Residual bearing capacity of steel slag‐based artificial aggregate concrete‐filled steel tube ( <scp>SA</scp> ‐ <scp>CFST)</scp> columns after impact: Experimental and numerical analysis

Abstract This study investigates the residual bearing capacity (RBC) of steel slag‐based artificial aggregate concrete‐filled steel tube (SA‐CFST) following impact loading through experimental and numerical analyses. The experiment examines the failure modes of SA‐CFST during impact and the axial load–displacement curves after impacts. Finite element models are subsequently developed to analyze the influence of key parameters on RBC of SA‐CFST columns. A comparative analysis evaluates the differences in RBC among SA‐CFST, concrete‐filled steel tube (CFST), and reinforced concrete (RC) columns. The results indicate that deformation in the residual capacity tests is primarily localized at the impact point. RBC decreases with increasing impact energy or reduced boundary constraints. The axial compression ratio ( n ) below 35% of compression capacity has a beneficial effect on the RBC of SA‐CFST, whereas exceeding this threshold produces adverse effects. Excessive axial load leads to reduction in RBC. Under the same conditions, the RBC of SA‐CFST is slightly lower than CFST, with a difference of less than 10%. In comparison, SA‐CFST demonstrates 30%–60% higher residual capacity compared to RC columns, and this advantage becomes more pronounced with increasing impact energy. SA‐CFST members are proven to have excellent RBC after impact, making them suitable for use in structures prone to collisions.