Rutting performance evaluation of asphalt mix with different types of geosynthetics using MMLS3

This paper presents an evaluation of the rutting performance of geosynthetics in asphalt pavements. The rutting performance of both a fibreglass geogrid and a sheet reinforcement material were evaluated using the third-scale model mobile loading simulator (MMLS3). The surface profile of each type of reinforced slab (and a control slab) was monitored and compared. To investigate movement of the mixtures caused by MMLS3 loading as well as the interfaces of the reinforcements in the asphalt slabs, trench cuts were made once the MMLS3 rutting tests were complete. The results demonstrated that reinforcement can reduce downward ruts and that different types of reinforcement exhibited different shear flow behaviour. The geogrid-reinforced slabs showed the shallowest ruts and the most shear flow resistance due to the tension resistance of the geogrid. They exhibited confinement and increased friction due to the aggregate particles that were locked in the geogrid openings. The sheet-reinforced slabs exhibited the highest shear flow humps due to the lack of interlocking and bonding strength at the rutting test temperature. In addition, the geogrid openings, which were supposed to provide interlocking and anchoring, in fact generated a relatively high volume of voids at the interface between lifts. Further research is needed to evaluate the effects of high air voids at the lift interface on pavement performance.