Low-Temperature Steam Curing of GRC Components: Key Technical Points and Practical Guide

Low-temperature environments are a major obstacle in GRC component production. When the ambient temperature falls below 5°C, the cement hydration reaction slows dramatically or even stops, resulting in slow strength development and substandard performance. As an industry leader with 28 years of deep expertise in the GRC field, Qinglong Group has successfully overcome this challenge in numerous projects in low-temperature regions through its mature steam curing technology.

Steam curing creates a suitable temperature and humidity environment for GRC components, accelerating the cement hydration process and ensuring that components reach their design strength on schedule even in low temperatures. Qinglong applied steam curing technology in a municipal project in Northeast China, where GRC landscape components produced at -10°C maintained a 7-day strength compliance rate of over 98%, far exceeding the industry average.

Core Principles of Low-Temperature Steam Curing: Gradual and Gentle Curing

Steam curing must follow the principle of "slow heating, sufficient constant temperature, and gradual cooling" to prevent thermal cracking of GRC components caused by abrupt temperature changes. Qinglong's technical specifications require the heating rate to be controlled within 10°C/h, the constant temperature to be maintained at 40-50°C, the constant temperature period to last no less than 6 hours, and the cooling rate to not exceed 8°C/h. This standard was fully validated during the winter construction of the Hainan International Convention and Exhibition Center, effectively avoiding the risk of component cracking.

Key Technical Points of Steam Curing: Equipment, Environment, and Operation

Curing equipment should be a steam generator with controllable temperature and humidity, paired with a sealed curing shed to ensure even steam distribution and prevent localized overheating. Qinglong employs an intelligent temperature control system in production, monitoring the temperature and humidity inside the curing shed in real time and automatically adjusting the steam supply. In addition, ventilation channels must be reserved when stacking components, and steam pipes must not come into direct contact with component surfaces; before curing, the protective film on component surfaces must be kept intact to prevent surface dusting caused by direct steam scouring.

Qinglong's Hands-On Experience in Low-Temperature Curing: Tailored Solutions for Different Conditions

Qinglong optimizes curing solutions for different low-temperature scenarios. For severely cold regions of northern China, a three-stage curing process of "pre-curing + steam curing + post insulation" is adopted: components are first pre-cured for 24 hours in a 5-10°C environment, then steam cured, and finally covered with insulation materials for slow cooling. During the winter construction of the National Service center project in Singapore, the constant temperature period was adjusted to 8 hours to account for the region's large day-night temperature difference, ensuring uniform strength inside and outside the components. In addition, Qinglong adjusts the GRC mix ratio and adds early-strength agents to create a synergistic effect with steam curing.

Steam curing in low-temperature environments is not simply a matter of "heating and humidifying" but a systematic project that integrates equipment control, process adjustment, and operational standards. Through 28 years of project practice, Qinglong has accumulated extensive experience in low-temperature curing and developed standardized work procedures. With scientific steam curing technology, high-quality GRC components can be produced even in harsh low-temperature environments, providing a solid guarantee for the smooth progress of all kinds of projects.