Laboratory evaluation of asphalt mixtures reinforced with aramid fibres coated with bituminous oils

Adding additives such as fibres to asphalt mixtures is believed to improve the overall performance of hot mix asphalt (HMA). Unlike previous studies, this research investigates the performance of HMA modified with oil-coated aramid fibers, exploring its potential to enhance rutting resistance, fatigue behavior, and low-temperature cracking. The fibers were utilized at various dosages (110, 138, and 164 g/tonne) and lengths (13, 20, and 25 mm). Comprehensive evaluations were conducted using the Hamburg wheel tracking device, four-point bending fatigue test, and thermal stress restrained specimen test to assess the impact of these modifications on HMA properties. The results found that 25 mm long aramid fibres, at all dosages, improved the rutting resistance by up to 65% compared to the control mixture. However, the fatigue behaviour and low-temperature cracking resistance were not as good as the rutting performance. Therefore, and based on this study, it was concluded that the addition of the newly developed bituminous oil-coated aramid fibres has no positive impact as a reinforcement of the asphalt mixture.