Local bond-slip model based on mechanical considerations

Bond between reinforcing bars and concrete plays a crucial role in the behaviour of reinforced concrete structures, often characterized by the bond stress-slip relationship. Numerous relationships exist in the literature, incorporating various parameters and calibrated with experimental databases. This results in a wide variety of analytical relationships and factors that are strongly affected by the experiments included in the database. In this paper, a thorough review of the literature is presented to identify the relevant parameters influencing the bond-slip relationship. On this basis, a bond-slip relationship for well-confined conditions is proposed combining analytical models for some aspects of the response and mechanical considerations to explain the considered factors. The results are compared with a database of 151 tests in well-confined conditions showing good agreement with the results. Additionally, expressions for other confinement conditions are proposed by adapting the model of the fib Model Code 2010 to provide a transition between the unconfined and the well-confined regimes.