Determination of the intrinsic permeability to water of cementitious materials: Influence of the water retention curve

Water transport is a key issue for concrete structures durability; the most important parameter may be the intrinsic permeability to water. It is usually estimated through inverse analysis on the basis of the experimental weight loss of concrete samples in a controlled environment. By doing so, Mualem’s model together with van Genuchten’s equation are used to describe the water retention curve as well as the relative permeability evolution. To study the influence of such a restriction, the intrinsic permeability of a modern concrete was estimated using different mathematical expressions to describe the water retention curve. A simple numerical procedure was set up to approximate the relative permeability evolution according to Mualem’s model. The results show that the intrinsic permeability depends on the model used whereas all the effective permeability evolutions tend to describe the same evolution. It is believed that in this evaluation process the obtained intrinsic permeability to water is not a fully relevant parameter for the effective permeability evolution.