Effects of Core Hole Location on Symmetrical and Non-symmetrical Axial Loaded Column’s Capacity

Recent major earthquakes have highlighted the critical importance of assessing the performance of existing structures. Concrete mechanical properties stand out as crucial parameters for analysing the performance of reinforced concrete structures. While, various methods exist for determining these properties, core drilling is commonly regarded as the most reliable approach. Theoretically, taking cores from the beam tension zone does not significantly affect the results, but regulations often mandate cores to be taken from the vertical load-bearing elements as well. Although repair mortars can be used to fill core holes in structural elements, limited studies in the literature have revealed a decrease in axial load-carrying capacity for symmetric-loaded columns. While, the core is typically taken from the middle region of the columns under symmetrical loading, eccentric connections may occur in columns, where section reduction is applied on the upper floors, especially in the external axes. To the best of the authors’ knowledge, although the core’s effect has been investigated in a limited number of studies for symmetrically loaded columns, no significant study has been observed for eccentric loading. Accordingly, several parametric finite element analyses were performed to address this concern, including symmetrical and eccentric loading and different core locations on the same cross-section plane. Additionally, 16 cases were considered with stirrup conditions and various concrete and steel grade situations, and 160 finite element analyses were carried out with the Abaqus software. The study’s results revealed significant impacts of loading conditions and core extraction locations on the axial load-carrying capacity of the columns.