity requirements to ensure structural safety under extreme conditions such as earthquakes. At the same time, design considerations must account for stress changes during transportation and lifting to prevent component damage.
Construction Technique Standards
Construction techniques should comply with GB 50666-2011 'Code for Construction of Concrete Structures' and JGJ 1-2014 'Technical Specification for Prefabricated Concrete Structures', covering the production, transportation, lifting, and connection of prefabricated components. For instance, component production must control concrete pouring and curing conditions to prevent cracks; transportation requires secure fixation to prevent collisions; lifting necessitates accurate positioning to ensure precise connection nodes. The construction process includes foundation treatment, foundation construction, component installation, and roof waterproofing, with attention to details such as joint treatment and waterproof layer installation to prevent leakage.
Acceptance Criteria
Acceptance is based on GB 50204-2015 'Code for Acceptance of Construction Quality of Concrete Structures', inspecting component dimensional deviations, appearance quality (such as honeycombing and pitting), and strength testing (rebound method or core drilling method). After house completion, a comprehensive acceptance of structural safety (such as load testing) and usability (such as door and window operation, water and electricity flow) is required. If necessary, a third-party testing agency may be commissioned to verify construction quality and ensure compliance with design requirements.
