An Elastoplastic Damage Model for Concrete Subjected to Sustained High Temperatures

Quasi-brittle materials, such as concrete, exhibit plastic deformation and stiffness degradation under applied loading conditions. To predict the mechanical behavior of quasi-brittle materials, it may be necessary to combine elastoplasticity theories and continuum damage mechanics. An elastoplastic damage model is proposed within a framework that automatically meets the restrictions of thermodynamics. Both rate independent and rate dependent formulations are given. Specific evolution equations are given for a scalar isotropic assumption and results are compared with experimental data on concrete subjected to sustained high temperatures. The correlations between experiments and analytical solution in terms of plastic deformation and stiffness degradation are in good agreement.