Towards a better consideration of the interface bonding conditions in the design of bonded concrete overlays

This study investigates the effect of the interface bonding conditions between a concrete overlay and the existing hot mix asphalt layer on the design life of bonded concrete overlays. Most of the current design approaches assume a full bonding between the layers and ignore the proposed models in the literature for the description of the interlayer behaviour. A reason for that is that these models are very extensive and require big computation effort. To overcome this limitation, this paper analyses temperature-dependent experimental data, that describes the bond behaviour in normal and tangential direction and involves this data in different 3D finite element (FE) models for the evaluation of the impact of the interface bonding conditions on the pavement response. Further, the effect of applying different interface modelling approaches (full bonding model, friction model and the cohesive zone model (CZM)) in a commercial FE-software on the resulting design life has been demonstrated. One of the most significant findings to emerge from this study is that the implementation of temperature-dependent empirical data to describe the interface bonding conditions leads to more realistic design results.