Comparative study on the performance of serrated interfaces in multi-layer pavements

Bonding condition can significantly affect the performance of multi-layer asphalt pavements. This paper introduces a novel serrated interfaces design to enhance bonding condition between layers. Numerical studies on this model have been presented by using the non-linear finite element method. The multi-layer contact problem was solved by applying the Coulomb friction model and Lagrange multiplier methodology. To evaluate the performance of the serrated interfaces model, comparative studies with a fully bonded model and a smooth surface friction model have been conducted. Results suggest that the serrated interfaces model provides much more shear resistance than the smooth surface counterpart, and has similar performance as the ideal fully bonded model in terms of longitudinal and vertical displacements. Moreover, the serrated interfaces can change interfacial horizontal stresses into compressive ones, which is beneficial for preventing cracks at low temperature. Despite its limited effects on the reduction of vertical and shear stresses, the serrated interfaces should be a very promising development with appropriate designs and implementations.