Effective compressive strengths of corner and exterior concrete columns intersected by slabs with different compressive strengths

In modern high-rise reinforced concrete buildings, high strength concrete (HSC) has been typically used for column members, while normal strength concrete (NSC) has been generally used for floor slabs. This study proposed a new analytic approach that can reasonably estimate the effective compressive strengths of corner and exterior column members intersected by lower strength concrete slabs. The proposed model was theoretically derived based on strain distributions and constraint conditions at an interface between column and slab members. In addition, the compressive strength test results of isolated, exterior, and corner columns intersected by lower strength concrete slabs reported in the existing literature were compared to the effective compressive strengths estimated by the proposed model. The proposed model provided good accuracy on the effective compressive strengths of the column members intersected by slabs cast with lower concrete compressive strengths. It was also shown that the proposed model successfully reflects the effects of the aspect ratio between the slab thickness and the column width on the effective compressive strengths of the test specimens and their failure modes that changed significantly according to the column-slab compressive strength ratio.