Geogrid Reinforcement in the Treated Base Layer of Flexible Pavements

Abstract

AbstractThis paper aims to tackle the issue of enhancing the performance of flexible pavements. Enhanced performance is associated with the pavement's ability to withstand and resist the heavy traffic loads. In this study, geogrids are placed at different positions in the treated base (binder course) layer of the flexible pavement structure and compared to a control unreinforced pavement. The methodology consists of two phases, the first phase is an experimental work program, and the second is a pavement numerical modeling. The experimental work entails lab material testing and full-scale testing. Lab material testing was conducted to determine the physical and mechanical properties of the materials used, while full-scale testing was conducted to represent the pavement's behavior. A control large-scale model was subjected to dynamic traffic simulated loading. In the second phase, a numerical model was created, using finite element modeling software that included the reinforcing geogrid. Using this numerical model, several iterations and trials were made to investigate the effect of the geogrids’ various locations in the treated base layer; hence determine its optimum position for enhanced pavement performance. The results indicated that geogrid reinforcement in the treated base layer has significantly enhanced performance, in terms of reduced permanent deformation in the AC surface layer as well as better distribution of induced stresses throughout the flexible pavement structure. The optimum location for the geogrid in the binder course layer was determined to be at the middle of the binder course. Results showed that geogrids provide better enhanced performance of the pavement if installed in the treated base layer than that if it is installed in the untreated base layer.