Enhancement of Low Temperature Crack Resistance of Warm Mix Asphalt With Plastic Waste Derived Additive Synthesised by Co-Pyrolysis Method

Abstract

This study investigated the effect of char (C) and wax (W) products obtained by co-pyrolysis of polyethylene terephthalate (PET) and high-density polyethylene (PE) type waste plastics on the low temperature performance of warm mix asphalt (WMA). PETPE-modified bitumen were prepared by adding various dosages of co-pyrolytic char/wax to virgin bitumen. Sasobit (R) was preferred as the reference WMA additive. Bending Beam Rheometer test results indicated that bitumen exhibited more flexible behaviour at low temperature with the addition of PETPE-C(6%)-W(6%). Thermal Stress Restrained Specimen Test results showed that WMA-P (PETPE-C(6%)-W(6%)) fractured at 3.10 degrees C lower than hot mix asphalt (HMA) and 4.01 degrees C lower than WMA-S (Sasobit (R) 3%), respectively. On the other hand, fracture stress of WMA-P was found to be 28% and 4.5% higher than HMA and WMA-S, respectively. Furthermore, Dynamic Shear Rheometer, Marshall stability and Hamburg Wheel Tracking test results demonstrated that the addition of PETPE-C(6%)-W(6%) did not compromise the high temperature performance of bitumen and asphalt mixture. Based on the economic analysis, pyrolytic additive cost was 0.68 $/kg, which equalised the production costs of WMA-P and HMA. WMA-S was also produced at a 4.4% higher cost than HMA. Consequently, PETPE-C(6%)-W(6%) has an improving effect on the low temperature performance of WMA.