Why Is Sea Sand Prohibited in GRC? What Are the Standards for Qualified Silica Sand?

The strict prohibition on using sea sand in GRC stems from the corrosion risk its chloride ions pose to glass fibres and metal components. Qinglong Group strictly enforces a sand standard requiring chloride ion content ≤0.02%, giving priority to high-quality silica sand with quartz content ≥95% and mud content ≤1%. This stringent control ensures the long-term durability of GRC in harsh environments and prevents engineering risks caused by material issues.

The chloride ion content in sea sand typically exceeds 0.1%, far above the safety limit. Qinglong Group conducts rapid testing when raw materials arrive on site to ensure sand safety. Qualified silica sand must meet a fineness modulus of 2.3-2.6 and have a continuous particle size distribution to ensure a dense slurry. This stringent control is the foundation of quality assurance.