Effective utilization of waste cement concrete dust in bituminous concrete

This study compared the suitability of waste cement concrete dust (CD) with conventional hydrated lime (HL) as filler in bituminous concrete. Bituminous mixes containing both fillers at different proportions were designed, and their performance was studied using Marshall quotient, indirect tensile strength, tensile strength ratio (TSR), passive and active adhesion, and cantabro tests. The cost of various mixes and their greenhouse gas (GHG) emission was also compared. Finally, the optimum filler content for both mixes was determined. Mixes containing CD displayed rutting, cracking, and ravelling resistance similar to conventional mixes. CD offered improved affinity towards bitumen and ensured excellent moisture resistance (TSR > 80%). The use of CD marginally lowered the cost by around 3-8%, and reduced the GHG emissions by more than 50% as compared to the traditional mix (4% HL). Overall, the application of CD ensures satisfactory engineering performance at a relatively lower cost and GHG emissions.