PAVEMENT TESTING FACILITY--EFFECTS OF TIRE PRESSURE ON FLEXIBLE PAVEMENT RESPONSE AND PERFORMANCE. INTERIM REPORT

The effects of tire pressure on flexible pavement response and performance were evaluated using data from the first phase of research at the Federal Highway Administration's Pavement Testing Facility. The Accelerated Loading Facility testing machine was used to simulate traffic loading. The evaluation consisted of three components. First, deflections and strains for various combinations of load and tire pressure were measured and compared. Second, rutting and cracking for two test sections trafficked with the same load but different tire pressures were evaluated. Finally, changes in the pavement materials resulting from traffic were compared for the two sections trafficked with different tire pressures. These three evaluations showed tire pressure to be a second order effect. The effect of tire pressure on flexible pavement response and performance was less significant than the effects of load and temperature. During the response experiment, when load and temperature were constant, the effects of tire pressure could be observed. However, in the performance and materials evaluations, the effects of increased tire pressure were masked by differences in temperature.