Investigation of Mechanical Properties of Short- and Long-Term Aged Asphaltite Modified Asphalt Mixtures

Abstract

In this study, the effects of asphaltite and long-term aging (LTA) on the mechanical properties of hot-mix asphalt were investigated. The asphaltite entrained as filler at five different proportions into the hot-mix asphalt samples, and the obtained results were compared against the control mixtures. The pure and asphaltite-containing compacted mixtures were exposed to LTA in an oven. Marshall stability, resistance to moisture-induced damage, and resistance to crack propagation tests in accordance with the principles of elastic-plastic fracture and linear-elastic fracture mechanics were carried out on the mixtures. It was determined that the optimal proportion of asphaltite usage as filler with respect to volumetric design is 3% by weight. The test results demonstrated that asphaltite use enhances resistance against permanent deformation, moisture-induced damage, and crack propagation, especially at normal temperatures, albeit at the cost of causing the hot-mix asphalt to exhibit a more brittle behavior. The use of asphaltite would be recommended to reduce the long-term effects of aging in general, specifically on account of the results of the stability, moisture-induced damage, and fracture toughness tests.