Evaluating the rheological properties of bitumen and mechanical properties of asphalt mixtures modified with copper nano oxide

The growth of the transportation network has led to a special need to the life cycle cost analysis and increase the lifespan of asphalt mixtures. There are several ways to improve the performance of asphalt mixtures, one of which is bitumen modification using modifiers. In recent years, with the invention and expansion of the production of nanomaterials, special attention has been paid to the use of nanomaterials to improve the rheological properties of bitumen. Accordingly, this study evaluates the effect of copper nanooxide on the rheological behavior of bitumen and the mechanical properties of the asphalt mixture. Therefore, the dynamic shear rheometer is used to determine the specifications of bitumens at medium and high temperatures, as well as fatigue and dynamic creep tests to investigate the performance of asphalt mixtures against fatigue cracking and rutting. The results of bitumen rheological experiments show that the use of copper nanooxide at 1 and 2 percent by weight of bitumen improves the rutting parameter in unaged and short-term aged bitumen from 49-343 and 57-257 percent, respectively, and also improves the fatigue parameter in long-term aged bitumen from 11-40 percent. The results of fatigue tests show that the fatigue life of samples containing 1 and 2 percent of this additive at 5 and 20 °C will improve by 9-16 percent and 6-31 percent, respectively. Also, the results of the rutting potential show that the use of 1 and 2 percent of nanooxide has reduced the permanent deformation change of 13-35 and 18-18 percent, respectively.