| A plasticity model is developed using the Drucker-Prager yield criterion, which is appropriate for pressure-sensitive materials like concrete. The proposed plasticity model is focused on the prediction of behavior of concrete with constant confinement under uniaxial compression loading and on the volumetric compaction and dilation behavior.; An empirical axial stress-strain model is developed from existing empirical models in the literature. The proposed empirical axial stress-strain model satisfies certain theoretical conditions to correlate with the plasticity model, and has improved accuracy. Parameters needed to describe the axial deformation behavior are identified.; An empirical transverse deformation model is developed based on the plastic strain rate as a function of the axial strain. The model was developed considering the limitations of existing empirical models and test data for transverse deformation of concrete in the literature. The proposed empirical transverse deformation model provides reasonable behavior when studied in terms of several different transverse deformation variables (i.e., ηt, ϵ 3, ηs, and ϵv) and satisfies certain theoretical conditions that enable correlation with the plasticity model.; Parameters required for the plasticity model are identified and a procedure for estimating those parameters is completely described. The results of the plasticity models are compared to the results of the empirical models and to the test data in the literature. Based on the comparisons, values of the parameters required for the plasticity model are recommended, with certain conditions, and tabulated according to the concrete strength. Linear interpolation of the values of those parameters is studied and validated. These results enable the plasticity model to be applied to concretes with different strengths.; The behavior of concrete with constant confinement under uniaxial compression loading is investigated analytically. Concrete strengths ranging from 4 ksi (27.6 MPa) to 8 ksi (55.2 MPa) are considered. Confining pressures up to the 50% of the unconfined concrete strength are considered. |
