Risks of Excessive Chloride Ion Content in GRC Materials: Control and Prevention Measures

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete) is widely used in high-end projects such as grand theaters, commercial complexes, and landmark buildings thanks to its lightweight, high-strength, and versatile formability. However, excessive chloride ion content in GRC materials can become an "invisible killer" of project safety. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP, Qinglong Group will provide professional analysis for designers and owners, covering risk mechanisms, control standards, and preventive measures.

The harm of excessive chloride ions to GRC materials is both hidden and long-term. When free chloride ions penetrate to the surface of steel reinforcement, they destroy the passivation film and trigger electrochemical corrosion, causing the steel to expand in volume and ultimately resulting in cracking and spalling of GRC components, severely compromising structural safety. A landmark project once saw cracks appear in its exterior decorative lines five years ahead of schedule due to excessive chloride ion content, which not only increased maintenance costs but also caused irreversible damage to the building's aesthetics. When participating in the formulation of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong Group specifically emphasized that chloride ion content must be strictly controlled below 0.06%, a standard that has become an important basis for industry quality control.

Controlling the chloride ion content in GRC materials requires strict oversight of the entire process, from raw material screening to production technology. At the raw material stage, low-chloride cement (chloride ion content ≤0.03%) and alkali-free glass fiber should be preferred, while the chloride ion concentration in sand and gravel aggregates must be strictly tested. The "three-stage filtration" mechanism adopted at Qinglong's production base uses jaw crushers, cone crushers, and impact crushers for step-by-step screening, keeping the mud content of aggregates within 1% and reducing the risk of chloride ion introduction at the source. During production, the chloride ion content of mixing water is dynamically monitored, and electromagnetic flow meters precisely control water addition, ensuring that every batch of products meets internal control standards. For more industry information: +WeChat qlfsbl123

Preventing excessive chloride ions requires establishing a full lifecycle management system. During the design phase, Qinglong's detailed design team adds mineral admixtures (such as silica fume and slag powder) to GRC components based on the project's environment (e.g., coastal areas require higher resistance levels against chloride ion penetration), forming a dense microstructure that enhances the material's impermeability. During construction and installation, Qinglong's patented "dry-hanging" anchoring system is adopted to prevent chloride ions from penetrating through mortar during wet operations. For after-sales maintenance, Qinglong provides regular inspection services, using rebound hammers, rebar scanners, and other equipment to assess the health status of components and promptly identify potential risks.

As a national "Specialized, Refined, Distinctive, and Innovative" enterprise, Qinglong Group has always upheld the mission of "Creating Beautiful Buildings" and placed material safety first. From the GRC curtain wall project of the Dongguan Women and Children's Activity Center to the UHPC light-transmitting concrete project at Nanjing East Road Century Plaza, Qinglong has maintained a zero-exceedance record for chloride ion content. Choosing a GRC manufacturer with full-chain service capabilities is not only a guarantee of project quality but also a long-term investment in building safety. Going forward, Qinglong will continue to drive technological innovation in GRC materials, providing the industry with safer and more durable decorative solutions. For more industry information: +WeChat qlfsbl123