Research on Key Steam Curing Techniques and Quality Control Measures for GRC Components in Low-Temperature Environments

Quality Control of GRC Components in Low-Temperature Environments: Steam Curing Technology and a Full-Process Quality Assurance System

In the field of architectural decoration materials, GRC (Glass Fiber Reinforced Concrete) has become the material of choice for large public buildings and high-end real estate projects thanks to its lightweight, high-strength and flexible forming characteristics. However, when the construction environment temperature falls below 5℃, the hydration reaction of GRC components slows down and strength development is hindered, making quality problems such as cracking and surface powdering likely to occur. As an industry-leading enterprise with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group has drawn on its full-chain technical accumulation to establish a systematic solution for steam curing of GRC components in low-temperature environments, ensuring that every link from detailed design to after-sales maintenance is precisely controllable.

I. Technical Challenges of Low-Temperature Environments for GRC Components and Curing Principles

The strength development of GRC components relies on the hydration reaction of cement-based materials. When the ambient temperature falls below 10℃, the hydration rate drops significantly; if the temperature drops to freezing point, the expansion of frozen free water may directly cause internal structural damage. Steam curing uses saturated steam to provide a stable temperature and humidity environment, accelerating the hydration process of cement clinker minerals and promoting the formation of C-S-H gel, thereby enabling components to reach early strength targets rapidly. Verified through more than a thousand engineering practices, Qinglong's technical team has shown that, in environments from -5℃ to 15℃, a three-stage temperature control curve (preheating at 40℃ → constant temperature at 60-70℃ → gradual cooling) can increase the 7-day strength of GRC components by more than 40% while effectively preventing micro-cracks caused by thermal stress.

II. Key Technical Points and Parameter Control of Steam Curing

Qinglong Group has established an intelligent steam curing chamber system at its production base in Nanning, Guangxi. The core technical points include:

1. Temperature Field Uniformity Control: A multi-group steam nozzle matrix layout combined with a PLC intelligent temperature control system ensures that the temperature difference inside the chamber is ≤±2℃, avoiding surface sanding caused by local overheating. For irregularly shaped components (such as hyperbolic curtain wall panels and openwork reliefs), an innovative zoned temperature control technology is adopted to ensure consistent curing conditions across all parts of complex shapes.

2. Coordinated Humidity and Pressure Regulation: The relative humidity inside the curing chamber is maintained at ≥90%, with pressure sensors monitoring steam saturation in real time to prevent drying shrinkage cracks. During the cooling stage, a gradient pressure reduction mode of 1℃/min is adopted to avoid structural stress concentration caused by sudden temperature changes.

3. Dynamic Optimization of the Curing Cycle: A curing cycle database has been established based on component thickness (50mm-200mm) and ambient temperature, generally controlled within 12-24 hours. For example, when producing 100mm-thick GRC exterior wall panels at -3℃, extending the constant temperature stage to 8 hours ensures that the 28-day flexural strength stably reaches above 18MPa, meeting the first-grade product requirements of the Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018).

III. Full-Process Quality Control System and Qinglong's Technical Advantages

As a national high-tech enterprise, Qinglong Group integrates steam curing technology into the full life-cycle management of GRC components:

• Material Source Control: Custom-grade alkali-resistant glass fiber (zirconia content ≥16%) and low-alkali sulphoaluminate cement are used to ensure interfacial bond strength in low-temperature environments. Every batch of materials undergoes third-party testing, with chloride ion content strictly controlled below 0.06%.

• Digitalization of the Production Process: BIM technology and an RFID chip traceability system are introduced to record key parameters such as real-time temperature curves inside the curing chamber and the number of component turnings, making quality problems traceable. In the Century Plaza renovation project on Nanjing East Road, this system raised the first-pass yield of translucent GRC components to 98.7%.

• Coordination of Installation and Maintenance: For low-temperature construction scenarios, dedicated anchoring joints (with freeze-thaw resistance of up to 300 cycles) have been developed, along with 24-hour response after-sales maintenance service. For example, in a landmark project in Malaysia, Qinglong's technical team remotely monitored curing data and successfully solved the component shrinkage problem caused by day-night temperature differences in a tropical highland region.

From the irregular GRC decorative components of Harbin Ice and Snow World to the weather-resistant cladding panels of the Moscow Metro in Russia, Qinglong Group has always upheld the philosophy of "meticulous craftsmanship and constant pursuit of excellence," transforming steam curing technology into a force for quality assurance in low-temperature environments. As an important participant in setting GRC industry standards, we understand deeply that true technical strength lies not only in solving today's construction challenges, but also in providing designers and owners with a full-chain, worry-free solution from concept to completion. Choosing Qinglong means choosing the technical certainty built on 28 years of professional accumulation, and a reliable commitment that every GRC component can still showcase architectural beauty even in low-temperature environments.