Numerical modelling of the behaviour of consolidated porous media exposed to frost action

This paper summarizes the physical basis of a hydro-mechanical model whose components are the mass conservation equations of the solid matrix, water and ice. The constitutive laws of these three phases, used with Biot’s model and Darcy’s law for porous media, allow the strains of the medium and the various phase pressures to be coupled.The mechanical equilibrium equation leads to the final system of equations, the resolution of which gives the space and time variations of the stresses and strains.The interest of the physical formulation is to provide an expression for the hydrostatic pressure related to the presence of the phases in the porous volume, in the form of a liquid pressure and an additional term which can be deduced from the pore size distribution.The numerical code was implemented to test the capacity of this model to describe the strains observed in tiles subjected to freeze/thaw cycles. At present the model does not correctly reproduce the experimental strains. The importance of the boundary conditions is, however, highlighted.