Bond-slip modelling of reinforced concrete lap splices subjected to low and high strain rates

This paper presents an analytical model developed to predict the flexural load-deformation behavior of reinforced concrete members containing tension lap splices. The proposed model incorporates the effect of reinforcement slip of the lap splice and the effect of high strain rates on bond characteristics and material properties of concrete and steel. The main advantages of the proposed model are that bond-slip phenomena are captured through the use of pseudo-material stress-strain relationships, rather than giving consideration to the continuum of reinforcement and slippage over the entire structural element. Material properties and associated dynamic increase factors (DIF) are defined using accepted formulations. A suitable bond-slip law is presented and modified to account for the influence of strain rates on bond characteristics. Beam failure criteria are expressed in terms of a flexural failure of the member or a bond splitting failure of the splice. A comparison of the analytical predictions with experimental data demonstrated that the proposed analysis technique can reasonably predict the flexural response of beams with tension lap splices. The results also show that the model is equally applicable for use at low- and high- strain rate loading, such as those generated during blast and impact loading.