Thermal conductivity of hemp concretes: Variation with formulation, density and water content

TL;DR

This paper examines how formulation, density, and water content influence the thermal conductivity of hemp concretes through experimental and modeling approaches, highlighting density as the dominant factor affecting thermal performance.

Contribution

It provides new experimental data and modeling insights on the relative impact of density and moisture on hemp concrete's thermal conductivity.

Findings

Thermal conductivity ranges from 90 to 160 mW/(m·K) at 23°C and 50% humidity.

Density has a more significant effect on thermal conductivity than water content.

Increasing density by two-thirds raises thermal conductivity by about 54%.

Abstract

This study investigates the effect of formulation, density and water content on the thermal conductivity of hemp concretes. The investigations are based on experimental measurements and on self-consistent scheme modelling. The thermal conductivity of studied materials ranges from 90 to 160 mW/(m.K) at (23 degrees C; 50%HR). The impact of density on thermal conductivity is much more important than the impact of moisture content. It is shown that the thermal conductivity increases by about 54 % when the density increases by 2/3 while it increases by less than 15 % to 20 % from dry state to 90%RH.