Cold Bitumen Emulsion Mixtures with Waste Glass: A Laboratory-Driven Investigation into Performance

Global road development accelerates environmental harm, resource depletion, and fossil fuel consumption due to conventional aggregate and hot mix asphalt (HMA) use. To combat this, sustainable pavement construction is vital. cold bitumen emulsion mixtures (CBEMs), a type of cold mix asphalt (CMA), offer a sustainable path forward. Incorporating waste materials as fine aggregates in cold mix asphalt addresses waste issues and flexible pavement development. Our research pioneers using crushed waste glass (WG) as a fine aggregate substitute in CBEM's binder layer, emphasizing unique microstructural analysis to uncover strength improvement mechanisms not explored before in binder layer gradation. This study replaces virgin fine aggregate with WG at varying percentages (0% to 100%, in 20% increments) and evaluated mechanical performance, including Marshall stability/flow, indirect tensile strength (ITS), resilient modulus (ITSM), dynamic modulus, flow number, fatigue life, and durability (retained Marshall stability). CBEM-WG mixes with around 60% WG content exhibited mechanical performance comparable to normal CBEM (NCBEM)/conventional HMA and showed improved performance beyond 60% dosage and maximum at 100% WG content. Moisture damage resistance decreases with increasing WG content but remains comparable to HMA.