What Are the Consequences of Not Applying Anti-Rust Treatment to Embedded Steel Bars After Welding?

Failure to apply anti-rust treatment after welding of embedded steel bars will lead to serious durability problems, affecting the long-term safety of GRC components. Based on extensive engineering practice and experimental research, Qinglong Group has systematically analyzed the hazards of this problem and the corresponding treatment measures. In the Qiangwei Garden project in Zengcheng, Guangzhou, we ensured the long-term reliability of the embedded system through strict anti-rust treatment and quality control.

Corrosion significantly reduces the effective cross-sectional area and mechanical properties of steel bars. Due to the high temperature at welded joints, the surface oxide scale is damaged and protective capacity decreases, making corrosion more likely to occur. The volume expansion of steel corrosion products generates tensile stress in the surrounding GRC matrix, causing cracking or even spalling of the protective layer. Qinglong's tests show that welded joints without anti-rust treatment will exhibit obvious corrosion within six months in humid environments, with corrosion depth reaching over 0.5mm after one year, severely affecting connection performance.

The expansion stress of corrosion products causes cracking of the GRC protective layer. When steel bars corrode, the volume of corrosion products can reach 2-4 times the original volume, generating enormous expansion stress inside the concrete. When the stress exceeds the tensile strength of GRC, the protective layer cracks and spalls. This not only affects aesthetics but also accelerates the corrosion process, forming a vicious cycle. This problem is particularly prominent in coastal area projects and requires special attention.

Corrosion affects the bond performance between steel bars and GRC. Corrosion products accumulate at the interface between the steel bar and GRC, weakening the bond between the two. Meanwhile, corrosion reduces the surface roughness of the steel bar, further deteriorating bond performance. Qinglong's pull-out tests show that the bond strength between severely corroded steel bars and GRC can decrease by more than 30%, severely affecting the load-bearing capacity of components.

Qinglong Group has established a comprehensive anti-rust treatment process. Surface cleaning is carried out immediately after welding to remove welding slag and oxide scale, followed by the application of a special anti-rust paint. For critical areas, epoxy-coated steel bars or galvanized steel bars are used to further enhance rust resistance. Through strict process control and quality inspection, we ensure that every embedded part receives effective anti-rust protection.