In this paper, an analytical stress-strain model of confined concrete columns is developed and presented. The model is based on the extensively obtained data from tests of column specimens subjected to concentric compression loading. The tests included a wide range of varieties including both normal and high-strength concretes. The cross sections of the columns were of circular, rectangular, or elliptical shapes. The model incorporates the effective relevant parameters of confinement that have been observed to play important roles in confined column behavior like concrete strength, yield strength of transverse reinforcement, spacing between lateral confining element, and dimensional configuration of column specimen and its transverse reinforcement. The model can be used for concrete confined by spirals, rectilinear hoops, crossties, and combinations of these reinforcements.
The model demonstrates good predictive capability for concrete columns of compressive strength ranging from 20 MPa to 120 MPa. In addition, the model is shown to be applicable for a wide range of quantity and configuration of lateral reinforcement with volumetric ratio to concrete from 0.2% to 4%. The proposed model was compared with the existing experimental results. The comparison showed that the predicted stress-strain relationship obtained using the proposed model provides fine agreement with experimental results with respect to all considered parameters.