Core Differences Between Standard and Economy UHPC in Performance Indicators and Analysis of Application Scenarios

Key Technical Points and Implementation Strategies for Steam Curing of GRC Components in Low-Temperature Environments

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete) has become the ideal choice for high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to its lightweight yet high-strength properties and flexible formability. However, when the ambient construction temperature falls below 5°C, the curing quality of GRC components directly affects product strength, durability, and project schedule. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP, Qinglong Group, leveraging its R&D strength as a national high-tech enterprise, has developed a scientific and rigorous implementation system for low-temperature steam curing, effectively solving the technical challenges of producing GRC components in severely cold regions.

I. Core Challenges of Low-Temperature Environments for GRC Component Curing

In low-temperature environments, the cement hydration reaction rate of GRC components decreases significantly, easily leading to slow strength development, surface cracking, loose internal structure, and other problems. With traditional natural curing at 0-10°C, the 28-day strength may only reach 60%-70% of the design value, and the components are vulnerable to freeze-thaw cycles. Through comparative experiments, Qinglong Group found that when the ambient temperature is below 8°C, steam curing can increase the 3-day strength of GRC components to 1.5 times that of standard curing while effectively suppressing alkali-aggregate reaction. This technical achievement has been incorporated as a compilation reference in the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018).

II. Key Technical Parameter Control in Steam Curing of GRC Components

The constant temperature and humidity curing workshop established at Qinglong Group's production base in Nanning, Guangxi, uses an intelligent temperature control system to achieve precise control throughout the entire curing process. Core parameters include: a heating rate controlled at 15-20°C/h to avoid thermal stress inside components caused by sudden temperature rises; a constant temperature stage maintained at 60-70°C with relative humidity ≥90% for 4-6 hours to ensure full cement hydration; and a cooling rate not exceeding 10°C/h to prevent surface shrinkage cracking. For extra-large special-shaped GRC components (such as hyperbolic decorative panels with a curvature radius ≤300mm), BIM technology is also used to simulate temperature field distribution and set up zoned temperature control devices. This process was successfully applied in the Nanjing East Road Century Plaza renovation project, ensuring the forming quality of translucent concrete components.

III. Qinglong's Distinctive Steam Curing Implementation Strategies

As Vice President Unit of the China GRC Association, Qinglong Group has innovatively introduced the "Three-Stage Curing Method": the pre-curing stage (20-25°C, 2 hours) promotes initial setting and prevents surface looseness caused by direct steam impact; the main curing stage uses saturated steam with pressure control to optimize the temperature gradient; and the post-curing stage gradually reduces the temperature to the ambient level, combined with 72 hours of spray moisturizing, stabilizing the moisture content of components at 8%-12%. This strategy has withstood the test of high temperature-difference environments in overseas projects in Malaysia and Saudi Arabia, with the 28-day flexural strength of components consistently reaching over 20MPa, far exceeding the industry average.

IV. Full-Chain Quality Assurance System

Qinglong Group deeply integrates steam curing technology with detailed design and manufacturing: at the design stage, finite element analysis is used to predict weak areas of components and optimize reinforcement schemes; in production, automated material distribution machines ensure uniform fiber dispersion, and combined with steam curing, the interfacial bond strength between glass fibers and the cement matrix is increased by 15%; at the installation stage, 3D laser scanning positioning achieves "zero-error" assembly. This full-chain service model has provided stable and reliable GRC component solutions for hundreds of projects of well-known real estate groups such as Poly and China Overseas, fully embodying the corporate mission of "Creating Aesthetic Architecture".

Facing complex low-temperature construction environments, scientific steam curing technology is the core guarantee of GRC component quality. Through 28 years of technical accumulation, Qinglong Group has deeply combined material properties, process innovation, and engineering practice, not only providing designers with broader creative space but also solving the pain points of low-temperature construction for owners. In the future, with the implementation of standards such as the General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC), Qinglong will continue to drive the technological upgrading of new architectural decoration materials and contribute more professional strength to industry development.