Axial Compression Behavior of Locally Corroded Slender Circular CFST Columns: An Experimental Study

Abstract

This study presents an experimental investigation into the axial compression behavior of slender circular concrete-filled steel tube (CFST) columns affected by localized corrosion. While CFST systems are known for their structural efficiency and durability, their performance under corrosion-induced damage—particularly in marine environments—remains insufficiently understood, especially for slender columns. Two full-scale CFST specimens were prepared: a control column and a corroded column with a mid-height defect induced through an electrochemical technique simulating localized marine corrosion. Both specimens were tested under axial compression with pin-ended boundary conditions. The results indicate that localized corrosion significantly alters failure modes, reduces load-carrying capacity, and compromises structural stability. The corroded specimen exhibited a 12% reduction in ultimate strength and experienced sudden failure, highlighting the vulnerability of slender CFST columns to corrosion-induced instability. The results provide preliminary insights into the combined effects of wall-thinning and reduced confinement in slender CFSTs, and serve as a basis for future research aiming to enhance the understanding of corrosion-damaged CFST structures.