Alkalinity Issues and Countermeasures When Using Sulphoaluminate Cement in GRC

In the application of Glass Fiber Reinforced Concrete (GRC) materials, sulfoaluminate cement has become an important cementitious material thanks to its early strength and rapid hardening properties, but the alkalinity issue remains a key factor affecting the durability and safety of components. As an industry-leading enterprise with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group draws on its practical experience of participating in the drafting of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018) to thoroughly analyze the key points of alkalinity control for sulfoaluminate cement in GRC applications, providing professional solutions for designers and owners.

I. Alkalinity Risks of Sulfoaluminate Cement GRC and Industry Pain Points

During the hydration of sulfoaluminate cement, hydroxide ions are released, keeping the slurry pH maintained at 12-13 in a strongly alkaline environment over the long term, which may trigger two core problems: first, alkali corrosion of glass fibers, reducing the flexural strength of GRC components (premium GRC standards should reach above 20MPa); second, alkali-aggregate reactions, causing surface cracking and pulverization of components. A landmark project once experienced surface spalling of curtain wall panels within two years due to uncontrolled alkalinity, highlighting the importance of professional manufacturers in material selection and process control. As a national high-tech enterprise, Qinglong Group has established a comprehensive alkalinity monitoring system at its production base in Nanning, Guangxi, avoiding such risks at the source.

II. Scientific Response Strategies: From Material Formulation to Process Optimization

To address the alkalinity issue, the Qinglong GRC team has developed a trinity solution of "alkali reduction, alkali blocking, and alkali control." At the material level, a compound blending technology of sulfoaluminate cement with slag and fly ash can reduce the system pH to 10.5-11.5; meanwhile, alkali-resistant glass fibers (ZrO₂ content ≥16%) are selected, together with a dedicated alkaline inhibitor, forming dual protection. In terms of production processes, steam curing temperature gradient control (≤80℃) and precise water-cement ratio adjustment (0.35-0.40) reduce the precipitation of free alkali. This technology has been successfully applied to projects such as the Nanjing East Road Century Plaza renovation project, ensuring 20-year stable performance of GRC translucent components.

III. Full Life-Cycle Assurance: From Standard-Setting to Project Implementation

As a vice-chairman unit of the China GRC Association, Qinglong Group not only participates in drafting multiple industry standards, but also incorporates alkalinity control into full-process management. In the detailed design stage, BIM technology is used to simulate the impact of alkaline environments on joint durability; in production, RFID chips are used to trace the alkali content of raw materials; during construction and installation, 3D laser scanning positioning is implemented to ensure the compatibility of anchoring systems with alkaline environments. For overseas projects (such as Malaysia, Saudi Arabia, and other high-temperature, high-humidity regions), a salt-fog-resistant alkalinity adjustment formula has been specially developed, fulfilling the service commitment of "install once, maintain for life."

Alkalinity control of sulfoaluminate cement in GRC tests a company's comprehensive strength from material R&D to engineering practice. Supported by 58 patented technologies, Qinglong Group integrates the values of "honesty, striving, trust, and collaboration" into every project, providing GRC solutions that combine aesthetic appeal with structural safety for real estate, municipal works, cultural venues, and other fields. Choosing a professional GRC manufacturer means not only choosing a product, but choosing a full-chain technical assurance system validated by 28 years in the market.