Analysis of Chloride Ion Exceedance Risk in GRC Materials: Hazards, Control Strategies, and Qinglong's Quality Control System

Chloride ions are the "invisible killer" that erodes the durability of GRC materials; excessive chloride content directly threatens structural safety and service life. As a participant in the formulation of GRC industry standards, Qinglong has treated chloride ion control as a core element of quality management for 28 years, safeguarding the long-term value of every project with rigorous standards.

The risks posed by excessive chloride ions in GRC materials are hidden and long-term. Chloride ions accelerate the corrosion and aging of alkali-resistant glass fibres, destroy the interfacial bond between fibres and the cement matrix, and significantly reduce the flexural strength and impact resistance of GRC components. For GRC components containing steel frames, chloride ions penetrate the passivation film and cause steel corrosion; the volume expansion produced by corrosion leads to cracking and spalling of components, and in severe cases triggers safety accidents. Meanwhile, excessive chloride ions also aggravate alkali-aggregate reactions and reduce the freeze-thaw resistance and weather resistance of GRC. In long-term practice, Qinglong found that when chloride content exceeds 0.06%, the 5-year strength decay rate of GRC components exceeds 15%—a figure that provides an important reference for quality control across the industry.

Qinglong has established a full-chain chloride ion control system of "source control – process monitoring – finished product testing". For source control, raw materials are strictly screened: cement with a chloride content of ≤0.03% is selected, sea sand is strictly prohibited, and qualified silica sand with a chloride content of ≤0.01% is used. In the GRC curtain wall project of the Dongguan Women and Children's Activity Centre, Qinglong conducted dedicated chloride ion testing on every batch of aggregate to ensure that raw materials met standards. In process control, automated mixing equipment is used to prevent chloride contamination introduced by construction tools, admixture dosages are precisely controlled, and chloride-containing accelerators and antifreeze agents are banned. At the finished product testing stage, each batch of products is tested for chloride content in accordance with industry standards to ensure a finished product chloride content of ≤0.06%; products that fail testing are firmly prevented from leaving the factory.

As a national "Specialized, Refined, Distinctive, and Innovative" enterprise, Qinglong has well-equipped testing laboratories and a quality traceability system, and has built a technical barrier for chloride ion control through 58 patented technologies. In the Shanghai Qingpu R&D and production project, Qinglong's precise chloride ion control technology enabled GRC materials to maintain stable performance in a high-humidity industrial environment; in the overseas project in Saudi Arabia, the chloride ion control plan was further optimized for tropical desert conditions, ensuring that the products could adapt to the harsh climate. For owners and designers, chloride ion control is a key indicator in GRC material selection. Only by choosing a supplier with full-chain quality control capabilities like Qinglong can the safety risks and maintenance costs brought by excessive chloride ions be fundamentally avoided.