Analysis of steel-concrete bond behavior by push-in test

This research aims at improving the knowledge about the behavior of reinforced concrete buildings. This behavior relies in particular on the steel-concrete link one, allowing to transfer stresses between the two materials. Knowing the bond behavior leads to optimise the structure design. The specific case of confinement vessels of nuclear structures induces a special link solicitation compared to the usual solicitations (such as presence of traction in the beam lower fiber). In order to study this stress state, a push-in test, less studied according to the literature, is set up. A new, precise and less-intrusive instrumentation by optic fiber is set up inside the concrete and the steel, giving access to local strains of both mediums. Much data is obtained at different steps of the steel-concrete interface behavior. Different interface lengths are used, leading to several rupture modes that are compared one to each other. The interface sliding one is more particularly studied. The behavior before the rupture, sometimes qualified as linear, is investigated as well. Post-mortem non destructive measurements (permeability and X-ray tomography) are finally performed. Known and new phenomena are observed and allow to refine the knowledge regarding the steel-concrete link. This research could lead to improve the modeling accuracy of reinforced concrete behaviors. Moreover, the uncertainty margins used in the engineering codes are likely to decrease. (author)