Eco-friendly paving materials using waste PET and reclaimed asphalt pavement

Abstract

Waste polyethylene terephthalate (PET) and reclaimed asphalt pavement (RAP) represent two categories of waste materials that are currently enduring major recycling efforts around the world. This study proposes a method to incorporate PET-based additives into asphalt mixtures containing RAP. Waste PET was chemically treated using an aminolysis process to synthesise PET-based additives. The effect of the additives on asphalt binder was then characterised through molecular dynamic simulation (MDS) which indicated that the additives increase the intermolecular interaction within the asphalt binder molecules. Subsequently, binders modified with PET additives were used to prepare mixtures containing RAP at various percentages and tested through conventional rheological tests, such as Marshall Stability tests and Indirect Tensile Stiffness Modulus (ITSM) tests. Mixtures with 2% of PET additives and RAP showed improved stability and Marshall quotient values, demonstrating better resistance to permanent deformation. It was also observed that the PET additives have the substantial effect to reduce the ageing effect of mixtures containing RAP, thereby improving the longevity and service life of pavement mixtures. Overall, the results indicated that the usage of such PET derived additives can have a significant positive effect in improving the performance of asphalt mixtures containing RAP.