Recycled plastics in asphalt pavement: life cycle assessment and environmental impact implications

Abstract

[EMBARGOED UNTIL 8/1/2023] This study is focused on exploring how the recycled plastics, when being used as an additive in the production of asphalt pavement, could impact the environment from a life cycle assessment perspective. The plastics modified asphalt and life cycle assessment system are first reviewed. The incorporation of waste plastics into asphalt pavement is an emerging recycling strategy that could greatly reduce the release of plastics into the environment with concurrent asphalt pavement performance and economy benefits. Data from Environmental footprints were collected and used in a comparative life cycle assessment study on two different scenarios. The analyses of environmental impacts of these different scenarios were conducted with the Open LCA software model calculation. Overall, the results indicate that regular recycled plastics (polyethylene) as additive for asphalt pavement has environmental advantages when compared to recycled PET (polyethylene terephthalate). Meanwhile, the recycling plastics process is more beneficial to the environment than conventional landfilling disposal. Additional study is needed to develop a comprehensive understanding of the pros and cons regarding the plastics-modified asphalt (PMA) by collecting primary data on the PMA performance under different application settings, assessing the sorting and pre-processing approaches of waste plastics, and monitoring its long-term stability and environmental impacts.