Modeling of pavement response using nonlinear cross-anisotropy approach

The multidepth deflectometer (MDD) is used to estimate flexible pavement response subjected to permitted overweight truck traffic (gross vehicle weight up to 556 kN). This study focuses on using material constitutive models to assess the most accurate and reliable pavement layer behavior. Deflections from MDDs installed on tested pavement section were compared with predicted ones using different material constitutive models to determine the best model. As a result, the best comparisons with the measured MDD deflections were achieved when base and subgrade materials were modeled as nonlinear cross anisotropic. In terms of pavement performance prediction, predicted rutting using a nonlinear cross-anisotropy model was matched reasonably well with measured values by generating a slightly higher compressive vertical strain from each subdivided layer. In addition, the cross-anisotropy characteristic of asphalt concrete material was introduced and applied to predict pavement performance. This results in larger rutting due to vertical strain within the asphaltic concrete layer. Thus, there is a need to take into account nonlinear cross-anisotropy characteristic of pavement materials in assessing pavement damage due to truck loadings.