Axial compressive behavior of circular CFST stub columns with pitting corrosion

Concrete-filled steel tube (CFST) members are extensively employed in diverse structural applications due to their superior mechanical properties, remarkable economic benefits and construction convenience. However, these members are susceptible to corrosion during service, particularly local pitting corrosion, which typically occurs on the steel tube and causes substantial damage. This study investigates the axial compressive performance of circular CFST stub columns with pitting corrosion. Firstly, 12 specimens were tested and pitting corrosion was achieved by machining defects. Next, the finite element (FE) model of corresponding members was created, and the model's reliability was validated against the experimental observations. To account for the randomness of local corrosion, a detailed parametric analysis was conducted to explore the effects of various factors such as volume loss, corrosion depth, steel ratio and material strength on the axial compressive behavior of the columns. Based on both experimental and FE analysis results, a method for determining the bearing capacity of circular CFST with local pitting corrosion was developed, providing valuable insights for the evaluation and strengthening of corroded CFST members in practical engineering applications.