Reinforced concrete dapped-end beams’ strength assessment: comparison of analytical and numerical methods

Dapped-end beams are widely used for their advantages both in the horizontal elements of prefabricated buildings and as connecting elements between the cantilever and supported spans of a bridge. However, they represent critical elements, as their geometric configuration introduces very high concentrations and nonlinear development of stresses and the structural behaviour is influenced by the specific reinforcement layout. Therefore, it is crucial to deepen and evaluate the load-bearing capacity of these elements. Through the use of refined 3D finite element models, calibrated based on the results of an experimental campaign on dapped-end beams from the literature, nonlinear numerical analyses were conducted to replicate the structural behaviour at failure of the tested specimens. The numerical results were further compared with the ones obtained by the use of the strut-and-tie analytical method to assess the level of approximation of this latter with respect to the use of detailed numerical models.