Numerical analysis of high-strength concrete columns interconnected by normal-strength concrete floor

The construction methods currently adopted for multi-story concrete buildings resorts the strategy to cast columns and slabs with high and normal compressive concrete strength, respectively. The intersection region affects the load transfer performance of the columns, causing expressive confinement stress in interior columns. However, when the confinement is only provided by two sides, as corner columns, it is not enough to increase the lateral stress. The structural behavior of corner columns, represented by isolated columns, also called sandwich column, is investigated in this paper through numerical nonlinear models. The lateral stresses induced by the uniaxial load applied to the sandwich columns are computed when the influence of concrete strength column-slab ratio, slab thickness and the column width ratio and the biggest dimension of the column's cross section were tested. A set of expressions were proposed to calculate the effective compressive strength of the column based on numerical results. The predicted effective strength has shown a good agreement with experimental results collected from the literature.