Strength of Slender Reinforced Concrete Columns

Abstract

This paper presents a numerical method, based on a simple transformation concept, for analyzing the failure loads of slender reinforced concrete columns under uniaxial bending. Both material and geometric nonlinearities are taken into account; this method is applicable to material failure and buckling failure. The concrete and steel of the critical section are transformed into an equivalent material, which is homogeneous and linearly elastic, by using the secant modulus ratio; the cross-sectional width parallel to the neutral axis accordingly expands or contracts. The modulus of elasticity of concrete as proposed by Carrasquillo and colleagues is used as the basis for transformation. A numerical example is presented to illustrate the method. For 82 columns in six experimental investigations carried out in the past by other researchers the predicted failure loads are as close as the predictions of the P-Delta method and generally closer to the experimental values, compared with the predictions of ACI 318 and EC 2. The proposed method allows for rapid and accurate analysis of the failure load of slender columns.