Thermal properties of ASR products

Abstract

Thermal and themo-mechanical properties of alkali-silica reaction (ASR) products are poorly studied. The existent property data refers to theoretical considerations and do not account for the fact that ASR products can be crystalline, nanocrystalline and potentially amorphous. Here, the thermal conductivity, heat capacity, and coefficient of thermal expansion of crystalline structures (based on Na-and K-shlykovite), nanocrystalline structure (based on defective K-shlykovite structures), and amorphous ASR product are calculated using molecular simulations. Semi-classical estimates of the thermal conductivity, heat capacity, and standard molar entropy are provided. The anisotropy of thermal conductivity and thermal expansion is quantified. Nanoacoustics parameters (sound velocities, phonon free path and relaxation time) are calculated. These results contribute to completing property data for ASR products.