What Are the Anti-Rust Measures for Expansion Bolts in GRC Component Installation? Connection Point Protection and Qinglong Group's Anti-Corrosion Process

Anti-rust measures for expansion screws in GRC component installation require a tiered plan formulated according to environmental corrosivity, screw material, and application location, with the core being to block electrochemical corrosion paths. In coastal projects such as the Hainan International Convention and Exhibition Center, Qinglong Group adopts a triple anti-rust strategy of 'material upgrade + insulation treatment + sealing protection': preferably using 316 stainless steel screws (Cr 16-18%), paired with nylon insulating washers (thickness ≥2mm), and injecting silicone sealant into the screw holes, extending screw service life to over 30 years in C4 high-corrosion environments. Our practice shows that unprotected carbon steel screws rust and fracture within 3-5 years in coastal areas, while systematically protected screws remain as good as new after 10 years of use.

Screw Material Selection Is the First Line of Defense

Highly corrosive environments (such as coastal areas and chemical plants) mandate the use of 316 stainless steel screws with tensile strength ≥800MPa; general environments may use 304 stainless steel or hot-dip galvanized carbon steel screws (galvanized coating ≥50μm). Qinglong Group used 316 stainless steel screws in the Zhuhai Chimelong project, passing 3000-hour salt spray tests without red rust. Screw mechanical performance must reach grade 8.8 or above to ensure pull-out resistance ≥5kN.

Insulation Treatment to Block Galvanic Corrosion

Nylon washers (pressure resistance ≥50MPa) are added between the screws and the GRC substrate to prevent potential-difference corrosion between different metals. The washer outer diameter is 2-4mm larger than the screw head diameter, completely isolating contact. In the Shenzhen Yantian Port project, insulation treatment reduced galvanic corrosion current density to below 0.05μA/cm². For special locations, composite washers (nylon + stainless steel) can be used, balancing insulation and strength.

Sealing Protection and Regular Maintenance

After screw installation, silicone sealant (movement capability ≥25%) is injected into the holes to form a moisture barrier. Screw condition is inspected regularly (every 3 years), with anti-corrosion paint reapplied when necessary. Qinglong Group's anti-rust system ensures safe and reliable connection points.