How Many Days Does GRC Component Curing Take at Minimum? Standard Curing Cycle and Specifications Explained

The curing period of GRC components is a critical stage for ensuring strength development and avoiding early cracking; an insufficient curing period can easily lead to performance degradation and reduced durability. Clarifying the standard curing cycle and scientific curing methods is core to guaranteeing component quality. Drawing on industry standards and production experience, Qinglong analyzes the key points below.

I. Standard Curing Period: The Core Basis of a Minimum of 28 Days

According to the "Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC)" (JGJ/T423-2018), the standard curing period for GRC components is at least 28 days. The first 7 days are a period of rapid strength development, requiring thorough moist curing to prevent moisture from evaporating too quickly; days 7-28 are a strength stabilization period, requiring appropriate temperature and humidity to promote full cement hydration. Qinglong's test data shows that after 28 days of curing, the compressive strength of GRC components can reach over 95% of the design value, and flexural strength over 90% of the design value. For special-shaped components, hollow-out components, or components produced in low-temperature environments, the curing period should be extended to 35-42 days to ensure fully stable performance. In the Panzhihua, Sichuan project, Qinglong extended the curing period to 35 days to address the high-temperature environment, safeguarding component quality.

II. Early-Stage Moist Curing: Key to Laying the Strength Foundation in Days 1-7

Days 1-7 are the critical stage of strength development for GRC components, requiring strict moist curing. Immediately after demolding, components should be covered with moisture-retaining geotextile or plastic film to prevent rapid evaporation of surface moisture; water should be sprinkled 2-4 times daily to keep component surfaces moist, with ambient humidity ≥90%. When steam curing is adopted, the temperature should be controlled at 50-60℃ with a heating rate ≤10℃/h, and after 48 hours of constant-temperature curing, cooling should proceed slowly to avoid cracking caused by thermal stress. Moving or stacking components during the curing period is prohibited to prevent mechanical damage. Qinglong's automated curing workshop achieves precise temperature and humidity control, ensuring effective early-stage curing and laying the foundation for strength development.

III. Mid-Term Stable Curing: Performance Optimization Stage in Days 8-28

During days 8-28, an appropriate curing environment must be maintained to promote stable improvement of component performance. Gradually reduce the frequency of water sprinkling and keep ambient humidity ≥70% to avoid cracks caused by alternating dry and wet conditions on component surfaces. Components should be stacked upright at an inclined angle of 10-15°, with rubber pads between layers for cushioning, and the stacking height should not exceed 3 layers to avoid deformation under pressure. Regularly inspect component surfaces and promptly treat fine cracks with a dedicated repair agent to prevent crack propagation. In the Nanning Jiahe City project, Qinglong effectively reduced the incidence of surface cracks to below 0.5% through mid-term curing management.

IV. Later-Stage Curing Management: Quality Assurance After the Curing Period Ends

After the curing period ends, follow-up protection must be carried out to ensure stable component performance. Strength testing should be conducted before components leave the factory; only components whose compressive and flexural strengths meet the standards may be shipped. Proper finished-product protection during transport and installation prevents edge damage and surface scratches. After installation, timely surface cleaning and protective treatment should be performed, applying a dedicated protective agent to enhance weather resistance. In the Shanghai Xinghewan project, Qinglong ensured that GRC components remained in good condition long-term after installation through full-cycle curing management, fully validating the importance of the standard curing period.