Document Type : Original Article
Department of Civil Engineering, Urmia University, Urmia, Iran.
The performance of asphalt pavements against environmental factors such as moisture is important. Many failures are caused by the direct flow of water into the pavement and the weakening of the bond between bitumen and aggregates. Therefore, the purpose of this study was to investigate the effect of anti-stripping nano-materials and Iranian Gilsonite on the moisture susceptibility of asphalt mixtures, and in this research, hot-mix asphalt is investigated. To achieve this goal, the calcined aggregates, bitumen 60-70, and two additives of mineral pitch and Zycosil are used. The mineral pitch was mixed with bitumen at 3, 6 and 9% levels by weight of bitumen and Zycosil was mixed at 0.15% by weight of bitumen for each asphalt specimen. The level of bitumen used in samples is considered to be the same with the optimum bitumen of the control sample. Then, the diagrams of tests conducted on the samples were plotted. These tests, which were used to study the effect of these materials on the adhesion and strength of asphalt mixtures, include indirect tensile test, resilient modulus and Marshall stability. The results from the experiments show that the mineral pitch and Zycosil improve the performance of hot-mix asphalt.