Behavior of Reinforced Concrete Columns in Accordance with a Physical and Geometrical Nonlinear Numerical Model

Abstract

This paper presents a physical and geometrical nonlinear numerical model that has the objective to analyze the performance of reinforced concrete columns when under application of combined axial load and bending in steps until failure. In order to validate the model, data from tests in 9 reinforced concrete columns with 3000 mm in length, 250 x 120 mm in cross section, concrete strength around 40 MPa and geometric reinforcement ratio of 1,57% were used. All the columns were pin-ended and the main variable of the present work was the eccentricity of load in direction of minor inertia of the cross section. The obtained results about reinforcement strains, concrete strains, horizontal displacements and ultimate loads for the tested columns are presented and compared with the results obtained by the proposed numerical model. Polynomial functions of degree 3 were found to determine the ultimate load in the tested columns. The estimated results obtained by the numerical model are close to the experimental ones, being suitable for use in verification of elements under combined axial load and bending.