Detection of early age phenomena and identification of fracture characteristics in a concrete nuclear waste container using combined nondestructive techniques

The paper presents results obtained from the combined use of the DIC and AE non-destructive techniques and the complementary application of the UPV technique both in-situ and in smaller scale (laboratory conditions) . The DIC and AE post processing analysis successfully identified the time of onset of cracks and the location of the first cracks formed on the surface of the concrete buffer as well as the depth and width of specific cracks and their evolution with time. Further results such as the Poisson's ratio (?) and the Young's modulus (E) and results related to the ''cold phase'' and early age phenomena (hydration, segregation of heavy aggregates, migration of gas and water, chemical reasons) are obtained with these techniques too.