Mechanics of ageing-from building to biological materials

In this work, we present a general model for the analysis of concrete and biological tissues as multiphase porous materials, with particular regard to their ageing. Such problems are typically multiphysics ones with overlapping domains where diffusion, advection, adsorption, phase changes, deformation, chemical reactions and other phenomena take place in the porous medium. For the analysis of such a complex system, the model here proposed is obtained from the microscopic scale by applying the Thermodynamically Constrained Averaging Theory (TCAT) which guarantees the satisfaction of the second law of thermodynamics for all constituents both at micro- and macrolevels. Moreover, one can obtain some important thermodynamic restrictions imposed on the evolution equations describing the material deterioration. Two specific forms of the general model adapted to the cases of cementitious and biological materials respectively are shown. Some numerical simulations, aimed at proving the validity of the approach adopted, are also presented and discussed.