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

The life of a building begins with its materials, and material safety determines a building's foundation. In the application of GRC (Glass Fiber Reinforced Concrete) materials, excessive chloride ion content acts like a hidden "building killer"—not only weakening material performance, but also posing structural safety risks. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group will provide professional solutions for designers and owners from three aspects—risk analysis, control systems, and prevention strategies—safeguarding the bottom line of building safety.

Excessive Chloride Ions in GRC Materials: A Chain Reaction from Microscopic Corrosion to Macroscopic Risks

The harm of chloride ions to GRC materials is hidden and cumulative. When the chloride ion content in materials exceeds 0.06% (by cement weight), it destroys the passivation film on the steel bar surface, triggering electrochemical corrosion and causing the steel bars to expand in volume by 30%-40%, which in turn leads to cracking and spalling of GRC components. In humid environments or coastal areas, this corrosion rate accelerates; in severe cases, it may cause instability of the curtain wall system and falling of decorative components, directly threatening the building's structural safety and service life. In addition, excessive chloride ions reduce the flexural strength of GRC materials (premium GRC can reach over 20MPa) and its durability, affecting its long-term aesthetic performance in high-end projects such as grand theaters and commercial complexes.

Full-Chain Control: Building Qinglong's Chloride Ion Defense Line for GRC Materials

As a national-level high-tech enterprise, Qinglong Group has established a chloride ion control system covering "design-production-construction." At the raw material stage, low-chloride cement (chloride ion content ≤0.03%) and chloride-free admixtures are strictly selected, and standardized sand and aggregates from the Nanning, Guangxi production base are used to reduce chloride ion introduction at the source; in the production process, patented concrete mix ratio technology (patent number omitted) and automated mixing systems ensure uniform chloride ion distribution, and each batch of products is tested by a third-party testing institution (such as the Guangdong Building Materials Research Institute) before it can leave the factory; during the construction stage, BIM technology is used to simulate installation nodes, avoiding the introduction of additional chloride ions through anchors or sealing materials, forming a closed-loop management of "pre-event prevention, in-process monitoring, and post-event traceability."

Prevention Strategy Upgrade: Technological Breakthroughs from Passive Response to Active Protection

For different application scenarios, Qinglong proposes differentiated prevention solutions: for projects in coastal high-salt-spray areas (such as the GRC curtain wall of a waterfront hotel in Malaysia), corrosion inhibitors (such as calcium nitrite) and cathodic protection technology are adopted to enhance the steel bars' corrosion resistance; in severely cold regions, the water-cement ratio and curing process are optimized to reduce the promoting effect of freeze-thaw cycles on chloride ion migration. Meanwhile, leveraging the R&D capabilities of its provincial engineering technology center, Qinglong has developed a high-performance GRC formulation with a chloride ion penetration coefficient ≤1.0×10⁻¹²m²/s, and participated in formulating the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), driving the upgrade of industry chloride ion control standards. In addition, Qinglong provides material selection consulting services for designers, recommending suitable solutions based on the project's regional environment—for example, control indicators can be appropriately relaxed in dry northern regions, while stricter standards are enforced in humid southern environments.

From the GRC special-shaped components of the Dongguan Women and Children's Activity Center to the translucent concrete project at Century Plaza on Nanjing Road, Qinglong has always controlled material safety with a "meticulous and excellence-driven" attitude. Controlling the chloride ion content of GRC materials is not only a technical requirement, but also a form of reverence for the life of a building. As a leader in the UHPC/GRC/GRG/GRP materials niche, Qinglong is willing to work hand in hand with designers and owners to build a solid material safety defense line with professional technology, so that every building can withstand the test of time and the environment.