Hysteresis performance of steel beam-column welded T-joints corroded in steel industrial atmosphere

This study investigates the effect of steel industrial corrosion on the seismic behavior of beam-column welded T-joints. An environmental and corrosion state survey in a sintering plant reveals high temperatures (up to 45 °C), high humidity (up to 58 %), and a high concentration of corrosive gases, particularly SO₂ (average 1.3 mg/m³, peak 5.4 mg/m³), contributing to extensive structural damage. Based on the measured environmental conditions, an accelerated corrosion test method is developed to replicate the full-scale corroded beam-column welded T-joints. The corrosion characteristics analysis indicates that the corrosion severity varies across different parts, with the lower flange of the beam experiencing the most corrosion, followed by the upper flange and web. Subsequently, hysteresis performance tests on five corroded T-joints examines the effect of steel industrial corrosion on their seismic performance, including the failure modes, hysteresis curves and skeleton curves, bearing and deformation capability, stiffness and energy dissipation. The results indicated that corrosion in T-joint specimens results in a linear decrease in loads and displacements at yield and peak points, accompanied by a significant reduction in stiffness and failure cycles. Corrosion impacts the ductility and energy dissipation of T-joints more than load-bearing capacity, affecting seismic performance more severely. Although corrosion allowance ensures the residual load bearing capacity, it's not cost-effective in mitigating the effect of corrosion on seismic performance of beam-column welded T-joints.