What Risks Can Excessive Chloride Ion Content in GRC Materials Cause? How to Control It?

Excessive chloride ion content in GRC materials severely threatens the long-term durability of products, particularly posing corrosion risks to reinforcing fibers and metal connectors. Qinglong Group strictly enforces an internal control standard of chloride ion content ≤0.1% (calculated by cementitious material mass), ensuring chloride ion content remains within safe limits through three measures: raw material control, production management, and testing verification. This stringent control gives Qinglong GRC excellent corrosion resistance in coastal projects.

Excessive chloride ions accelerate fiber corrosion. When Cl⁻ content exceeds 0.1%, corrosion cells form in humid environments, accelerating the alkali attack on glass fibers. Tracking data from Qinglong Group in Hainan's high-temperature, high-humidity regions shows that GRC panels with chloride ion content controlled below 0.06% retain over 90% of fiber strength after 5 years of use, while samples exceeding the limit show significant strength degradation. For metal embedded parts, chloride ions destroy the passivation film and initiate pitting corrosion, severely compromising connection safety.

Raw material control is the primary step. Qinglong Group tests the chloride ion content of every batch of incoming cement, sand, and admixtures, requiring sand chloride ion content ≤0.02% and using drinking-water-standard water for mixing. The production process strictly prevents cross-contamination, especially avoiding the mixing of sea sand in coastal areas. Finished products are regularly tested for chloride ion content using the acid dissolution method to ensure full process control.