Multiphysics modeling of long-term aging effects on masonry structures: integrating weathering dynamics into structural numerical models

Environmental factors, projected to intensify due to climate change predictions, can expedite the degradation and aging of historic building materials. Among the primary degradation risks faced by porous building materials like masonry, salt crystallization stands out. Historical masonry quay walls that line canals - a vital component of the infrastructure of numerous European cities, notably in the Netherlands - present a unique case study in this aspect. This uniqueness arises from their continuous and long-term exposure, not only to environmental influences but also to salts in the canal water. To investigate this, a coupled multiphase modeling strategy for the hygro-thermal analysis of masonry structures is used to simulate the impact of salt crystallization on multi-wythe masonry quay walls in the city of Amsterdam. This modeling strategy is governed by four highly nonlinear and fully coupled differential equations addressing moisture mass conservation, salt mass conservation, energy balance, and salt crystallization/dissolution kinetics. The model has been previously validated against experiments in the laboratory, but it is here applied for the first time to a real case study. A parametric study adopting a 2D sectional numerical model of the quay wall was performed. Parameters investigated include the effects of boundary conditions at different faces of the quay wall, porosity of the material, salt concentration in the water, and masonry bond pattern.