Viscoelastic Analysis of Geogrid-Reinforced Asphaltic Pavement under Different Tire Configurations

Abstract

The new generation of wide-base tires and the traditional dual-tire assembly are the main types of tire configurations used in the drive and trailing axles of trucks. However, the response of pavement to these configurations is not the same. Wide-base tires have more detrimental effects on pavement performance and less impact on the environment. The use of geosynthetics for reinforcing can improve the pavement performance against the detrimental effects of tires and prevent the occurrence of premature distresses. This research attempted to compare the performance of geogrid-reinforced and unreinforced pavement under both wide-base and dual-tire configurations by determining some of the critical responses of the pavement types. Viscoelastic analysis was conducted using the three-dimensional (3D) finite-element method in Abaqus software. A typical flexible pavement structure in Iran was used in all analyses. One type of high-modulus geogrid was used at the bottom of the asphaltic layer for reinforcement. Moreover, the distribution of the longitudinal and transverse tensile strains and the vertical shear strains throughout the thickness of asphaltic layer was determined. Results showed that, in general, under the same axle load, the single wide-base tire induced considerably higher strains than the dual tires. It was also found that under the same conditions, the maximum transverse tensile strain under the wide-base tire was approximately twice that under the dual-tire configuration. In addition, the results revealed that under dual tires, the distribution of the stains throughout the depth of the asphaltic layer was more uniform than that under the wide-base tire. It was also found that the geogrid reinforcement was significantly effective in reducing the critical strains. However, the reinforcement was observed to be more effective in reducing the tensile strains than the shear strains.