Effects of the properties of geogrids on reinforced asphalt pavements

In the late 1970's and early 1980's, research in reinforced asphalt pavements was revived from earlier failed attempts with the introduction of high strength plastic reinforcements termed "geogrids". Since then, many more grids have been introduced into the market. These grids, made of polyester, polyethylene, polypropylene, and fibreglass, are produced in a wide range of strengths and configurations. With this large influx of new grids, engineers are faced with the increasing problem of "when to use the grids, which one to use, and how to use it".Therefore, this thesis is based primarily on addressing some of these questions by evaluating a few grids currently available and determining which characteristics must be considered in their selection and use. Similarly, the problem of evaluating reinforced asphalt concrete slabs in the laboratory has been addressed as it was found that standard testing methods are non-existent. Finally, new compaction equipment producing high quality asphalt is introduced for the compaction of both unreinforced and reinforced asphalt.The research carried out in this thesis identified the most important parameters affecting the reinforcing mechanisms provided by geogrids. Specifically, it quantifies the relationship between the geometry of the grid and the interlock mechanism. Also, compaction procedures and installation methods have been found to play a major role in the performance of reinforced asphalt pavements.