Environmental implications of recycled materials in pavement construction: A comprehensive review and future research directions

Abstract

The increase in global consumption of disposable products has led to a significant increase in waste generation. Life cycle assessment (LCA) serves as a methodology to evaluate the environmental impact of products and processes throughout their entire life cycle. In recent years, there has been a surge in LCA studies focused on incorporating waste and recycled materials, such as recycled concrete aggregates (RCA), reclaimed asphalt pavement (RAP), polymers, waste plastics, glass, crumb rubber, etc., into asphalt mixtures for pavement construction to enhance mechanical performance and achieve environmental benefits. This study reviewed the existing literature on LCA for these materials. In addition to energy consumption and global warming, researchers are now also focusing on other impact categories, including ozone depletion, acidification, human health particulate matter, leaching, and other factors, emphasizing their significance. Utilizing recycled materials like RAP or polymers in asphalt mixtures may reduce environmental burdens, but their storage, handling, and preparation processes may pose health risks due to water contamination and increased air pollution. The recommendations aim to offer suggestions for future research in pavement LCA.