How to Prevent Cracking of GRC Components During Setting? Crack Control and Qinglong Group's Process Optimization Solutions

Crack prevention during the setting of GRC components requires systematic, three-dimensional control through "material optimization, process control, and environmental management," focusing on reducing the combined effects of plastic shrinkage, thermal stress, and drying shrinkage. Based on 28 years of project practice, Qinglong Group applied measures such as adding polypropylene fibers (0.1% by volume), controlling the water-cement ratio at ≤0.33, and steam curing with gradient heating (≤15°C/h) in major projects including the wave-shaped roof of the Hainan International Convention and Exhibition Center and the hyperbolic curtain wall of the Wuhan Han Show Theatre, reducing the crack rate to below 0.2%. Scientific prevention not only ensures appearance but also enhances component durability, extending service life to over 50 years.

Material Mix Optimization Is the Foundation

Adding expansion agents (magnesium oxide type, 6-8% dosage) compensates for shrinkage, while polypropylene fibers suppress plastic cracks. Through maximum density packing design, Qinglong GRC achieves a shrinkage rate of ≤0.04%, far lower than ordinary concrete.

Precise Control of Process Parameters

Vibration time of 20-30 seconds to avoid over-vibration; demolding strength of ≥15MPa to prevent early damage; curing humidity of ≥95% and temperature of 20±2°C. At the Nanning production base, precise control is achieved through automated curing kilns.

Environmental Factor Management

When wind speed exceeds 5m/s, cover for curing; when temperature is below 5°C, apply heated curing. Qinglong Group has established an environmental monitoring system to adjust processes in real time.

Through systematic prevention and control, Qinglong GRC components achieve high strength and high durability.