Beijing Prefabricated Building Component Molds
The prefabricated building component molds in Beijing are mainly steel molds, which have significant characteristics in terms of precision, component adaptability, production process coordination, and industrial chain collaboration. Quality inspection can refer to the 'Quality Inspection Standard for Prefabricated Concrete Components' (db11/t 968 - 2021).
Mold Types and Characteristics
Factories in Beijing primarily use steel molds, with the core advantage of high dimensional accuracy. The tolerance can be controlled at the millimeter level, far superior to the centimeter-level errors of wooden or plastic molds. This high precision ensures that components do not require secondary adjustments during installation, reducing on-site wet work and improving construction efficiency. However, steel molds have high initial costs and are heavy, making them less conducive to rapid mold changes. In contrast, plastic molds, while lightweight, are prone to deformation and struggle to ensure that the surface flatness of components meets standards, thus limiting their application scenarios.
Impact of Molds on Component Manufacturing
Mold selection needs to be balanced according to the type of component: non-load-bearing components (such as exterior wall panels) may use plastic molds to reduce costs, but this requires accepting compromises in surface flatness; load-bearing components (such as composite floor slabs) must use steel molds to ensure structural safety. Additionally, mold design needs to consider the difficulty of demolding during concrete pouring to avoid component damage due to demolding difficulties.
Coordination Between Molds and the Production Process
The climate in Beijing is unique, with low winter temperatures slowing down the concrete hydration reaction and dry conditions increasing the risk of surface shrinkage cracks in components. Therefore, temperature and humidity control measures need to be embedded in the production process, such as curing kilns equipped with insulation layers and hot air circulation systems, which work together with molds to ensure component quality. Although the thermal conductivity of steel molds may accelerate heat loss, this can be compensated for by optimizing the curing process (e.g., extending the insulation time).
Coordination Between Molds and the Industrial Chain
Component factories need to obtain BIM models from design institutes in advance, split the models into production drawings, and provide feedback on conflicts in the positions of embedded parts. During this process, mold design and production need to be coordinated with the industrial chain, with standardization of data interfaces being key. If design institutes use different versions of BIM software, component factories need to convert the formats themselves to ensure that mold parameters are consistent with design requirements, avoiding component scrap due to data errors.
Relevant Standards
The 'Quality Inspection Standard for Prefabricated Concrete Components' (db11/t 968 - 2021) issued by Beijing is a collaborative standard for the Beijing-Tianjin-Hebei region. It specifies inspection requirements for mold dimensions, surface roughness, etc., and is applicable to quality control of various types of molds, including steel and plastic molds. Component factories can establish mold acceptance processes based on this standard to ensure production compliance.
