A 3D-FE Model for the Rutting Prediction in Geogrid Reinforced Flexible Pavements

Abstract

Permanent deformation (rutting) is an important disturbing failure on flexible road pavements. This phenomenon appears on the flexible pavement as longitudinal depressions, and it is a consequence of the degradation of materials under high traffic loading based on consolidation/densification, surface wear, plastic/shear flow, and mechanical deformation. Hence, the rutting phenomenon depends on the accumulation of permanent deformations on pavement surfaces subjected to repeated wheel loads. In recent years, several studies have confirmed that the service life of asphalt pavements can be increased by using geosynthetics between or within layers because of the improved mechanical properties. The aim of this paper is to present the results of the 3D-finite element (FE) simulations and the development of the rutting phenomenon in a traditional flexible pavement and a reinforced one, both subjected to a cyclic load. Through Abaqus/CAE software, a road section reinforced by a geogrid was analyzed and compared with a traditional road section to investigate the advantages given by the geosynthetic completely embedded at two-thirds of the asphalt concrete layer (AC) in terms of permanent deformations. The results show the capability of the proposed FE study, that uses the plasticity model of Drucker-Prager for unbound materials combined with the simple creep law to model HMA layers to predict the permanent deformation distribution.