Risk of Delayed Ettringite Formation in concrete heated at a mature stage: Experimental quantitative evidence

The conditions of development of Delayed Ettringite Formation (DEF) in concrete when submitted to excessive heating during hydration and setting have deserved recent research efforts and tend to be better understood. However, quantitative evidence of DEF risk for concrete submitted to similar heating when mature is still scarce. The experimental program described in this paper confirms the risk of DEF-induced expansion for concrete normally cured, then heated after 90 days of age, when further kept in saturated environment, both for a DEF-prone mix and for a concrete made with a low C3A, low SO3 and low-alkali content-cement.