Evaluation of eco-friendly asphalt mixtures incorporating waste plastic aggregates and additives: Magnesium, fly ash, and steel slag

This research explores the applicability of waste plastic aggregate (WPA) in the development of environmentally friendly asphalt mixtures, contributing to resource conservation, waste recycling, and the prevention of environmental issues associated with landfilling and incineration. Through experimental analysis of durability and common characteristics, the research investigates the optimal asphalt content (OAC) for practical implementation, particularly in substituting natural aggregates with waste plastic aggregates in asphalt mixture production. It examines the feasibility of producing asphalt mixtures by incorporating WPA and focuses on preventing microplastic generation using WPA in lower pavement layers. Additive materials, including Magnesium, fly ash, and steel slag powder, were used to enhance the properties of the mixtures. The experimental variation ratios in this research were assessed through a meticulous mixture design process involving the incorporation of WPA at varying contents (0%, 3%, 5%, 7%, and 10%) in both base (BB-2) and middle (MC-1) asphalt layers, enabling a comprehensive evaluation of the performance and characteristics of the resulting asphalt mixtures in comparison to control mixtures. Various tests, including wheel tracking, deformation strength, dynamic stability, crack resistance, and water resistance, are conducted to evaluate the performance of the mixtures. The findings indicate that 5% WPA can be seamlessly integrated into the asphalt mixture without external issues, and it exhibits satisfactory performance during the manufacturing process. The utilization of waste plastic fine aggregate results in non-uniform voids, while mixtures with 7% WPA fail to meet water resistance requirements. Coarse aggregates show better resistance to plastic deformation than fine aggregates, and mixtures with 5% WPA incorporating waste plastic fine aggregate demonstrate the highest resistance. Overall, this research provides valuable insights into the utilization of waste plastic aggregate in asphalt mixtures, highlighting its potential to enhance sustainability and pave the way for resource-saving practices in road construction, with the use of additive materials further improving the mixture properties.