Behavior of eccentrically loaded slender concrete-filled steel tubes with defect representing random local corrosion

Abstract

This paper focuses on the eccentric compression behavior of slender concrete-filled steel tubes (CFSTs) subjected to random localized corrosion and the localized corrosion was represented by a local defect. The randomness of corrosion includes the random locations and the random geometric characteristics that involve irregular corrosion profiles and uneven surfaces. Corrosion on the steel tube was represented by a defect in the experiment. The influence of spatial characteristics of local corrosion was investigated by seven CFST beam-column specimens, each featuring the defect in different locations along both height and circumferential directions. It was indicated through test results that both dimensions and locations of the defect considerably affected the failure mode and ultimate strength of the CFSTs. A numerical analysis was performed to confirm that local corrosion with irregular shape and uneven surface on a CFST beam-column can be approximated by a constant-depth circumscribed rectangular defect. Subsequently, a parametric analysis was conducted to find out how the corrosion dimensions, locations, and other critical parameters such as steel ratio, slenderness ratio, and material strengths influence the eccentric compression behavior of CFST. It revealed that negligible effects from local corrosion were observed in cases where slight corrosion was located near the column end. Finally, a calculation method was introduced to predict the ultimate strength of randomly localized corroded CFST beam-columns, with high precision.