Evaluation of dynamic properties of hot mix asphalt modified with nano-graphene

One of the methods to improve the properties of asphalt mixtures is using additives. One of the additives that have received a lot of attention in recent years is nanomaterials, which have been very popular due to their unique characteristics. In this study, the effects of nanographene on the performance characteristics of hot asphalt mixtures have been investigated. For this purpose, bitumen was modified in 0.1%, 0.3%, and 0.5% (by weight of bitumen) and by performing bitumen tests, the optimal amount of nanographene selected was 0.5%. Then, in order to evaluate the performance characteristics of the mixtures, repeated axial load tests (RLA), indirect tensile strength modulus (ITSM), and indirect tensile fatigue test (ITF) were performed. Besides, in order to evaluate the moisture sensitivity of the mixtures, indirect and compressive tensile tests were performed on the samples in both dry and wet conditions. The results showed a decrease in the final deformation, an increase in stiffness at temperatures of 5, 25, and 40 by 15, 36, and 54%, respectively. Also, in some samples, the fatigue life of modified asphalt mixtures was improved by up to 55% compared to conventional mixtures. Increasing the TSR index in the indirect tensile test indicates an improvement in the performance of the modified sample compared to conventional samples and a decrease in their sensitivity against moisture, to the extent that the indirect tensile strength of the modified sample in dry and wet conditions compared to conventional samples Increased by 23% and 38% respectively.