A three-dimensional finite element model for confined concrete structures

Developed in this article is a finite element model for the analysis of concrete under uniaxial, biaxial and triaxial compression and the modelling of confined reinforced concrete structures failing in compression. The model uses the microplane formulation to develop the constitutive relationships using parameters obtained from the back analysis of a concrete cylinder under various confining pressures. Numerical examples are presented for the modelling of tied concrete columns loaded in concentric compression, with cover spalling included in the model. A good correlation was observed between the experimental and numerical data, both before and after the peak axial loading.