Optimization and characterization of lime and GGBS treated fly ash for sustainable road pavement applications

The increasing consumption of natural aggregates in road construction depletes limited resources and exacerbates environmental degradation, while industrial by-products like fly ash accumulate in landfills, posing health risks and straining land use. This study investigates the potential of utilizing fly ash in road construction, stabilized with lime and Ground Granulated Blast Furnace Slag (GGBS), to address these challenges. Response Surface Methodology (RSM) is employed to optimize mix proportions, with laboratory tests validating the improved strength and durability of treated fly ash. The optimal mix—comprising 88% fly ash, 3% lime, and 9% GGBS—meets the strength requirements for base layer applications. Spectroscopic analysis confirms gel formation, while Thermogravimetric Analysis (TGA) reveals substantial weight loss due to hydration products, indicating successful stabilization. The findings demonstrate the effectiveness of RSM in optimizing sustainable material compositions and highlight the potential of fly ash-based materials to replace natural aggregates, promoting resource conservation, environmental sustainability, and improved public health.