Desiccation shrinkage of concrete leads to formation of microcracks that damage mechanically concrete structures. It can be characterised by time variations of the material elastic properties. The main pur- pose of this study is to propose a simple modelling of…
Desiccation shrinkage of concrete leads to formation of microcracks that damage mechanically concrete structures. It can be characterised by time variations of the material elastic properties. The main pur- pose of this study is to propose a simple modelling of this phenomenon, and to validate it by experimentation. We first explain the basic hypothesis of our model, and propose to formulate hydric damage by using an iso- tropic scalar variable, proportional to decrease in water content. We assume the hypothesis of uncoupling between drying induced damage and classical mechanical damage. Solving the diffusion equation of water transfers in the cylindrical case, and after integration, we obtain the expression of the dimensionless stiffuess of a concrete cylinder as a function of time, and function of mass loss. These calculations are compared to ex- perimental results performed on cylindrical specimen with 110 mm diameter and 220 height. The parameters needed by the model are given by experimental kinetics of mass loss. A good adequacy between experimental results and modeling in term of drying induced damage is established. The impact ofhydric damage on tensile behavior is presented.