Evaluation the Effect of Carbon Nanotube on the Rheological and Mechanical Properties of Bitumen and Hot Mix Asphalt (HMA)

Abstract

The technical characteristics of modified bitumen and asphalt have provided many study opportunities around the world. This article has assessed the effects of adding the Nanomaterial on the rheological specifications of bitumen by adding carbon nanotubes to bitumen and it also has evaluated the physical characteristics and bulk parameters of the surface (Topeka) layer of asphalt concrete sample by conducting Marshall Tests. In this regard, the technical characteristics of bitumen such as penetration grade, softening point, viscosity and thermal sensitivity were tested by adding carbon nanotubes with the amounts of 0.25, 0.50, 1 and 1.5 percent by weight of bitumen. The results show that adding carbon nanotube to the bitumen has been accompanied with a reduction in the penetration grade and an increase in softness of the bitumen, which improves the specifications of bitumen and therefore reduces asphalt tracking at high temperature. Following, the asphalt samples reinforced with carbon nanotubes evaluated for conducting Marshall Test. The results showed that the additive alters the Marshall Test parameters such as increasing the strength and decreasing the flow. Meanwhile, the specific gravity of asphalt mixture was increased and the void space percent of the aggregates was relatively decreased. Moreover, the void space of the asphalt mixture and the void space percent filled with bitumen were relatively increased. Economic analysis was evaluated for a 3-way path. Finally, according to the results and analysis of the Nanomaterial on the Nano specifications of bitumen and asphalt, technically, the results strongly suggest the use of carbon nanotubes. Although economically, the use of carbon nanotubes is limited.