GRC Component Curing Period Standard: Falling Short of Minimum Days Reduces Both Strength and Durability

"Thirty percent production, seventy percent curing." The performance of GRC components depends not only on high-quality material formulations and refined craftsmanship, but an adequate curing period is also a key guarantee. Qinglong Group, with 28 years of GRC production and installation experience, has verified through thousands of project practices that a scientific curing period is the core prerequisite for GRC components to meet strength requirements and pass durability standards.

GRC components are composed of alkali-resistant glass fibres combined with a cement-based matrix, and their hydration reaction requires a suitable temperature and humidity environment along with sufficient time. If the curing period is insufficient, the hydration reaction will be incomplete, leaving defects in the internal structure of the components and directly affecting their performance. Comparative testing by Qinglong at its R&D and production project in Qingpu, Shanghai showed that the 28-day compressive strength of components with an adequate curing period versus those without can differ by more than 30%.

Minimum Curing Period Standards for GRC Components: 7 Days as Baseline, Extended for Special Scenarios

According to industry standards and Qinglong's practical experience, the minimum curing period for GRC components in conventional environments is 7 days. The first 3 days are the critical period for the hydration reaction, during which the surface must be kept moist to prevent rapid moisture evaporation; from days 4 to 7, humidity can be gradually reduced to promote steady strength growth. For hot and dry or cold environments, or for GRC components with complex shapes or thicknesses greater than 30mm, the curing period should be extended to 10-14 days. For example, in Qinglong's hotel project in Ouargla, Algeria, the curing period for GRC perforated panels was extended to 12 days due to the local high temperature and arid climate, ensuring the components met performance standards.

Core Hazards of Insufficient Curing: Inadequate Strength + Premature Aging and Cracking

An excessively short curing period will cause GRC components to fall short of design strength requirements, making them prone to deformation and damage after installation. More seriously, the insufficiently hydrated cement-based matrix inside will continue to react, easily producing shrinkage cracks later on, providing channels for moisture ingress and accelerating steel reinforcement corrosion and glass fibre aging. In a renovation project of an old residential community, Qinglong found that some GRC mouldings, which had originally been cured for only 3 days, showed large-scale cracking and chalking after just 5 years of use.

Qinglong's Standardized Curing System: Full-Process Quality Assurance for Components

As a National High-Tech Enterprise, Qinglong has established a comprehensive GRC component curing system. Production workshops are equipped with automatic spray curing equipment for precise temperature and humidity control; components stored outdoors are covered with geotextile for moisture retention and watered regularly; for shaped components in large-scale projects such as the Wuhan Han Show Theatre, steam curing combined with natural curing is used to ensure stable performance improvement during the curing period. Meanwhile, the Qinglong team develops dedicated curing plans based on the climate of the project location and the component types, safeguarding component quality at the source.

The curing period for GRC components is not a flexible indicator that can be lengthened or shortened at will, but a rigid standard that concerns engineering quality. With 28 years of industry experience, Qinglong knows well that an adequate curing period is the foundation for the long-term stable service of GRC components. Only by following scientific curing practices can the advantages of GRC materials—lightweight, high strength, and durability—be fully realized, creating long-term value for construction projects.