Behavior of stub SCFST columns with localized pitting corrosion damage

In this research, eleven square concrete-filled steel tubes (SCFSTs), including nine specimens with localized pitting corrosion damage and two intact specimens for the purpose of comparison, were tested under axial loading. The pitting corrosion damage was simulated by mechanically drilled cylindrical pits on the surfaces of the square steel tubes in the experimental study. The results from experiments suggested that the axial compression performance of the specimens with localized corrosion pits was different from that of the intact specimens. It was also revealed that pitting parameters, including the degree of volume loss, the number of rows and columns of pits, and the diameter-to-depth ratio of pits, have a significant effect on axial compression performance. Following the experimental investigation, the finite element models were established and validated by the experimental observations and curves, and extended to consider the random characteristic of pitting corrosion, to simulate true local corrosion cases. A parametric analysis was further conducted to explore the influence of random pitting corrosion damage on the ultimate strength of SCFST. Finally, a DoV-based method for considering localized pitting corrosion damage was proposed and applied in codified rules for predicting the ultimate strength of such damaged SCFSTs.