How to Perform Steam Curing for GRC Components in Low-Temperature Environments? Winter Process and Qinglong Group's Constant-Temperature Assurance

Steam curing of GRC components in low-temperature environments requires overcoming four major technical challenges: "heating rate control, condensation prevention, temperature uniformity, and energy consumption optimization." The core lies in building a stable, uniform, and efficient humid-heat environment. For winter production in northern regions, Qinglong Group has developed a dedicated steam curing procedure: adopting a "stepped heating" regime (heating rate ≤10℃/h, then holding constant at 60℃ for 20-24h); reinforcing kiln insulation and installing condensate drainage channels; deploying sensors at multiple points inside the kiln to ensure temperature differences ≤5℃; and utilizing a waste heat recovery system to reduce energy consumption. During GRC component production for the Shenyang Culture and Art Center, with an outdoor temperature of -15℃, we used this process to successfully achieve demolding strength (>10MPa) in components within 24 hours, with not a single thermal crack. Low-temperature curing is not simply about raising the temperature—it is precise control of the humid-heat environment.

Preheating and Slow Heating Are Key to Crack Prevention

If freezing cold components (<5℃) are placed directly into a high-temperature steam environment, they will crack due to rapid thermal expansion of the surface. Components must first be preheated in the curing kiln with humid air no hotter than 30℃ for 2-4 hours, then heated slowly at a rate not exceeding 10℃/h to the target temperature (usually 60℃, lower than in summer).

Temperature Field Uniformity Determines Quality Consistency

In low-temperature environments, heat loss from the kiln body is significant, easily causing internal temperature differences. We use encircling steam pipes and a multi-point air inlet design, and reinforce kiln insulation (using 150mm thick rock wool). During curing, multi-point temperature sensors and automatic valves adjust the steam volume in each zone in real time to ensure uniform temperature.

Condensate Management and Humidity Assurance

Low-temperature steam easily produces large amounts of condensate when contacting cold components, affecting surface quality. We install water deflectors above the components and drainage channels at the kiln bottom. Meanwhile, the curing medium must be saturated steam with humidity maintained at ≥95% at all times to prevent moisture loss from components.

The climate can be cold, but process standards cannot be lowered. Through technical breakthroughs and equipment support, Qinglong Group achieves stable, high-quality GRC component production in all seasons and all weather conditions.