Molecular dynamics study of the effect of moisture and porosity on thermal conductivity of tobermorite 14 \AA

TL;DR

This study uses molecular dynamics simulations to analyze how moisture and porosity influence the thermal conductivity of tobermorite 14 Å, a key component in cement paste, providing insights for designing better insulating materials.

Contribution

It offers new quantitative analysis of moisture and porosity effects on thermal conductivity of tobermorite 14 Å using molecular dynamics simulations.

Findings

Thermal conductivity increases with moisture content within pores.

The slope of conductivity increase decreases with higher porosity.

Normalized thermal conductivity grows exponentially with moisture volume.

Abstract

The effect of moisture and porosity on thermal conductivity of tobermorite 14 \AA~as the major component of cement paste is studied by using molecular dynamics simulation with ClayFF potential. The calculated results show that the thermal conductivity increases monotonically as the moisture content by mass within the interior pores increases and the slope of the linear fitting function decreases as the porosity increases. Meanwhile, the normalized thermal conductivity is found to increase exponentially as increasing the moisture content by volume. Phonon density of states of porous and moist tobermorite 14 \AA~is used to explain the contribution of individual atoms and molecules to the thermal properties. The results can be potentially used to design higher thermal insulating materials with cement and concrete for energy saving buildings.