Residual compressive strength of locally corroded circular CFST stub columns: An experimental study

Circular concrete-filled steel tubular (CFST) columns are widely used in civil engineering structures due to their high strength, stiffness, and ductility. However, these columns are susceptible to local corrosion damage, which can reduce their load-carrying capacity and durability. This paper presents an experimental investigation of the impact of local corrosion on the residual compressive strength of CFST stub columns. The experimental program included 9 CFST columns, which were divided into two groups: G1 and G2. G1 specimens were subjected to actual electrochemical corrosion, while G2 specimens were subjected to mechanical damage to simulate the corrosion effect. The experimental results included the tested columns' corrosion profiles, failure modes, load-strain relationships, and load-carrying capacities. The main findings of this paper show that: (1) Different heights and thicknesses of corrosion profile representing the non-uniform localized corrosion. (2) Failure modes were mainly affected by the localized damage conditions, where the buckling occurred in the affected area. (3) Load-strain relationships exhibited elastic behavior initially, followed by nonlinear plastic behavior until reaching their ultimate compressive capacity. (4) The mechanical damage method can reasonably approximate the corrosion damage in CFST columns. This paper provides useful insights into the structural behavior of locally damaged CFST short columns.