Tire Contact Pressure and Its Effect on Pavement Strain

This paper reviews current knowledge of the three components of pavement contact pressure developed by a free‐rolling tire. A finite element tire model employed to calculate tire‐pavement contact pressure is described. These pressure distributions were used as pavement surface load input data for a pavement model (ILLIPAVE). The ILLIPAVE program utilizes a nonuniform tire contact pressure distribution in calculating the strains in a flexible pavement on a granular base. Results from the tire study indicate that, for a 10.00‐20 bias‐ply truck tire, the highest pressure in the tire‐pavement contact region is about two times the inflation pressure, for the 517‐kPa and 862‐kPa (75‐ and 125‐psi) inflation pressures considered. The analytical studies on flexible pavements were conducted primarily on thin pavements, since the effects of tire pressure are most pronounced in thinner sections. The results indicate that these truck tire contact pressures produce high tensile strains at the bottom of the pavement. It is found that nonuniform pavement contact pressure, as produced by a real tire, causes significantly higher pavement strains than those calculated with the conventional assumptions of uniform contact pressure.