A review study on utilization of waste cooking oil, eggshell, glass, and plastic in bituminous mixtures

The increasing generation of domestic waste poses significant environmental challenges, particularly in the context of disposal and resource utilization. This review critically evaluates the potential application of selected household waste materials-waste cooking oil (WCO), eggshell powder (ESP), waste plastics (WP), and waste glass (WG)-as functional additives in the bituminous binder and mixture. The study explores their roles as rejuvenators, modifiers, fillers, and partial replacements for coarse and fine aggregates. Findings indicate that WCO, when used in concentrations of 1-4%, effectively rejuvenates aged binders by enhancing workability and reducing stiffness. Incorporation of 5% ESP improves binder stiffness and resistance to thermal-induced deformations. Bitumen modified with 0.25% LDPE, 2% HDPE, and 1% PP when used in combination displays significantly enhanced adhesion and elasticity. Additionally, substituting aggregates with WG up to 10-15% demonstrates improvements in strength and durability without compromising mix integrity. The review further discusses the challenges associated with integrating these materials in road construction. The comparative analysis confirms that these waste-derived modifiers can partially or wholly replace conventional materials, contributing to both enhanced pavement performance and sustainable infrastructure development.