Simulation of Salt Crystallization-Induced Damage in Historic Porous Building Materials: From Moisture Transport to Micromechanics

This contribution presents a multiscale simulation framework for predicting salt crystallization-induced damage in historic porous building materials. At the microscale, crystallization pressure acting on pore walls is explicitly modeled using a damaging representative volume element (RVE). A macroscopic damage metric for the RVE is then derived for various time histories of crystallization pressure and pore-filling. The approach effectively combines moisture transport and salt crystallization at the macroscale by using a state-of-the-art multiphase model for transport and crystallization with micromechanical damage. In addition, a phenomenological damage model trained on data generated through micromechanical simulations on RVEs is developed to keep efficient the multiscale simulation framework. The proposed methodology is validated by comparing results with experimental data from salt-weathering campaigns on building materials. This multiscale simulation framework appears promising in tracking real-time the evolution of macroscopic damage along with salt transport and crystallization within the porous building material.