Enhancing Bitumen Properties through the Utilization of Waste Polyethylene Terephthalate and Tyre Rubber

Abstract

The disposal of waste accumulation has become a significant challenge in Oman due to the increasing population. Co-biodegradability issues arise from accumulating two types of non-co-biodegradable waste materials: plastic and rubber. Asphalted pavements experience various stresses resulting from high traffic density, leading to numerous problems. This study aims to investigate the impact of incorporating waste plastic and rubber on the engineering properties of bitumen. Specifically, the study examines the addition of waste tyre rubber (4% and 6%) and waste polyethylene terephthalate (PET) (4% and 6%) to bitumen with a grade of 85/100. Three tests were conducted to evaluate the physical properties of the bitumen, including softening points, penetration tests, and viscosity tests. The results demonstrate that the penetration of bitumen with the addition of 6% waste tyre rubber and PET was 9% lower compared to the 4% mixture for both waste materials. Furthermore, tyre rubber-modified bitumen exhibited higher softening points (79 °C, 2580 s) and viscosity when compared to plain bitumen (48 °C, 1800 s) and PET-modified bitumen (53 °C, 2150 s). These differences indicate that incorporating waste PET and tyre rubber improves the engineering properties of bitumen. This study highlights the importance of increasing the softening point of bitumen in Oman’s high-temperature areas.