Evaluation of the Effect of Tire Loads with Different Contact Stress Patterns on Asphalt Rutting

Abstract

Road pavements are constructed to carry traffic which applies its load- to the pavement through the contact area between the tire and the pavement surface. Previously, the tire-pavement contact area and stresses were idealized, as appropriate instruments for quantification of these contact stresses were not available. The Stress- In-Motion (SIM) technology has made it possible to characterize these contact stresses at low speeds. In a recent Heavy Vehicle Simulator (HVS) test on various layers of Hot Mix Asphalt (HMA), the effects of non-uniform tire-pavement contact stresses were directly measured through application of two distinct types of tire-pavement contact stresses onto the HMA pavement. The rutting response of the pavement specifically showed the direct effects of these non-uniform contact stresses. In this paper the background to the tire-pavement contact stresses is discussed briefly, followed by details regarding the specific rut responses of five HVS tests where the pavement performance reflected the effects of the non-uniform tire loading conditions. Analysis of this data is presented together with discussions on the potential effects of this information on roads carrying real traffic and their rut development.