A 3D visco-elasto-plasto damage constitutive model of concrete under long-term effects

A comprehensive 3D visco-elasto-plasto-damage constitutive model of concrete is proposed to analyze its behaviour under long-term and cyclic loadings. This model combines the visco-elasticy and plasticity theories together with damage mechanics. The work aims at providing an efficient model capable of predicting the material behaviour, taking into account timedependent effects at the mesoscale. The visco-elastic part is modeled within the framework of the linear visco-elasticity theory. The creep function is evaluated with the aid of the B3 model by Bažant and Baweja, and implemented via the exponential algorithm. The modified MenétreyWillam pressure-dependent yield surface, and a non-associated flow rule are used for the plastic formulation of the model. The damage part of the model considers two exponential damage parameters: one in tension, and one in compression, that account for a realistic description of the transition from tensile to compressive failure. After discussing the numerical implementation, the proposed model is calibrated, and numerical results at the mesoscale level are compared to experimental results.