Poro-Damage Approach Applied to Hydro-Fracture Analysis of Concrete

An approach using mechanics of saturated porous media is presented to model strongly coupled hydromechanical effects in concrete. Fracture mechanisms of the matrix are taken into account by introducing a tensorial damage variable, which makes it possible to describe orthotropic damage states as well as their effects on hydromechanical parameters (permeability and Biot tensor). An experimental procedure, allowing simultaneous control of pore pressure and applied stresses in a concrete specimen, leads to the identification of material parameters introduced in the constitute model. This model is implemented in the finite-element code CASTEM 2000; numerical simulations of a hydraulic fracture test are then performed and show that the damage-dependence of hydraulic parameters has significant influence on the global response of the structure.