LAUSR

Abstract The aim of the research was to evaluate the performance of Hot Mix Asphalt (HMA) and bitumen by modifying bitumen with nano materials according to Superpave™ mix design procedure. In this research, bitumen was modified by Multi-Walled Carbon Nanotube (MWCNT) and Carbon Nanotubes Doped with 50 wt% SiO2 Nanopowder (SiO2dopedCNT). Nano materials were mixed with base bitumen at contents of 1, 3 and 5% by weight. Rutting and fatigue performance of bitumen was determined. HMA is prepared with nano modified bitumen at optimum binder content (OBC). Moisture susceptibility of modified hot mix asphalt was evaluated according to Modified Lottman test procedure. Nano modified bitumens were also evaluated by scanning electron microscopy whether the modification was uniform or not. As a result, better performance was obtained by SiO2dopedCNT modification. Performance Grade (PG) of all modified bitumen was determined as PG 64-22 except MWCNT modified bitumen at the content of 1% (which was PG 58-22). OBCs were decreased by modification. All nano modified hot mix asphalt samples were determined as high resistive to moisture compared to reference sample except samples modified with SiO2dopedCNT at the content of 5%. Homogenous mixture was obtained according to scanning electron microscopy results. It was found that the agglomeration of nano materials is mostly lower than 4 μm in the mixtures.