What Are the Consequences of No Anti-Rust Treatment After Welding Embedded Steel Bars? Corrosion Risks and Qinglong Group's Protection Practices

Failure to apply anti-rust treatment after welding embedded rebar will lead to catastrophic consequences: mill scale in the weld zone destroys the protective layer, forming electrochemical corrosion cells, with a corrosion rate 3-5 times that of unwelded areas, resulting in rebar cross-section loss, concrete cracking along the rebar, and reduced structural load-bearing capacity. Test data from Qinglong Group shows that in coastal environments, unprotected weld joints can reach a corrosion depth of 0.5mm within 2 years, with a 30% loss of load-bearing capacity after 5 years, severely threatening GRC curtain wall safety. In the Hainan International Convention and Exhibition Center project, through post-welding anti-rust treatment, the rebar corrosion rate remained ≤1% after 10 years of use, avoiding potential safety hazards.

Corrosion Mechanism and Hazard Analysis

High welding temperatures (1400-1600℃) destroy the rebar's passivation film, and residual weld slag forms corrosion initiation points. Corrosion products expand 4-7 times in volume, causing concrete cracking and spalling. In inspections at the Wuhan Han Show Theatre, cracks around unprotected weld joints reached 0.3mm in width, while protected weld joints remained intact.

Key Anti-Rust Treatment Technologies

Remove weld slag immediately after welding and apply an epoxy zinc-rich primer (dry film thickness ≥60μm). Use stainless steel electrodes for critical areas, or hot-dip galvanize after welding. Qinglong Group standards require a 100% pass rate for anti-rust treatment of weld joints.

Long-Term Monitoring and Maintenance

Regularly inspect the condition of weld joints and reinforce protection when necessary. Anti-rust treatment is key to ensuring the lifetime safety of GRC curtain walls.