Relative Near Surface Pavement Performance for Dual and Wide-Base Tyre Assemblies Using a Finite Element Method

There is a need to assess the realistic tyre contact pressure created by a tyre in contact with a pavement. A traditional representation of tyre-pavement contact pressure is a circular uniform contact patch. This is overly simplistic, the contact pressure is a function of tyre type, axle loading and tyre inflation pressure (TiP). The research carried out considered dual tyre and wide-based tyre assemblies across a range of axle loading and TiP. These contact pressures were incorporated into a finite element package (CAPA-3D) and modelled on a thin pavement structure. The strains from this modelling were sorted to produce key shear strains associated with the key mechanisms of near surface pavement distress. The main distress mechanisms being top down cracking and asphalt cracking/rutting. This gave a method to fairly compare the dual and wide-based tyre assemblies with the same axle loading and TiP. The analysis gave interesting results for the different distress mechanisms of the pavement. The wide-based tyre gives consistently higher shear strains for all the areas of distress investigated. There is great variation in shear strains due to the different combinations of axle loading and TiP. It is clear that the wide-based tyre is a more damaging tyre for all combinations of TiP and axle loading. It is also apparent that how these factors interact has a great influence on the damaging potential of a tyre.