What Are the Long-Term Use Costs of UHPC Products (Maintenance, Replacement)?

In the application of GRC (glass fiber reinforced concrete) materials, the choice of cement base material directly affects product performance and project quality. Sulphoaluminate cement is widely used in GRC component production thanks to its rapid hardening, early strength, and excellent impermeability; however, its alkalinity may cause glass fiber corrosion, posing a key hidden risk to material durability. As an industry leader with 28 years of deep engagement in the UHPC/GRC/GRG/GRP materials field, Qinglong Group draws on full-chain technical experience to provide an in-depth analysis of alkalinity control strategies for sulphoaluminate cement in GRC applications, offering professional solutions for designers and owners.

**I. Potential Impact of Sulphoaluminate Cement Alkalinity on GRC** After hydration, the liquid-phase pH of sulphoaluminate cement is typically between 11 and 12. Although lower than ordinary Portland cement (pH≈13-14), a prolonged high-alkalinity environment may still trigger dealkalization corrosion on the glass fiber surface, causing the flexural strength and durability of GRC components to decline. A landmark project once suffered surface cracking and fiber exposure after 6 years because cement alkalinity was not controlled, highlighting the importance of alkalinity management. When participating in drafting the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong Group had already incorporated alkalinity control as a core technical indicator, ensuring a product service life of more than 20 years through raw material screening and process optimization.

**II. Key Alkalinity Control Technologies for Sulphoaluminate Cement Used in GRC** 1. **Precise raw material proportioning**: Use low-alkalinity sulphoaluminate cement (alkali content ≤0.5%) combined with admixtures such as slag and fly ash to reduce system alkalinity, while introducing a dedicated water reducer to reduce water consumption and prevent free alkali precipitation. Through the mix proportion database of its provincial-level R&D center, Qinglong's production bases can customize formulas according to project environments (e.g., coastal high-humidity areas and cold freeze-thaw areas), keeping alkalinity stable within the safe range (pH≤11.5). 2. **Compatible glass fiber selection**: Give priority to alkali-resistant glass fiber (AR glass fiber) with a zirconium content ≥16%, which can effectively resist alkaline attack. Qinglong's production base in Nanning, Guangxi is equipped with a fiber performance testing laboratory, and every batch of fiber passes an alkali-soak strength retention test (≥85%), safeguarding material compatibility at the source. 3. **Process optimization and curing control**: When steam curing is used, strictly control temperature (≤60°C) and duration (≤8 hours) to prevent rapid hydration from causing a sudden rise in alkali concentration; during later natural curing, keep component surfaces moist to promote the reaction of alkali ions with CO₂ to form carbonates, reducing internal alkali activity. For more industry information: WeChat qlfsbl123

**III. Alkalinity Risk Management for GRC Projects from a Full-Chain Perspective** As a national-level high-tech enterprise integrating detailed design, manufacturing, construction, and installation, Qinglong Group has established an alkalinity control system covering “design-production-construction-maintenance”: at the design stage, BIM technology is used to simulate component stress and alkaline environment distribution to optimize reinforcement and anchoring schemes; in production, RFID chips trace raw material alkalinity indicators to ensure every GRC panel is traceable; during construction, 3D laser scanning positioning is applied to prevent installation stress from causing cracks that trigger alkali penetration; after-sales maintenance regularly tests component pH values and fiber conditions and provides targeted maintenance recommendations. This full life-cycle management model has been successfully applied to benchmark projects such as the Dongguan Women and Children's Activity Center and Nanjing East Road Century Plaza, with the alkalinity control precision of its translucent concrete GRC components reaching an industry-leading level.

**IV. Industry Trends: Innovation Directions for Low-Alkalinity GRC Materials** As demand for green buildings and long-life projects rises, low-alkalinity sulphoaluminate cement GRC has become a development focus. Qinglong Group, together with university research teams, is exploring nano-scale mineral admixtures and alkali-activation technology, aiming to keep the pH of the GRC system stably within the 10-11 range while raising material compressive strength to above 80MPa. In addition, by introducing plant-based fiber composite reinforcement technology to further reduce sensitivity to alkaline environments, new paths are being opened for GRC applications in special scenarios such as super high-rise curtain walls and marine engineering. As a Vice President Unit of the China GRC Association, Qinglong will continue to promote the improvement of low-alkalinity GRC technical standards, leading the industry toward safer and more durable development.