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

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 capil lary water absorption is developed in order to determine water content prof iles and estimate the isothermal capillary transport coefficient De of Clay ey Aerated Concrete (CAC) at various porosities using the Boltzmann transfo rm resolution method. All experiments have been conducted at room temperatu re. A comparison of the evolution in capillary transport coefficient as a f unction of volumic water content obtained using this technique with the evo lution obtained using the gamma -ray attenuation for similar materials [J.A . Da Cunha Neto Bellini, Transport d'humidite en materiau poreux en presenc e d'un gradient de temperature: Caracterisation experimentale d'un beton ce llulaire, PhD thesis, Universite Joseph Fourier-Grenoble I, 1992, 69 PF; A. Bouguerra, Contribution a l'etude d'un procede de valorisation de dechets argileux: Comportement hygrothermique des materiaux elabores, PhD thesis, I NSA de Lyon, 1997, 116 pp.] confirms the relative reliability of this techn ique in estimating isothermal hydraulic diffusivity as a function of volumi c water content. (C) 2000 Elsevier Science Ltd. All rights reserved.