Effective Compressive Strength of Reinforced Concrete Columns with Intervening Floor Slab

This study presents an analytical model for estimating the effective compressive strength of a reinforced concrete (RC) column intersected by a floor slab made of relatively low-grade concrete. The proposed model is based on a theoretically sound background and considers the force equilibrium and strain compatibility conditions in the vicinity of the interface between the upper and lower columns and an intervening slab. By using the parametric study results obtained from finite element analyses, the effects of the confinement provided by the surrounding slab and the secondary stresses induced by the Poisson effect in the columns and slab panel zone were formulated in detail. A simple design expression was then derived for the better applicability of the proposed method for the estimation of the effective compressive strength of the exterior and interior columns with an intervening slab, in a unified manner. To verify the proposed model, the test results of 81 exterior columns and 24 interior columns were collected from the literature. It was found that the effective compressive strengths obtained by the proposed methods were in good agreement with these test results.