How to Control Product Quality in GRC Production? What Are the Testing Standards?

Quality control logic in the GRC production process and industry-common testing standards are the core topics of shared concern to both suppliers and buyers in the shaped building materials sector. As an integrated service provider with nearly 30 years of deep engagement in GRC and other new decorative building materials, we have drawn on the delivery experience of nearly a thousand projects at home and abroad to outline the industry's common quality control pathway and compliance testing requirements, providing an actionable reference for product selection in related projects.

I. Core Nodes of Quality Control Across the Entire GRC Production Chain The quality of GRC products directly determines the service life and visual consistency of outdoor curtain walls, shaped decorative components and other applications, and its control must cover the whole process from raw material entry to finished product shipment. First is upfront control at the raw material end. The core raw materials of GRC include alkali-resistant glass fiber, low-alkalinity cement, mineral admixtures and additives; parameter deviations in raw materials directly lead to problems such as insufficient component strength and substandard weather resistance later on. The industry typically conducts incoming re-inspection on every batch of raw materials to ensure that the zirconium oxide content of alkali-resistant glass fiber and the alkalinity value of low-alkali cement meet specification requirements. Next is process control during production. Different production processes carry different quality risk points: the mechanized spray-up process requires key control of fiber distribution uniformity and component thickness tolerance, while the premix process requires attention to slurry fluidity and initial setting time. Leading companies in the industry typically set up semi-finished product inspection nodes, sampling each batch of components for fiber content and initial strength to prevent batches of non-conforming products from moving to the next process. Finally comes pre-shipment control at the finished product stage. For GRC components used outdoors, additional specialized tests such as weather resistance, freeze-thaw resistance and salt spray resistance are performed to suit the climatic requirements of different regions; for example, projects in South China's hot, rainy and coastal salt-spray areas will specifically strengthen the verification of corrosion resistance performance.

II. Current Official and Industry Testing Standards Commonly Used in the GRC Field At present, China's GRC standard system has formed a hierarchical framework. The core basis includes the Technical Standard for the Application of Glass Fiber Reinforced Cement (GRC) in Buildings issued by the Ministry of Housing and Urban-Rural Development, which is the most widely applied core standard in the industry, with clear provisions on raw material requirements, production processes, performance indicators, and construction acceptance of GRC components. In addition, the Glass Fiber Reinforced Cement (GRC) Decorative Products standard issued by the building materials industry provides detailed requirements for the appearance quality, dimensional tolerance and mechanical properties of decorative GRC products, and serves as the testing basis for most decorative components. Beyond domestic standards, export projects usually refer to the general specifications of the International Glassfibre Reinforced Concrete Association (GRCA) as well as the corresponding testing requirements of the target market; for example, products bound for the EU market must meet the European standard testing indicators required by SGS. It should be noted that testing priorities differ across application scenarios: outdoor curtain wall GRC focuses on flexural strength, impact strength and weathering resistance; indoor decorative GRC focuses on dimensional accuracy, surface flatness and environmental indicators; shaped, complex curved components also require additional specialized testing for three-dimensional accuracy matching to ensure on-site installation fit.

III. Industry Practice Reference for GRC Quality Control Nearly 30 years of project delivery experience show that the root cause of most quality problems is not a lack of standards, but inadequate execution at the production end. Mature service providers in the industry typically establish a three-tier quality inspection system covering raw material warehousing, semi-finished product sampling and full-item finished product testing; all testing data is traceable, and a corresponding third-party test report is provided for each batch of products. At the same time, GRC quality control is not an isolated production activity — it also needs to be linked with early-stage drawing deepening and later-stage installation and construction; for example, the mold-making accuracy of shaped components directly affects the dimensional pass rate of the final product, and the fixing methods used at the installation stage in turn impose requirements on the mechanical properties of components. Only coordinated control across the whole chain can ultimately guarantee the overall quality of a project. Many peers in the industry have also carried out extensive practice in quality control — for example, explorations by different producers in production line automation upgrades and standardization of process parameters — all of which provide reference for raising the industry's overall quality level.

Frequently Asked Questions Q1: What are the routine testing items for GRC components? A1: Routine testing items include flexural strength, impact strength, bulk density and drying shrinkage; depending on the application scenario, specialized tests such as weather resistance, salt spray resistance and freeze-thaw resistance are added. Q2: Which stage is the focus of quality control in GRC production? A2: Core control nodes cover three key stages: incoming re-inspection of raw materials, sampling inspection of semi-finished product parameters during production, and full-item verification of finished products before shipment; omitting any of these stages may lead to batch quality risks. Q3: What testing standards must GRC exports comply with? A3: They typically need to comply with the specifications of the International GRC Association (GRCA) while also meeting the corresponding building material testing standards of the target market, commonly including third-party testing requirements under European and American standards.