Durability of Recycled Cellulose and Ground Granulated Blast-Furnace Slag–Hydrated Lime Modified Cold Mix Asphalt Mixtures

This study evaluates the long-term durability of Cold Mix Asphalt (CMA) mixtures modified with Recycled Cellulose Pellets (RCP), and a combination of Ground Granulated Blast-furnace Slag (GGBS) with Calcium Hydroxide, together referred as GC, as a sustainable filler replacement. The research investigates the effects of long-term ageing and water sensitivity on stiffness, rutting, and fatigue performance. CMA specimens were assessed under simulated in-service ageing, with comparisons made to initial curing conditions at 20°C and 40°C. RCP was incorporated to enhance moisture regulation and flexibility, while GC aimed to improve stiffness, cohesion, and early-life strength. Results demonstrated that long-term ageing generally improved stiffness and rutting resistance, particularly in GC-modified mixtures, while RCP-modified mixtures showed enhanced fatigue resistance and flexibility. Although performance trade-offs were observed, the combined use of RCP and GC achieved a balanced improvement in durability. These findings provide valuable insight into optimising CMA design for enhanced performance and sustainability across varying environmental conditions.