▎ 摘　　要

Rutting in bituminous mixture is one of the most studied research problems in pavements. The increased axle loads and higher temperature form favorable condition for rutting. Efforts have been made to improve rutting resistance of bituminous mixtures using various methodologies. However, with ever increasing global temperature due to climate change, bituminous materials should be modified to adapt for such changes over the long run. One of the methodologies includes use of conductive fillers to modify bitumen. In this study, graphene was used as conductive filler for modifying bitumen to investigate the augmentation in rheological and thermal properties. Two viscosity graded bitumen (VG30 and VG40) were modified with 0.5, 1.0, 1.5, and 2.0% of graphene by weight of bitumen. The control and graphene modified bitumen were subjected to softening point test, storage stability test, frequency sweep, multiple stress creep recovery (MSCR) test, and thermal conductivity test. The isochronal curves indicated reduction in loss factor and phase angle, while increase in complex shear modulus in graphene modified bitumen compared to control binder. The difference in rheological properties between control and modified bitumen were found to be higher at higher testing temperatures. Transition from rubbery state to glassy state was observed at high temperature and high frequency loading, where decrease in phase angle and loss factor was seen. The creep-recovery curves showed higher recovery in graphene modified bitumen at different stress levels, while control bitumen depicted negative recovery with increase in stress levels. The isochronal and MSCR test indicated that an optimum level of graphene was between 1.0 and 1.5% by weight of bitumen, which can be attributed to homogeneous dispersion. Thermal conductivity of bitumen increased with the dosage of graphene as higher number of particles will increase the conducting potential. Overall the results indicated graphene addition in bitumen improved rheological and thermal properties with the potential of reducing rutting in mixtures. (C)2019 Elsevier Ltd. All rights reserved.