Determination of relative damage of asphalt pavement from reduced tire contact area

Abstract

Considering the traditional contact area which is a full circular contact area without any tread, in the current pavement design procedure, is an extreme overestimation of contact area and hence extreme underestimation of the real contact stress. Since the relationship between the contact stress and pavement damage is not linear but exponential, even a trivial difference between tire contact areas leads to significant difference in terms of induced pavement damage. This study was conducted to quantify the relative damage caused by realistic tire–pavement contact area with respect to the full contact area. Therefore, permanent deformation profiles of different contact areas at three tire load groups were obtained using an in-house Rotary Compactor and Wheel Tracker equipment and the relative damage analyses were done between tires with and without tread from various aspects. These aspects include operational life reduction ratio, rutting rate, linear and nonlinear relative damage concepts. It was concluded that on average real tires with tread cause 57% reduction in the operational life. In average, real tires with tread induce 1.23 times more mm per cycle. Based on linear relative damage analysis, in average, real tires with tread are 2.6 times more damaging. Furthermore, nonlinear relative damage analyses indicate that real tires with tread induce about three times more rutting compared to the worn-out control tread.