Performance of reclaimed asphalt pavements containing recycled waste plastics

Abstract

This paper examines the merits of using waste plastics in asphalt pavement. Waste plastics are a major global concern, and there is a need for the sustainable valorization of end-of-life plastics. Because of their characteristics as thermoplastics, treated plastics can be valuable modifiers for hot-mix asphalt (HMA) if they are compatible with the asphalt matrix. The objective of this study is to characterize the rheological properties of asphalt binder modified with linear low-density polyethylene (LLDPE) and reactive elastomeric terpolymers (RET) as compatibilizers along with polyphosphoric acid (PPA) for better dispersion in the asphalt matrix. To do so, a polymer-modified binder (PMB) was prepared by adding the above polymers to asphalt binder, and the PMB was then used to glue mineral aggregates together. Two types of mineral aggregates were used: virgin aggregates, and aggregates with 20 % reclaimed asphalt pavement (RAP). At the binder level, rheological properties were studied. At the mixture level, the IDEAL Cracking Test was used to evaluate resistance to fatigue cracking, and the Hamburg wheel-track (HWT) test was used to assess the resistance to rutting. When using virgin aggregate, the resistance to fatigue cracking was nearly the same regardless of using a polymer-modified binder or conventional binder. However, when RAP aggregate was used with a polymer-modified binder, there was a significant reduction in resistance to fatigue cracking. The HWT test results showed similar resistance to rutting after 20,000 passes for all HMA mixtures, regardless of aggregate type and asphalt modification.