Modelling of perpetual pavement performance subjected to varying European three-dimensional truck tire loading

Abstract

There have been developments to the set-up of trucks in the European Union (EU). A significant development for pavement performance has been the widespread adoption of super single tires for truck trailer axles. This is in contrast to the US that has continued with dual tires for truck trailer axles. These EU trucks have particular operating conditions in terms of tire types, axle loading and inflation pressure. The three tire types used on a EU truck were modelled using finite element analysis for varying inflation pressures and varying axle loading. These loads were represented in the modelling as three dimensional (3-D) contact pressures with vertical, transverse and longitudinal contact pressure components. These loads were modelled as moving loads on a perpetual pavement with a visco-elastic surface course to understand the influence of these loads on the performance of the pavement. The pavement design and the material properties are from the Long Term Pavement Performance Program (LTPP). Surface cracking, top down cracking, bottom up cracking and subgrade rutting were assessed using key strains and the Mechanistic-Empirical Pavement Design Guide (MEPDG) predictive equations for the different loading combinations. It was found that there was variability in pavement performance for the different loading combinations with the steering axle giving lower performance than the drive axle for surface and top down cracking. The super single trailer tire gave the lowest performance across all the distress types. This means more than just axle loading is required to assess the distress caused by axles.