The Role Of Nano-Alumina Particles In Enhancing Asphalt Binder Rheological Properties

Traditional asphalt binders face significant challenges such as aging, temperature susceptibility, and fatigue cracking, which adversely impact highway maintenance and rehabilitation. Modern road networks also face emerging challenges such as increased traffic loads, climate change-induced temperature extremes, and in return, the need for more sustainable and eco-friendly materials to reduce environmental impact is essential. Aging reduces the binder's flexibility, increasing the likelihood of pavement cracking under traffic loads. Temperature susceptibility leads to rutting at high temperatures and thermal cracking in cold conditions, while fatigue cracking compromises the structural integrity of roads under repeated loading. These issues result in higher maintenance costs, reduced infrastructure durability, and potential safety risks for road users. Addressing these challenges is critical to developing sustainable, cost-effective, and safe road networks. Researchers have explored innovative solutions, including incorporating nanomaterials into modified asphalt binders alongside additives like rubbers and polymers. This study investigates the direct integration of nano-alumina into a 60/70 penetration grade asphalt binder without additional additives. Using a high-shear mixer, nano-alumina was incorporated at varying concentrations (2%, 4%, 6%, and 8% by weight). Conventional and rheological tests revealed that the nano-modified binder exhibited enhanced temperature susceptibility, improved overall viscoelastic properties, increased stiffness, better ageing resistance, and improved performance at low temperatures. For example, penetration improved up to 30% for 6% nano content and temperature susceptibility, reaching up to 35% in some contents