ABSTRACT
Permeability is that property of a material which permits the passage of liquid through its internal structure. The water tightness of concrete may be of greater significance than compressive strength, particularly in a water retaining structure. The movement of water through porous materials has many important consequences in building construction. In inhabited buildings the migration of water through porous materials influences the performance of the individual members and their fabric and underlies such practical problems as water penetration and rising damp. The capillary absorption of a liquid by a porous solid depends partly on the properties of the liquid and partly on the micro structure of the solid.
