Mechanistic–Empirical Study of Effects of Truck Tire Pressure on Pavement

Truck tire pressure plays an important role in the tire–pavement interaction process. As a traditional approximation method in many pavement studies, tire–pavement contact stress is frequently assumed to be uniformly distributed over a circular contact area and simply equal to the tire pressure. However, recent studies have demonstrated that the tire–pavement contact stress is far from uniformly distributed. In this study, measured tire–pavement contact stress data were input to a finite element program to compute pavement immediate responses for three tire configurations: single tires, dual tires, and dual-tire tandem axles. Computed critical pavement responses were input to pavement distress transfer functions to analyze further the effects of tire inflation pressure on pavement performance. Two asphalt concrete pavement structures–-a thick pavement and a thin pavement–-were investigated. Pavement responses at selected locations in the pavement structures were computed by the finite element program using the measured tire–pavement contact stress data and compared with the results predicted by a multilayer program using the traditional uniform contact stress method. The computation results showed that the multilayer program and the traditional tire model tend to overestimate the horizontal tensile strains at the bottom of the asphalt concrete and underestimate the vertical compressive strains at the top of the subgrade. Prediction of effects of tire pressure on pavement performance shows that increased tire pressure results in increased pavement distress due to both cracking and rutting and that tire inflation pressure is also related to the shape of pavement ruts.