Performance Optimization Approach of Polymer-Modified Asphalt Mixtures with PET and PE Waste

Road infrastructure sustainability and pavement performance may be increased by using waste materials like polyethylene terephthalate (PET) and polyethylene waste (PE waste) in polymer-modified asphalt mixtures. As seen by a more pronounced rise in the softening point, which exceeds 110 °C with 8% PE waste, PET was found to improve the tensile strength, resistance to cracking, and thermal stability of asphalt mixes. PE waste also increases ductility up to 4% PE waste, beyond which the combination becomes more brittle, and dramatically decreases penetration, strengthening the asphalt's resistance to deformation. Additionally, bitumen treated with PE waste is more workable than asphalt without PET, even though bitumen treated with PE waste had a viscosity of up to 4500 Pa. Complex shear modules decreased as the PE waste and PET content increased. PET, on the other hand, increases the binder's overall stiffness, elasticity, and tensile strength. Nevertheless, when PET content rises, ductility steadily decreases. Previous studies concentrated on the effects of each component separately, and this paper fills this knowledge gap by investigating the combined effects of PET and PE waste. The results indicate that the highest compressive strength (7.5 MPa) was obtained with 6% PE + 2% PET, while the highest tensile strength (1.40 MPa) was achieved with a balanced mix of 4% PE waste + 4% PET. Additionally, the viscosity of asphalt is increased by PET and PE waste, enhancing its performance at high temperatures. These findings demonstrate how combining PET and PE waste improves the mechanical and thermal characteristics of asphalt, providing a balance between stiffness and flexibility, a crucial feature for durable road materials under a variety of circumstances.