Three-dimensional modelling of multilayered asphalt concrete pavement structures: strain responses and permanent deformation

Abstract

In any given asphalt concrete (AC) pavement structure, the permanent deformation (PD) in each AC layer has an influence and contributes differently to the total pavement rutting. The degree of influence will generally vary as a function of the AC modulus and layer thickness. Presently, most of the AC material/layer PD characterisation and analyses are based on laboratory and/or field testing in combination with stress-strain modelling under assumed circular and uniformly distributed wheel loading. In this paper, a three-dimensional finite element program, ANSYS, incorporating measured vertical tyre–pavement contact pressure (TPCP) was utilised for computing the PD of each AC layer with different variables such as the AC layer modulus, AC layer thickness, TPCP levels, vertical wheel loads, and tyre inflation pressure. A strain energy concept was also proposed for evaluating the PD rate and contribution of each AC layer. The corresponding results indicated the following: (1) the PD contribution of each AC layer varies as a function of the AC modulus as theoretically expected; (2) the intermediate AC layer significantly contributes to lateral deformation; however, both the intermediate and top AC layers significantly contribute to vertical PD; (3) the AC layer thickness and the magnitude of the lateral TPCP hardly influence the PD of the intermediate AC layer; (4) the PD influence of small light trucks can be quite substantial depending on the loading conditions and cannot be neglected in the analysis of this nature; (5) the distribution of the TPCP has a very significant influence on the PD of the top AC layer and is more pronounced as the TPCP gets more non-uniformly distributed.

Keywords:

• asphalt pavement
• measured tyre-pavement contact pressure
• three-dimensional finite element
• permanent deformation

Disclosure statement

The contents of this paper reflect the views and opinions of the authors who are responsible for the facts and accuracy of the data presented herein and do not necessarily reflect the official views or policies of any agency or institute. This paper does not constitute a standard, specification, nor is it intended for design, construction, bidding, or permit purposes. Trade names were used solely for information and not for product endorsement.

Funding

This work was supported and funded by the National Natural Science Foundation of China [51278389] and the Science and Technology Foundation of Department of Transportation of Hubei Province [2013-731-1-3].