Radial, bias, and wide-base radial single tires were tested in the laboratory under three levels of inflation pressures and axle loads. The measured characteristics of the tires were gross contact area, net cotire de9012 flection, and contact pressures. Distributions of the contact pressures were used in a mechanistic solution to predict various flexible pavement response parameters. A modified version of the bisar computer program, which takes concentric circles of various pressures, was used to predict the response parameters. The response of various flexible pavement structures was investigated in terms of the tensile strains at the bottom of the asphalt layer, the compressive stress at the asphalt layer interface, and the surface deflection. The effects of tire inflation pressures and axle loads on the response parameters were evaluated for all tires and asphalt thickness combinations. The three tire types were also compared for underloaded, loaded, and overloaded cases. This paper appears in transportation research record no. 1227, Rigid and flexible pavement design and analysis: unbound granular materials, tire pressures, backcalculation, and design methods.
Abstract