A systematic review on sustainable utilization of plastic waste in asphalt: assessing environmental and health impact, performance, and economic viability.

Increasing amount of plastic waste (PW) poses a global challenge that necessitates multifaceted strategies. Repurposing PW in asphalt pavement is a sustainable strategy with extensive benefits, but there are several challenges that need to be overcome. This systematic review aims to examine three significant aspects associated with plastic-modified asphalt: environmental and health considerations, performance and technical properties, and cost.-effectiveness and economic feasibility. The environmental and health impacts of using PW in asphalt were particularly focused on the release of carcinogenic compounds and harmful fumes like polyaromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs), microplastic pollution, and climate impact. Environmental challenges and potential health risks associated with the use of PW in asphalt production were analyzed and indicated. Afterwards, the effects of different plastic types on the fatigue and rutting resistance of asphalt pavement are investigated. While many types of PWs show potential for enhancing rutting and fatigue performance, conflicting results have been observed for certain plastics. Some PW types, such as polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), low-density polyethylene (LDPE), and high-density polyethylene (HDPE), have been shown to yield inconsistent results. Lastly, factors that are recognized to have an impact on the cost-effectiveness of plastic-modified asphalt include the collection and processing costs, asphalt materials price and availability, incorporation method, and possible changes in the asphalt's lifespan. The findings of this review help researchers to identify current gaps and aid stakeholders in making informed decisions towards more environmentally friendly, high-performance, and economically viable approaches to asphalt production.