Investigation of mechanical properties of stone mastic asphalt mix (SMA) modified with Nano Reduced Graphene Oxide

With the increasing use of asphalt roads, it is necessary to design and produce asphalt pavements that can withstand various damages such as rutting damage, cracking, and moisture damage. The use of nanomaterials due to their excellent and unique features in the asphalt pavement industry to improve the mechanical properties of asphalt has welcomed broad attention in recent years. This study examined the impacts of Nano Reduced Graphene Oxide (RGO) on the mechanical properties of stone mastic asphalt mixture (SMA). In this study, indirect tensile strength test, static creep test, and Pull-off adhesion test were used to investigate the effect of Nano reduced graphene oxide on the mechanical properties of SMA mixture. The pure asphalt binder was modified with three different percent of Nano RGO (0.2 %, 0.4 %, and 0.6 % by weight of bitumen used in asphalt samples in this study). The experiments performed on modified bitumen in this study show that the addition of Nano reduced graphene oxide in pure bitumen raises the viscosity, softening point, and specific gravity and reduces the ductility and penetration of pure bitumen. The mechanical tests showed that augmenting the percentage of Nano reduced graphene oxide leads to increased indirect tensile strength, pull-off adhesion resistance, accumulated strain, reduced creep stiffness, and improved moisture sensitivity in stone mastic asphalt mixture. In general, 0.6% of this nanomaterial caused more significant changes in the mechanical properties of SMA mixtures than other amounts of Nano-reduced graphene oxide. So that adding 0.6% of this additive in the asphalt mixture has increased the TSR index by 23%, increased the pull-off adhesion resistance in the wet condition by 48%, and reduced the creep stiffness by 43% compared to the control mixture.