Pavement Rutting and Deformation Performance Analysis through FEM

Rutting represents a severe, cumulative symptom of structural distress in flexible pavements, which occurs due to the accumulation of permanent deformation when subjected to repeated traffic loads and therefore adversely influences the quality of the ride, safety, maintenance life and costs. This study assesses the influence of the pavement layer thickness on the rutting depth using the three-dimensional finite element modeling (FEM) in the ABAQUS computing program. The flexible pavement system was built as a detailed numerical model with realistic material properties, nonlinear constitutive behavior and repeated loading in a static situation. There were nine pavement designs which varied in terms of the thickness of asphalt wearing course and base course, and evaluated stress distribution and permanent deformation. The findings showed that adding the pavement layer thickness has a significant effect on rutting depth, which is reduced due to the spreading of loads and the strain concentrations, especially in the asphalt and subgrade layers. On the other hand, thinner pavement layers had a greater deformation and they experienced faster rates of rutting at the same loading conditions. The results offer useful mechanistic information about the rutting behavior and contribute to the optimization of layer thickness of pavements to increase durability, sustainability and long service performance.