Evaluation of Surface-Related Pavement Damage due to Tire Braking

摘要

The response of flexible pavement at near-surface is significantly affected by interfacial tire-pavement contact stresses. In addition to highly non-uniform vertical stresses and surface tangential shear stresses at tire-pavement interface, tire braking at an intersection causes additional significant longitudinal contact stresses on the pavement surface. In this paper, the flexible pavement responses to three-dimensional (3-D) tire-pavement contact stresses at various tire rolling conditions were determined using a developed 3-D finite element model. The hot-mix asphalt (HMA) layer was characterized as a viscoelastic material, and the transient dynamic tire loading was simulated using a continuous moving load and implicit dynamic analysis. The analysis matrix includes two typical flexible pavement structures (76 mm and 152 mm HMA thicknesses) and three tire rolling conditions (free rolling at high speed, free rolling at low speed, and braking). The study concluded that the low-speed vehicle loading and tire braking aggravates the pavement deterioration at an intersection in terms of rutting or shoving in the HMA and surface cracking at the pavement surface. During tire braking, the damage ratios for pavement surface cracking may be as high as 8 to 32 depending on HMA thickness, compared to the normal traffic loading conditions. The tire braking increases the HMA rutting or shoving potential by 2.0 to 2.6 times due to the increased shear strains in two directions. Hence, pavements for intersections should be specified, designed, and constructed differently than regular asphalt pavements to withstand the more severe loading conditions.