The main objective of this paper is to propose an evaluating equation for deformation capacities of reinforced concrete columns determined by flexural failure, which is caused by the compressive failure of the core concrete. The effects of the compressive failure of the core concrete become significant for corner columns subjected to varying high axial load. Therefore, these problems are discussed paying special attention to the effects of the varying axial load. The proposed equivalent axial load ratio was found to be effective to apply equations to columns with varying axial load.
