Confinement effect of two-way beam-and-slab system on the effective compressive strength of interior concrete columns

Abstract

Multistory concrete buildings may resort to the strategy to cast columns and slabs with high and normal compressive concrete strength, respectively. Current design codes propose expressions to specify the effective compressive strength of interior columns confined only by flat slabs or beams with the same width as the column. However, when thin slabs and narrower beams are used, the confinement may not be enough to increase the lateral stress. The structural behavior of these interior columns is investigated in this paper using numerical nonlinear models. The influence of concrete strength column-slab ratio, the steel reinforcement ratio of the column and the beam, beam height and the column width ratio and the biggest dimension of the column's cross section were tested with and without vertical load on the beam. The results were compared with expressions found in the literature. © 2023 International Federation for Structural Concrete.