The behaviour of reinforced concrete structures is determined by the steel–concrete bond. Numbers of tests have shown that the nonlinear behaviour of the interface is mainly due to a progressive degradation of a concrete layer around the reinforcement. This chapter is a review of recent works done on the application of damage mechanics to this problem, in particular at the LMT where a nonlocal damage model is used to describe this phenomenon. A comparison with pull-out tests shows its capabilities to give information at the global level (nonlinearity and ultimate strength) as well as at the local level (strain evolutions on R bars). On the same kind of tests we show the ability of the model to predict a size effect consistent with experimental observations. The phenomena related to the realization of the anchorage at the bottom of prestressed concrete members are also described. Finally we present the simulation of the behaviour of an anchor bolt (those correspoding to the 1990 RILEM round-robin) in which the sensitivity of the boundary conditions is particularly pointed out.