Evaluation of mechanical and performance characteristics of bitumen mixture using waste septage ash as partial substitute

Abstract The aim of this research is to investigate the potential application of septage ash (SA) as a partial substitute for conventional fillers in Bitumen mixes. The study’s purpose was to evaluate the mechanical and performance characteristics of Bitumen mixes by incorporating varying amounts of SA into the filler. To achieve this, bitumen mix samples were prepared with different concentrations of SA (5, 10, 15, and 20% of the filler weight). The study’s initial focus was on analyzing the physical properties of the samples and determining the fundamental parameters of tiny crystallites using X-ray diffraction and specific surface area. Additionally, the strength, stiffness, resistance to velocity, temperature effects, and impact of water on the mixture were carefully evaluated by conducting Marshall stability tests, indirect tensile strength, Cantabro tests, Freezing and Thawing (F&T) tests, and Moisture susceptibility tests to determine their durability in the presence of water. The findings of this study indicate that incorporating SA improved the strength by 32%, reduced fine loss by 23% at an optimal 5.35% bitumen content, and increased moisture sensitivity by 15%. Overall, the experimental results suggest that waste SA can be used as a sustainable solution to improve the mechanical performance of the surface.