Friedel's salt: Temperature dependence of thermoelastic properties

Abstract

Friedel's salt is an AFm phase playing a major role in immobilizing chloride ions in cement-based materials. This phase exhibits a displacive phase transition between 30 and 40 °C. Data on the physical properties of Friedel's salt and their temperature dependence is lacking in the literature. Here, we perform molecular simulations to compute Friedel's salt's elastic constants, heat capacity, and thermal expansion. AFFF, a force field focusing on AF-phases in cement systems, is extended to account for phases with chloride. We capture the temperature transition with the simulations, provide the thermoelastic properties as a function of the temperature, and assess the dynamics of water and chloride in Friedel's salt. Such information can be readily used in multiscale modeling requiring data on Friedel's salt thermoelastic properties.