Low Temperature Study on the Behavior of Reinforced Bitumen in Asphalt via Addition of Synthesized Basalt

Abstract

Abstract In traffic engineering, one of the problems presented by slate pavement, besides being costly to repair and maintain, is the insufficient resistance of bitumen against traffic loads in low temperatures. In this study, the effect of synthesized basalt modifier has been assessed via four different tests to improve bitumen performance. Hence, the enhancement of resistance to traffic loads at low temperatures as an essential problem of asphalt superstructure in traffic engineering has been taken into account. The bending beam rheometer test was conducted at three temperatures of −6°C, −12°C, and −18°C, and the softening point and permeability index tests were performed. A Fourier transform infrared spectroscopy test was carried out to identify the structure of the modifier additives. The prepared samples of synthetic basalt-reinforced foam bitumen and synthetic basalt bitumen were examined, each having three values of 2, 4, and 6 % of reinforcement agent. The results showed that the bitumen mixture including 6 % synthetic basalt has the lowest operating temperature compared with the base counterpart having the same resistance to traffic loads at low temperatures. In addition, the temperature sensitivity of synthetic basalt-reinforced foam bitumen depressed by diminishing the modifier amount because adding the 6 % synthetic basalt to the base bitumen increased it from −0.65 to 0.91. The obtained results indicated that the achieved modified bitumen with optimal temperature sensitivity could be a good choice for employment in road construction.