Influence of corrosion on loading capacity of circular concrete-filled steel tubular column

Concrete-filled steel tubular (CFST) columns are commonly used in engineering, especially in load-bearing structures. This study conducts an in-depth examination of how the axial resistance of CFST columns varies with random corrosion. A finite element model for circular CFST columns is developed and its accuracy is verified using available experimental data. The interaction between the outer steel tube and the concrete column is explored, along with the introduction of a strength reduction coefficient concept. Additionally, the concept of an axial load-bearing capacity reduction coefficient is introduced to illustrate variations in the axial resistance of circular CFST columns during different corrosion stages. The degradation patterns of reduction coefficients for uniform and random corrosion depths in the steel tube and CFST columns with varying mass loss rates are analyzed, and formulas are provided to predict the axial resistance in different corrosion stages. Furthermore, the study investigates the influence of variables such as material strength, component dimensions, and the thickness of the external steel tube, resulting in adjustments to the original expressions for various conditions.