When Is the Best Time to Demold GRC Components? Analysis of Influencing Factors

In the production and manufacturing of GRC components, the choice of demolding timing directly affects product quality, production efficiency, and cost control, making it a process step that Qinglong Group has placed particular emphasis on throughout its 28 years of full-chain experience. As a leading domestic GRC material supplier, based on our deep understanding of material properties, production environments, and engineering practice, we have summarized scientific criteria for judging demolding timing and an analysis of the influencing factors, providing a professional reference for the industry.

Core Criteria for Determining GRC Component Demolding Timing

The optimal demolding timing for GRC components must meet two key indicators: first, the material strength must reach the design requirements—typically compressive strength ≥15MPa and flexural strength ≥7MPa—which is the foundation for ensuring that components do not deform or crack during demolding; second, the bonding force between the component and the mold must be reduced to a minimum to avoid surface damage caused by excessive adhesion. Qinglong Group monitors the strength development of components in real time through embedded sensors. Combined with 28 years of engineering experience, demolding time is precisely controlled at 8-12 hours after casting (under normal temperature conditions), which ensures production efficiency while eliminating quality risks caused by premature demolding.

Four Key Factors Affecting GRC Demolding Timing

1. Material Mix Ratio and Fiber Content: The ratio of cement, quartz sand, and glass fiber in GRC material directly affects the rate of strength development. Qinglong Group uses its self-developed low-alkali cement formula combined with 6-8% alkali-resistant glass fiber, increasing the early strength of components by 30% and shortening demolding time by 20% compared with the industry average.

2. Curing Environment Temperature and Humidity: For every 10℃ increase in temperature, the strength development rate of GRC can increase by 1-2 times, but above 35℃ the surface tends to lose water too quickly. Qinglong's production base uses constant temperature and humidity curing kilns, controlling the ambient temperature at 20-25℃ and relative humidity above 85% to ensure uniform strength development. During winter construction, steam curing keeps the demolding cycle stably within 12 hours, solving the production efficiency problem in northern low-temperature environments.

3. Component Shape Complexity: For double-curved GRC components in projects such as the Dongguan Women and Children's Activity Center, stress concentration in their special-shaped structures requires the demolding strength to be raised above 20MPa. Qinglong uses BIM technology to simulate the stress distribution of components and applies local reinforcement processes to complex joints to ensure demolding safety.

4. Mold Type and Surface Treatment: Steel molds have smooth surfaces with low bonding force, allowing appropriately earlier demolding; wooden molds require extended curing time. Qinglong's self-developed nano release agent reduces the bonding force between mold and component by 40%. Combined with a custom steel mold system, damage-free demolding of the translucent concrete components for Century Plaza on Nanjing East Road was achieved.

Full-Chain Value Delivered by Scientific Demolding

Precise control of demolding timing is not only a guarantee of product quality, but also the key to Qinglong Group achieving full-chain coordination across "detailed design – manufacturing – construction and installation." Taking a landmark project as an example, by optimizing the demolding process, the component pass rate increased from 92% to 99.5%, on-site installation efficiency improved by 30%, and overall costs dropped by 15%. This process advantage has enabled Qinglong GRC to win the long-term trust of leading enterprises such as Poly and China Overseas in real estate, municipal engineering, overseas markets, and other fields.

As an enterprise that participated in drafting the Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Buildings, Qinglong Group has always regarded process details as its core competitiveness. Going forward, we will continue to further optimize the demolding process for GRC components through material innovation and intelligent production technology, providing the industry with more efficient and reliable solutions and fulfilling our mission of "Creating Beautiful Architecture."