Anti-Rust Treatment Methods for GRC Curtain Wall Connections to Steel Structures?

Rust-proofing treatment for the connection between GRC curtain walls and steel structures is key to ensuring long-term system safety, and an appropriate protection scheme must be selected according to the service environment and connection type. From large-scale projects, Qinglong Group has developed a four-in-one anti-rust technical system covering material selection, surface treatment, structural design, and regular maintenance. In the Hainan International Convention and Exhibition Center project, we ensured the long-term reliability of the connection system in a high-temperature, high-humidity environment through measures such as hot-dip galvanized steel keels, epoxy-coated back bolts, and regular inspection and maintenance.

Material selection is the first line of defense in rust prevention. Qinglong recommends selecting appropriate steel and protection methods based on the environmental corrosion class. In C4 and higher corrosion environments, hot-dip galvanized steel should be used with a galvanized coating thickness of no less than 85μm. For critical locations, stainless steel may be used; 316 stainless steel is recommended for coastal areas. As for connection components, back bolts and hangers should all receive anti-corrosion treatment to avoid galvanic corrosion caused by contact between dissimilar metals. In the Xiamen International Conference Center project, this material selection strategy effectively prevented corrosion problems in the connection system.

Surface treatment quality directly affects protection performance. Steel surfaces must be thoroughly derusted before coating to reach the Sa2.5 standard. The coating system should be complete, including primer, intermediate coat, and topcoat, with a total dry film thickness of no less than 200μm. For connection components with complex shapes, electrostatic spraying can be used to ensure a uniform coating. Qinglong completes all anti-corrosion treatment of steel structures in the factory, avoiding the problem of on-site coating quality being difficult to control.

Structural design can effectively reduce corrosion risk. In its connection designs, Qinglong incorporates drainage holes to prevent water accumulation; uses insulating gaskets where dissimilar metals come into contact to prevent galvanic corrosion; and installs drip edges at panel joints to block capillary water channels. These detail designs reduce the accumulation of moisture and corrosive media at the source. In the Chimelong Zhuhai project, well-considered structural design kept the connection system in good working condition under the oceanic climate.

Regular inspection and maintenance is an important supplement to rust prevention. Qinglong recommends establishing a regular inspection regime for the connection system, focusing on coating damage, signs of rust, and loose connections. Localized rust discovered should be promptly surface-treated and repainted. A maintenance archive should be established to record each inspection and repair, providing a basis for preventive maintenance. Through refined protection over the full life cycle, the connection system between GRC curtain walls and steel structures can meet the required design service life.