Performance evaluation of Al₂O₃ nanoparticle-modified asphalt binder

The rheological and physical properties of asphalt binders modified with aluminium oxide (Al2O3) nanoparticles were investigated. Al2O3 nanoparticles were added to the base asphalt binder at concentrations of 3, 5, and 7 wt.%. Superpave binder tests were conducted to evaluate the characteristics of the nano-Al2O3-modified binders. Rotational viscosity tests and a dynamic shear rheometer were used to analyse the rheological and physical properties of the modified binders, and Fourier transform infrared spectroscopy technique to observe changes in the structure of modified binders compared to the original. The penetration and ductility values decreased with added Al2O3 as well as temperature susceptibility. The phase angle δ is reduced with 5 wt.% or less Al2O3 added to the binder. The complex shear modulus G* significantly increased with the addition of up to 5 wt.% Al2O3. Results recognise 5 wt.% as the optimum level. The performance of nano-Al2O3-modified binders was enhanced regarding their resistance to both thermal rutting at high temperatures and fatigue cracking at low temperatures. Furthermore, statistical analysis of penetration, softening point, complex shear modulus, and phase angle results, using both one- and two-way ANOVA tests, show a significant difference level, having remarkable impacts on the dependent variables.