Description of mechanical effects of salt crystallization in porous media

Abstract

This paper deals with mechanical analysis of the effects of salt crystallization in porous materials. The focus is primarily on the components of structural masonry, although the methodology is applicable to other materials used in construction (e.g. concrete, natural stone). First, the constitutive relations governing the inelastic deformation process in the presence of crystallization are formulated. Subsequently, a numerical study is carried out incorporating a sequential two-step scheme, whereby the distribution of salt precipitated within the porous domain is assessed through a transient framework for capillary uptake of saline water. The mechanical analysis accounts for the heterogeneity of strength properties at the macroscale as well as the propagation of damage. The simulations involve evaluation of the ultimate load of a brick masonry triplet at different stages of subflorescence. In addition, a heuristic example is provided involving the case when the triplet is subjected to a sustained lateral load under a prescribed history of salt deposition.