Bond-slip in reinforced concrete structures, constitutive modelling and finite element implementation

In this paper, we present two principal items: anew formulation for a non-dimensional joint finite element (zero-thickness element) as well as an inelastic constitutive model for bonding phenomena between steel bars and concrete. For the first item, based on a typical four-node quadrilateral element, we developed a new 2D degenerated interface element which allows small normal strain and which is capable to treat the nonlinear tangential-normal behavior of bonding. About second item, the bonding behavior is expressed according to the small deformation and plane strain assumptions within the framework of thermodynamics and continuum damage mechanics. One of the most important contribution of this model consists in using a specific kinematics for contact allowing the implementation of standard constitutive relations.