Investigation of the Effects of Tire Pressure on the Responses of Geosynthetic Reinforced Asphalt Pavement Using Finite Elements methods

Increasing of tire inflation pressure in recent years is one of the main changes in truck loads characteristics which is highly effective on the interaction of tire and pavement. It results in the reduction of tire imprint surface area leading to the increase of pavement damage. Reinforcement of pavement using geosynthetic is one of the methods to overcome this problem. In this study, the effects of tire inflation pressure on the responses of a typical asphalt pavement reinforced by geosynthetic have been investigated. 3D Finite Elements method using ABAQUS has been utilized for pavement analysis and determination of pavement responses. Viscoelastic behavior was assumed for the asphalt layer and a method was developed for determination of the Proney’s series parameters for a typical asphalt concrete mixture used in Iranian pavements. Three types of geogrid with different elastic modulus has been utilized at three different positions in the pavement structure, and the effects of different tire pressures of 600, 750 and 900 kPa on the two critical pavement responses of the horizontal tensile strain at the bottom of asphalt layer and the vertical compressive strain on the top of subgrade have been investigated. It is found that, the tire pressure is mainly affect the horizontal tensile strain of the asphalt layer and the compressive vertical strain on the subgrade is not significantly affected by the tire pressure. The results also show the optimum position of the geogrid for reducing the horizontal tensile strain of the asphalt layer is at the bottom of asphalt layer and that for reduction of the compressive strain on the subgrade is beneath the sub-base layer. it is also found that the performance of geogrid in reduction of the tensile and compressive strain is not affected by the tire pressure.