Finite element analysis of deterioration of axial compression behavior of corroded steel-reinforced concrete middle-length columns

The corrosion problem of steel-reinforced concrete (SRC) columns in coastal areas is becoming increasingly severe and needs to be solved urgently. This study established a numerical analysis model for SRC middle-length columns considering corrosion effects. The bond-slip constitutive relationship between corroded steel and concrete was established. It was found that when the rust rate is low, the bonding stress of SRC columns is slightly increased compared to those without corrosion. The ultimate and residual bonding stress will decrease significantly when the rust rate exceeds 1.5%. The comparison between the numerical analysis model and the experimental results shows that the establishment of the model is reasonable. Subsequent parameter analysis showed that for corroded SRC mid-length columns, the larger the slenderness ratio of the component, the faster the decrease in axial compression performance. The rust rate increased from 0 to 30%, and the axial compression performance of SRC columns decreased significantly. When the rust rate exceeded 30%, the axial compression performance of concrete columns tended to stabilize. A formula for calculating SRC middle-length columns' ultimate bearing capacity considering corrosion effects has been proposed.