Anti-rust Treatment Methods for GRC Curtain Wall and Steel Structure Connections?

Anti-rust treatment for connections between GRC curtain walls and steel structures requires a four-dimensional approach of 'material anti-corrosion + surface treatment + joint protection + later maintenance', with the core goal of resisting connection failure caused by steel structure rusting. Through strict material selection and standardized processes, Qinglong ensures that connection joints achieve an anti-rust service life of ≥20 years, with multiple coastal and high-humidity projects free of rust hazards.

1. Material Selection: Improving Rust Resistance at the Source

Material selection is the foundation of rust prevention and must match the service environment. Steel structure material: Q355B hot-dip galvanized steel is preferred, with a galvanized coating thickness ≥85μm; stainless steel 304/316 structures are used in coastal or corrosive environments, and Qinglong uses 316 stainless steel for the steel structures of all its coastal projects. Connection fittings: anchors, bolts, and nuts are made of 316 stainless steel to avoid galvanic corrosion caused by contact with ordinary steel; all of Qinglong's connection fittings have passed salt spray tests (≥500 hours) with no rust. GRC material optimization: GRC density is increased (≥2.2g/cm³) to reduce chloride ion penetration; Qinglong's dedicated GRC has an impermeability grade of ≥P12.

2. Surface Treatment: Strengthening the Rust Resistance of Steel Structures

Surface treatment of steel structures is a key step in rust prevention. Rust removal: sandblasting is carried out before steel structure installation, achieving a rust removal grade of ≥Sa2.5 with no visible rust or oil on the surface; Qinglong controls surface roughness at 40-70μm after rust removal to improve coating adhesion. Anti-corrosion coating: after rust removal, two coats of anti-rust paint (epoxy zinc-rich primer) plus two topcoats (fluorocarbon paint) are applied, with a total coating thickness ≥150μm; Qinglong's coatings show no peeling or cracking after artificial accelerated aging tests (1000 hours). Contact surface isolation: anti-corrosion gaskets (butyl rubber, PTFE) are installed at the contact surfaces between GRC and steel structures to prevent direct contact between metal and cement; Qinglong's gaskets are ≥5mm thick with a compression deformation rate of ≤10%.

3. Joint Protection and Later Maintenance: Long-Term Guarantee of Rust Prevention

Joint sealing and maintenance extend the anti-rust service life. Joint sealing: gaps at connection joints are sealed with weather-resistant sealant (silicone or polyurethane) to prevent rainwater and salt spray from penetrating; Qinglong's sealant is fully compatible with steel structures and GRC, with no corrosive reaction. Drainage design: drainage channels are installed at joints to discharge accumulated water promptly and avoid rust caused by prolonged dampness; Qinglong's drainage channels have a slope of ≥3% with no risk of water accumulation. Later maintenance: annual inspections check whether the coating has peeled or the sealant has aged, and anti-rust paint is reapplied every 5 years; Qinglong's coastal projects are inspected every 6 months to address rust hazards promptly. Project case: the connection between the GRC curtain wall and steel structure at Hainan Poly Peninsula No. 1 adopted this four-dimensional anti-rust approach and has shown no rust after 8 years of use, with the connection joints remaining firm.