Optimization of Plastic Waste for Flexible Road Construction

Bitumen is widely used in flexible pavement construction, but growing plastic waste has raised environmental concerns. This study explores the use of waste plastic bottles as a modifier in bitumen to improve pavement performance while reducing plastic pollution. Shredded plastic was added to hot bitumen in proportions of 3%, 5%, 7%, and 10% by weight. Laboratory tests including penetration, softening point, ductility, viscosity, and short-term thermal aging were conducted and compared with conventional bitumen. The results showed improved softening point and viscosity, reduced penetration, and better thermal stability in plastic-modified bitumen. The study identifies an optimum plastic content and supports the sustainable use of plastic waste in flexible pavement construction.