Performance Characterisation of Asphalt Concrete Containing Waste Asphaltenes-Modified Binder and PET Fibre Using Balanced Mix Design Approach

This chapter aims to evaluate the performance of asphalt mixes modified with 12% of waste asphaltenes and polyethylene terephthalate (PET) fibres at a dosage of 0.15% using a balanced mix design approach. The research focuses on assessing the cracking resistance of the modified mixes while ensuring sufficient rutting resistance. The results demonstrate considerable improvements in the PET mixes tested at 60 °C, with a rut depth of 5.5 mm at 20,000 passes, indicating excellent rutting resistance compared to the control mix, which shows signs of moisture damage. The indirect tensile asphalt cracking test (IDEAL-CT) results show a strong impact of fibre addition in that the CTIndex at 37 °C of the fibre-modified mixes is very similar to that of the softer unmodified mixes tested at a standard temperature of 25 °C. The higher temperature is based on the modified binder PG grade and is selected because at 25 °C, the tensile strength of the modified mixtures is very high, which masks the influence of fibres. The balanced mix design approach proves valuable in understanding the effects of different modifications on asphalt mixes, providing a thorough understanding of their performance characteristics.