When Is the Best Time to Demold GRC Components? — Research on Demolding Strength and Timing Control Technology

The selection of demolding timing for GRC components directly affects component quality and production efficiency, and must be comprehensively determined through strength monitoring, environmental assessment, and process optimization. Based on 28 years of production data, Qinglong Group holds that quality GRC components should reach a demolding strength of 15MPa or above, with demolding typically occurring 16-24 hours after casting. Through scientific timing control, the demolding damage rate has been reduced to below 0.2%.

Strength development is the foundation of demolding decisions. On-site testing with a penetration resistance apparatus or rebound hammer ensures that strength meets requirements. In the Shenzhen Yirui Biotechnology Building project, Qinglong Group controlled demolding strength within the 15-20MPa range through real-time monitoring, ensuring component integrity while improving mold turnover rates. Temperature affects strength development: under the standard 20℃ environment, components can be demolded after 24 hours; at low temperatures, the time should be extended appropriately—48 hours is required at 10℃. Steam curing can shorten demolding time to 8-12 hours, but heating and cooling rates must be controlled to avoid thermal stress cracks.

Component type affects demolding timing. Flat components develop strength uniformly and can be demolded relatively early. Special-shaped and thin-walled components require caution to prevent deformation caused by insufficient strength. In the production of complex-shaped components for the Wuhan Hanxiu Theater, Qinglong Group determined the optimal demolding timing through finite element analysis, ensuring precise component geometry. Mold design also affects demolding: a reasonable draft angle (≥3°) and a smooth mold surface facilitate smooth demolding.

Proper demolding procedures are essential. Remove the side molds first, then the bottom mold, with steady movements and no impact. Qinglong Group trains professional demolding workers who must hold certification to ensure standardized operations. Scientifically determining demolding timing delivers a win-win of quality and efficiency.