Estimation of the capillary transport coefficient of Clayey Aerated Concrete using a gravimetric technique

Abstract Knowledge of the capillary transport coefficient is important to the study of moisture migration in building materials and therefore essential to the simulation of moisture movements predicted by mathematical models. In this paper, an experimental technique based on gravimetric measurements of capillary water absorption is developed in order to determine water content profiles and estimate the isothermal capillary transport coefficient D θ of Clayey Aerated Concrete (CAC) at various porosities using the Boltzmann transform resolution method. All experiments have been conducted at room temperature. A comparison of the evolution in capillary transport coefficient as a function of volumic water content obtained using this technique with the evolution obtained using the γ-ray attenuation for similar materials [J.A. Da Cunha Neto Bellini, Transport d'humidite en materiau poreux en presence d'un gradient de temperature: Caracterisation experimentale d'un beton cellulaire, PhD thesis, Universite Joseph Fourier-Grenoble I, 1992, 69 pp.; A. Bouguerra, Contribution a l'etude d'un procede de valorisation de dechets argileux: Comportement hygrothermique des materiaux elabores, PhD thesis, INSA de Lyon, 1997, 116 pp.] confirms the relative reliability of this technique in estimating isothermal hydraulic diffusivity as a function of volumic water content.