Impact of drying and wetting cycles on differed ettringite formation in concretes

• Published in: Materials and structures 2003-11, Vol.36 (263), p.587-593
• Main Authors: Pavoine, A, Divet, L, Fenouillet, S, Randazzo, V, Davy, J.-P.
• Format: Article
• Language: eng ; fre
• ISSN: 1359-5997
• DOI: 10.1617/13865

The Delayed Ettringite Formation (DEF) is an endogenous reaction which can sometimes be at the origin of concrete structure degradation. Until now, no selective predictive tool is available with respect to this pathology. This paper deals with some preliminary results of a study aimed at developing a predictive test based on drying and wetting cycles. Samples were heat cured at 80DGC for 10 hours or maintained at 20DGC. They were first subjected to drying (38DGC or 60DGC)/wetting cycles and then definitively immerged in water at 20DGC. The follow-up of longitudinal dimensions as well as SEM examinations allowed: to note the loss of selectivity of the test when drying is carried out at 60DGC, to detect in shorter time, potentially reactive concretes or not with respect to a DEF expansion, when drying is carried out at 38DGC. A test based on cycles whose drying is carried out at 38DGC, applied to concretes can thus be considered. Complementary studies are still needed to optimize and validate this test.