لماذا يُمنع رمل البحر في GRC؟ وما معايير رمل السيليكا المؤهل؟

The core reason sea sand is prohibited is the risk of chloride ion corrosion: when Cl⁻ content exceeds 0.06%, it destroys the SiO₂ network structure of glass fibers, causing strength to decay by more than 50% within 3 years. Qualified silica sand must meet stringent standards: SiO₂ ≥98%, mud content ≤0.3%, and chloride ion content ≤0.01%.

In an accident analysis of a seaside project in Zhoushan, GRC components that illegally used sea sand (Cl⁻ content 0.08%) showed large-scale fiber pulverization after only 2 years in service, with flexural strength dropping from 18MPa to 6MPa. Qinglong uses silica sand from Zhangzhou, Fujian, subjected to three-stage treatment—acid washing (HCl concentration 5%), water washing (water conductivity ≤50μS/cm), and drying (moisture content ≤0.5%)—to ensure Cl⁻ content ≤0.005%. This strict control enables products to pass 360-day salt spray tests without corrosion and perform excellently in coastal projects. The project also adopts migrating corrosion inhibitors (MCI), which form a monomolecular protective film on the fiber surface to further extend service life.

Harm Mechanism of Sea Sand

Chloride ions destroy the SiO₂ network structure of fibers. Salt crystallization pressure causes microcracks. Magnesium ions participate in harmful reactions. Shells in sea sand reduce strength.

Silica Sand Quality Requirements

SiO₂ content ≥98% ensures chemical stability. Mud content ≤0.3% reduces water demand. Mica content ≤0.5% prevents interlayer damage. Light material content ≤0.5% controls density.

Processing and Treatment Technology

Water washing removes chlorides and mud. Acid washing dissolves carbonate impurities. Magnetic separation removes iron particles. Drying controls moisture content ≤0.5%.

Testing and Control Standards

Chloride ion content is tested for every batch of sand. Alkali reactivity is spot-checked regularly. A supplier blacklist system is established. Compatibility tests are conducted before use.

Aggregate quality is the foundation of durability. Qinglong GRC has established dedicated sand supply bases to control quality at the source.