Evaluating the Rheological Performance of Bituminous Binder Containing Nano ${\mathrm{Al}}_2{\mathrm{O}}_3$

The study reported herein investigates the effectiveness of nano aluminum trioxide (${\mathrm{Al}}_2{\mathrm{O}}_3$) as a bituminous binder modifier. The study assesses the high- and intermediate-temperature performance of bituminous binders modified with three different percentages (0.5%, 1%, and 2%) of nano ${\mathrm{Al}}_2{\mathrm{O}}_3$. A field emission scanning electron microscope was utilized to study the dispersion of nano ${\mathrm{Al}}_2{\mathrm{O}}_3$ in bituminous binder. Fourier transform infrared spectroscopy analysis was used to understand the nature of the interaction between nano ${\mathrm{Al}}_2{\mathrm{O}}_3$ particles and bituminous binder. Different rheological approaches, like the Superpave rutting parameter, multiple stress creep and recovery test, and time-temperature sweep, were used to study the high-temperature performance of nano ${\mathrm{Al}}_2{\mathrm{O}}_3$–modified bituminous binders. All the methods undertaken in the current study to evaluate rutting susceptibility showed that nano ${\mathrm{Al}}_2{\mathrm{O}}_3$ showed modified binders had a very low propensity to accumulate permanent deformation. Fatigue performance evaluated using the Linear Amplitude Sweep test showed that the incorporation of nano ${\mathrm{Al}}_2{\mathrm{O}}_3$ enhanced fatigue performance. Nano ${\mathrm{Al}}_2{\mathrm{O}}_3$–modified bituminous binders were found to be storage stable as revealed by the storage stability test. The high-temperature thermal stability of the bituminous binders measured using thermogravimetric analysis showed an improvement after nano ${\mathrm{Al}}_2{\mathrm{O}}_3$ incorporation.