Abstract
The present work is devoted to modelling of plastic deformation and damage in cementβbased materials subjected to desiccation and mechanical loading. Basic mechanical behaviours of cementβbased materials and influences of saturation degree on such behaviours are first recalled. Physical mechanisms of damage induced by desiccation process are analysed. An elastoplastic damage model is then proposed for the description of mechanical responses, taking into account the transition from brittle to ductile behaviours with the increase of confining pressure. The model is further extended to unsaturated conditions: a specific damage driving force and generalized effective stress concept for plastic flow are proposed. The procedure of determination of model's parameters is presented. The proposed model is applied to a standard mortar subjected to desiccation process. The main features of mechanical behaviours as well as the influence of saturation degree are correctly described by the proposed model. In particular, the kinetics of desiccation and related damage evolution are well reproduced. As an example of application, the responses of a concrete beam in threeβpoint bending test with different desiccation conditions is investigated. Again, the numerical simulations are in good agreement with the experimental data. Copyright Β© 2010 John Wiley & Sons, Ltd.