Abstract
In the framework of nuclear power plants lifespan extension, the french institute for radioprotection and nuclear safety (IRSN) focuses on ageing of concrete-based nuclear power plant containment buildings. In this context, several studies carried out in the framework of the joint laboratory (IRSN/CNRS/University of Montpellier) MIST contributed to putting into place:- multi-scale experimental tests on concrete specimens ;- a numerical tool for modeling the cracking of cementitious materials.Carried out in the framework of the MIST, this PhD is the first rigorous confrontation between a prediction by the numerical tool of the MIST and experimental results. To do it, a three-point bending test has been put into place at the cement/aggregate interface scale on cement specimens and cement/aggregate composites. A complete experimental protocol is proposed for the extraction of informations (breaking force, surfacic displacement field, average crack speed) needed to the estimation of several material parameters used in the numerical simulations.These material parameters estimations are then used to numerically predict the cracking of a bigger concrete part contening tens cylindrical aggregates. An experimental/numerical confrontation is then carried out in order to assess the numerical tool predictive nature and to propose both numerical and experimental areas of improvement. Two of these areas of improvement that have been the subject of experimental studies are presented and lead to encouraging outlooks for the rest of this work.