Stabilization effect on the hygrothermal performance of rammed earth materials

Abstract

The increasing interest in earthen materials is primarily driven by their hygroscopic and thermo-buffering capabilities, which contribute to their superior indoor air quality. Stabilization is the commonly used solution to enhance their mechanical and hygrothermal properties. The current study uses an experimental approach to investigate the impact of cementitious stabilizers on the hygroscopic properties and thermal conductivity of rammed earth materials. Measured hygroscopic parameters included sorption isotherms, moisture buffering capacity, and water vapor diffusion resistance factor. The hygrothermal experiments were conducted on the unstabilized specimens with different water masses ranging from 5 to 15% and on the stabilized specimens with different cement content ranging from 5 to 20%. Finally, three mathematical models of Halsey, modified Chung-Pfost and Oswin were applied to the sorption isotherm data. The results showed that stabilization positively impacted decreasing the heat conduction and improving the hygroscopic properties of rammed earth materials. Among the three models, the modified Chung-Pfost model was the best fit for sorption isotherms.