Modification of the Asphalt Binder with Nano-aluminum Oxide: An Alternative to Improve the Thermal Conductivity and the Rheological Properties of the Asphalt Matrix

Abstract

Abstract This article presents the results of research that aimed to develop asphalt nanocomposites (conventional asphalt binder + nano-aluminum oxide [Al2O3]) with greater thermal conductivity and better rheological/mechanical properties, at high and intermediate temperatures, when compared to a reference matrix. The end goal was to be able to recommend a range of additional nanoparticle content to the conventional binder, establishing a direction for future investigations into the healing ability of asphalt mixtures with nano-Al2O3, both in the laboratory and in service. Conventional asphalt was modified with 1 %, 2 %, 3 %, 4 %, 5 %, and 6 % of nano-Al2O3 content in relation to the mass of the binder. Tests with a conductivity meter and a dynamic shear rheometer were performed on the developed nanocomposites. Rheological parameters related to susceptibility to permanent deformation and tolerance to fatigue damage were specially analyzed. As main findings, the addition of nanoparticles increased the thermal conductivity of the binder at the rate of 0.004 W/mK/%nano, improved the rheological parameters of asphalt at high temperatures (susceptibility to permanent deformation) for any incorporation content between 1–6 %, and impaired fatigue damage tolerance (at 20°C) with percentages greater than 3 %. The main conclusion of this research is that nano-Al2O3 can increase the thermal conduction capacity of the matrix and improve the rheological performance of the conventional binder, at high and intermediate temperatures, with certain percentages of incorporation (1–3 %). Finally, for future studies with asphalt mixtures, an additional range of nano-Al2O3 in the conventional binder from 1–3 % is recommended.