Finite element modelling of permeability in brittle materials cracked in tension

In this work, a macroscopic model intended to predict the change of permeability with respect to cracking is proposed. The development reported here is implemented within an orthotropic continuum damage model able to calculate crack openings. The proposed model assumes an initially isotropic permeability tensor, which becomes anisotropic with damage. The objectivity of the hydraulic response toward the finite element mesh is ensured by considering the crack localization problem when building the permeability tensor. Finally, the model is used to simulate cracking and permeability variations on virtual and real structures. The simulation results are compared with experimental water flow rate measurements through a real reinforced concrete element subjected to tensile loading as found in the literature.