ABSTRACT
The durability of the material is of major concern to the owner, and may justify the extra cost of a material. It is determined by many laboratory tests aimed at evaluating the risks of degradation. Each of the tests provides an indication about the permeability of the material, just like actual permeability tests with a pressure gradient. The handful of theoretical considerations concerning the notion of permeability expounded in the appendix reveal the difficulties of interpretation that may arise with the many tests developed to evaluate the mechanisms of mass transfer of a fluid in a concrete. The same applies to the relation between the permeability of a concrete and the water tightness of a structure. With respect to durability, one of the main factors governing the resistance of a reinforced or prestressed concrete to corrosion of the reinforcements or tendons is the capacity of the concrete to maintain a passivating environment in their vicinity.
