Analytical Study of Effects of Truck Tire Pressure on Pavements with Measured Tire-Pavement Contact Stress Data (05-1908)
Randy B. Machemehl, University of Texas, Austin
Feng Wang, Jackson State University
Jorge A. Prozzi, University of Texas, Austin

Truck tire inflation pressure plays an important role in the tire-pavement interaction process. As a conventional 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 inflation pressure. However, recent studies have demonstrated that the tire-pavement contact stress is far from uniformly distributed. In this study, the measured tire-pavement contact stress data were input to an elastic multi-layer pavement analysis program to compute pavement immediate responses. Two asphalt concrete pavement structures, a thick pavement and a thin pavement were investigated. Major pavement responses at locations in the pavement structures were computed using the measured tire-pavement contact stress data and compared with the conventional method. The computation results showed that the conventional method tends to underestimate pavement responses at low tire pressures, and overestimate pavement responses at high tire pressures. A two-way analysis of variance model was employed to compare the pavement responses in order to identify the effects of truck tire pressure on immediate pavement responses. Statistical analysis found that tire pressure was significantly related to tensile strains at the bottom of the asphalt concrete layer, and stresses near the pavement surface for both the thick and thin pavement structures. However, tire pressure effects on vertical strain at the top of the subgade were minor, especially in the thick pavement. In this paper, recent studies of truck tire pressure effects are reviewed; pavement structural computation methods are compared; analyses of pavement computation results are conducted and finally results and conclusions are presented.