Influence of traversing crack on chloride diffusion into concrete

Assia Djerbi (1) , Stéphanie Bonnet (1) , Abdelhafid Khelidj (1) , Véronique Baroghel Bouny (2)

1 GeM - Institut de Recherche en Génie Civil et Mécanique
2 LCPC/BCC - Division Bétons et Composites cimentaires

This study examined the effects of traversing cracks of concrete on chloride diffusion. Three different concretes were tested: one ordinary concrete (OC) and two high performance concretes with two different mix designs (HPC and HPCSF, with silica fume) to show the influence of the water/cement ratio and silica fume addition. Cracks with average widths ranging from 30 to 250 mu m, were induced using a splitting tensile test. Chloride diffusion coefficients of concrete were evaluated using a steady-state migration test. The results showed that the diffusion coefficient of uncracked HPCSF was less than HPC and OC, but the cracking changed the material behavior in terms of chloride diffusion. The diffusion coefficient increased with the increasing crack width, and this trend was present for all three concretes. The diffusion coefficient through the crack D-cr was not dependent of material parameters and becomes constant when the crack width is higher than similar to 80 mu m, where the value obtained was the diffusion coefficient in free solution.

Mots clés: Traversing crack; Diffusion; Chloride; High performance concrete

Domaines: Mécanique des matériaux [physics.class-ph]; Génie civil

Assia Djerbi, Stéphanie Bonnet, Abdelhafid Khelidj, Véronique Baroghel Bouny. Influence of traversing crack on chloride diffusion into concrete. Cement and Concrete Research, 2008, 38 (6), pp.877-883. ⟨10.1016/j.cemconres.2007.10.007⟩. ⟨hal-01006980⟩