Abstract: RC (reinforced concrete) columns in service in marine, coastal, and cold climate regions are prone to chloride ion erosion and to potential threats from explosions. Therefore, it is necessary to study the blast response and failure mechanisms of corroded RC bridge columns. In this study, RC columns subjected to significant uniformly distributed blast loads were investigated by using LS-DYNA, by exploring the blast response mechanisms of non-uniformly corroded RC columns, and by further exploring the impact of corrosion location on the failure mode and the sensitivity of blast response in RC columns with various corrosion locations to the corrosion ratio. The investigation results indicate that: the blast response of intact RC columns includes a transverse stress wave response stage, a flexural wave response stage, and a mixed response stage dominated by the global behavior. The corrosion of reinforcement exacerbates damage initiated by flexural waves and alters the internal force distribution of RC columns during the mixed response stage, collectively influencing the distribution of damage and the failure mode of the columns. Specifically, the corrosion at the top intensifies the bending-shear damage at the bottom of RC columns, dominating the failure mode; the corrosion at the middle has minimal impact on the failure mode of RC columns; while the corrosion at the bottom gradually shifts the damage to dominate the failure mode in the lower middle part of RC columns. The peak mid-span deflection of RC columns with corrosion at the middle shows the highest sensitivity to corrosion rate, whereas the failure mode of RC columns with bottom corrosion exhibits the highest sensitivity to corrosion ratio.