Mechanical and durability characteristics of nanoalumina modified asphalt mixtures for sustainable pavement applications

Moisture damage is a major factor affecting the durability of hot mix asphalt. This study aimed to investigate the effect of alumina nanoparticles on the physical, mechanical, and moisture-resistant properties of asphalt mixes. Alumina nanoparticles are added to AC (40-50) asphalt binder at 2%, 4%, and 6% of the binder weight. The experimental program included tests of physical properties, Marshall properties, indirect tensile strength, compressive strength, tensile strength ratio, and residual strength index. The results showed that alumina nanoparticles improved the binder properties by reducing penetration and increasing the softening point and flash point. Marshall stability is increased by up to 25.41%, while the modified mixes showed a decrease in air voids and an increase in bulk density. Furthermore, the values for indirect tensile strength, compressive strength, tensile strength ratio, and residual strength index are significantly improved, indicating enhanced moisture resistance and increased bond strength between the binder and aggregate. Optimal performance is achieved using 4% alumina nanoparticles, providing the best balance between mechanical properties and moisture resistance. These results demonstrate the potential of alumina nanoparticles as an effective modifier for improving the durability of asphalt mixtures.