Boundary element model for bond problems in reinforced concrete members

Abstract A numerical procedure for the analysis of the bond stress distribution along the steel-concrete interface of reinforced concrete members is presented. Considering a reinforcing steel bar embedded in a surrounding cylinder of concrete, the analysis is based on a boundary element formulation in axisymmetric elasticity and on a local bond stress-slip nonlinear relationship which is able to model the contact interface behaviour observed by experimental tests. The results of practical application of the procedure to the case of uniaxial tension are in very good agreement with those presented by other authors using a finite element model and they are in sufficient agreement with those which for the particular scheme examined can be obtained by an analytical approach. The proposed model is advantageous with respect to a finite element model because it does not need special bond elements, allows a reduced number of unknowns and transfers the nonlinearity of the problem only to a number of equations equal to the number of nodal points at the contact interface.