Recent advances in the construction of sustainable asphalt roads with recycled plastic

Abstract

AbstractAlthough various polyolefins have intermittently been used for making roads since the 1980s, the recycling of plastic waste into roads raises new challenges related to the production, performance and durability of plastic‐modified asphalt. This review critically discusses the challenges of incorporating recycled plastics into bitumen/asphalt in terms of plastic selection, chemical compatibility, long‐term performance and potential contributions to fuming, microplastic pollution and contaminant leaching. Recent advances in the field are also presented and recommendations for future work to address current research and industrial gaps are suggested. Challenges related to the construction of plastic roads include the wide variability in the plastic composition and its properties after recycling, which not only affect the successful incorporation of plastic in bitumen but also impact the mechanical properties and environmental impact of the roads. The lack of representative testing procedures prevents an accurate understanding of the short‐ and long‐term performance of plastic roads in real conditions and the contribution of plastic roads to fuming and microplastic release remains unclear. However, promising laboratory‐based procedures have been developed to benchmark the release of polyaromatic hydrocarbons and volatile organic compounds, as well as microplastics, from recycled plastic‐modified asphalt against conventional polymer‐modified asphalts. Standards are still required to facilitate bitumen/asphalt modification by recycled plastics, meet the needs of bitumen/asphalt manufacturers and convince local authorities to foster the construction of plastic roads if proven to be a sustainable practice. © 2022 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.