Water movement in porous building materials-X. Absorption from a small cylindrical cavity

The absorption of water from a cylindrical cavity is discussed in terms of the theory of water absorption by porous materials. The absorption process is analysed in terms of the sharp wet front model. Both theory and experiment show that the cumulative absorption from a cylindrical source varies as t 1 2 in the limit as t → 0 and that the time period for which t 1 2 beahviour is observed increases with source radius. A simple two-term approximation to the equation governing the absorption of water from a cylindrical cavity at longer times is developed. Three methods of data analysis are applied to experimental results on clay brick, aerated concrete and mortars to obtain estimates of the water sorptivity of these materials. © 1991.