New continuous strain-based description of concrete's damage-permeability coupling

International audienceThis contribution aims at improving the finite element modelling of concrete's damage‐permeability coupling using continuous and elastic‐based damage approaches. With this aim in view, a review of existing local and nonlocal damage formulations is performed showing how they differ in terms of damage estimation, crack propagation, and spatial discretization restrictions (when the energy‐based Hillerborg criterion is applied). Another critical review of damage‐based permeability laws is achieved to pinpoint their limitations. Indeed, the use of a bounded and strictly increasing damage variable does not allow (1) an accurate description of permeability in the presence of macrocracks that are physically unbounded and (2) a proper description of the permeability decrease as those macrocracks are closed. Accordingly, a new strain‐based permeability law is suggested. Its analytical validation is based on the BIPEDE tensile test for one loading‐unloading cycle. This new formulation intends to enhance the predictiveness of damage‐permeability coupling models leading to a better assessment of large structure's durability and serviceability