ABSTRACT
As stated before, the water permeability of materials or structures may be used as an indicator for the durability. The intention of the presented work was to link the water permeability to the crack pattern. It soon became apparent that the maximum crack width as well as the average crack width should not be used for the evaluation of the water permeability. Furthermore, the strain level is also not directly connected to the water transport properties since the resulting crack pattern will depend on the particular loading conditions. It is proposed to base the estimation of the water permeability on the actually observed crack patterns. The latter should be characterized by considering both the crack width distribution and the number of cracks. An attempt is made to link the characteristics of observed crack patterns to calculated theoretical water flow rates Qt whereby this calculation is based on the Hagen-Poiseuille equation (see eq. 1). Obviously, the crack width w is the dominant influence on the water permeability of an individual crack.
