Investigating the effects of nano Al<sub>2</sub>O<sub>3</sub> on high and intermediate temperature performance properties of asphalt binder
Faheem Sadiq Bhat, Mohammad Shafi Mir
Abstract
The present study explores the use of nano Al2O3 as a potential asphalt binder modifier. The study investigates the effects of different concentrations (0%,0.5%,1% and 2% by weight of the asphalt binder) of nano Al2O3 on various properties of the asphalt binders. XRD analysis is used to study the amorphous/crystalline nature of the base asphalt binder and nano Al2O3 modified asphalt binder. The influence of different temperatures and strain rates on the viscosity of the asphalt binder is evaluated. It was seen that the asphalt binder showed a shift from Newtonian behaviour to non-Newtonian behaviour upon the addition of nano Al2O3. The rutting evaluation of the asphalt binders was carried out by utilising different approaches like Superpave rutting parameter, multiple stress creep and recovery test, zero shear viscosity, and creep test. Furthermore, intermediate-temperature performance and aging resistivity of the modified asphalt binders was also evaluated. Results showed that the addition of nano Al2O3 enhances the stiffness of the asphalt binder and improves its recovery abilities. The modified asphalt binder was found to perform well under varying stresses and sustained loading and hence showed improved permanent deformation characteristics. Fatigue performance was evaluated utilising Superpave fatigue parameter and time sweep tests, and the nano Al2O3 modified asphalt binders showed improved fatigue life. The addition of nano Al2O3 also leads to an improvement in the aging resistance of the asphalt binder. The study shows an overall improvement in high temperature, intermediate temperature, and aging resistance of the asphalt binders using nano Al2O3 as an asphalt binder modifier.