Computational simulation of the effect of crystallization inhibitors on salt transport and crystallization in porous materials

Abstract

Computational simulation of salt transport and crystallization in limestone depending on the presence of crystallization inhibitor in the dissolved salt is presented. The diffusion-advection model is used for the basic description of coupled water and salt transport, taking into account both water movement due to the moisture gradient and diffusion and dispersion effects within the liquid phase due to the concentration gradient. Salt crystallization in the porous body is modelled using an equilibrium model, taking into account the effect of crystallization inhibition. The effect of salt bonding on the pore walls is taken into account as well. The results of numerical simulations using a well calibrated computational model give evidence that in the analyzed case the use of crystallization inhibitors leads to the slowing down of both water and salt transport.

Molecular Crystallization Inhibitors for Salt Damage Control in Porous Materials: An Overview

“…Bearing this in mind, the development of numerical models has become ever more useful to compare the behavior of different salts, porous materials, or the effects of diverse climatic conditions. Currently, there are several models based on physical principles or empirical formulas [81,[122][123][124][125]. For instance, Espinosa et al [126][127][128] and Nicolai et al [123] developed coupled three-dimensional numerical models for heat-water-salt transport and salt crystallization in building materials by using the control volume method (CVM).…”

“…However, practically no reports are available in the literature, which deals with modeling salt crystallization phenomena in the presence of crystallization modifiers. More specifically, Kelnar et al [122] developed a diffusion-advection model for salt solution transport, which considered both water movement due to the moisture gradient and diffusion and dispersion effects within the liquid phase due to the concentration gradient. Salt crystallization in the porous medium was modeled using an equilibrium model, taking into account the effect of crystallization inhibition.…”

“…In this apparatus, moisture and free chloride concentration profiles were measured every two hours. Kelnar et al [122] demonstrated that in the process of drying of limestone saturated with NaCl solution, both water and salt ion (chloride) transport was slowed down by the presence of the inhibitor. This was ascribed to an increase of the viscosity of the salt solution and/or decrease of the interface tension in the pore walls.…”

Optimization methods for determination of moisture diffusivity of building materials in the drying phase

“…So far we used inverse analysis based on simple trial and error method, which was time consuming and also the achieved accuracy was not quite perfect [5]. Therefore we should find another solution that is more general and can be applied to a wide range of laboratory experiments.…”