Long term durability of concrete structures, some waste disposals especially, is a problem which must be faced both from the point of view of cracking and physical degradations. In this contribution, we investigate the case of leaching of concrete structures…
Long term durability of concrete structures, some waste disposals especially, is a problem which must be faced both from the point of view of cracking and physical degradations. In this contribution, we investigate the case of leaching of concrete structures as an example. There are two sources of material damage: one which is due to mechanical actions, and a second one which is due to an increase of material porosity as several of its components are being dissolved. Experimental data aimed at exhibiting the influence of chemical damage on the fracture properties of the material are discussed first. Size effect tests, at various levels of calcium leaching, have been performed on mortar beam. The beams have been leached first and then they are loaded in order to obtain their residual strength. The experiments show that the stiffness and maximum loads are decreased upon leaching. The brittleness of the structures is increased and the fracture energy decreases. Then, we examine the relevance of an existing constitutive relation aimed at modelling mechanical and chemical damage. The interpretation of the size effect tests shows that the mechanical internal length of the material cannot be considered as a constant in the presence of chemical damage.