Utilization of fly ash and glass powder as fillers in steel slag asphalt mixtures

Abstract

In the developing countries, the management of industrial wastes such as fly ash, glass powder, and steel slag has become a severe problem. If the fly ash, glass powder, and steel slag can be utilized for road construction, this problem will be solved. The present study investigates the effects of fly ash (FA) and glass powder (GP) as filler (in lieu of stone dust) and coarse steel slag aggregate (in lieu of coarse natural stone aggregate), on the performance of asphalt mixes for road construction. Based on Marshall Mix design, the optimum amount of FA and GP is 60 % and 30 %, respectively, in place of stone dust. Control mix and steel slag mixes made with FA and GP are subjected to moisture sensitivity, resilient modulus, and wheel tracking tests. The inclusion of FA improves the moisture damage resistance of steel slag mixture, while the GP shows reduced moisture damage resistance due to silica content. Nevertheless, it satisfies the moisture criteria as per standards. Besides, both FA and GP improve the stiffness and show reduced rutting depth by 39.33 % and 22.3 %, respectively, in steel slag mixture. The FA exhibits better performances than the GP. Moreover, cost analysis reveals that asphalt mixes using FA, GP, and steel slag aggregate decrease the construction and life cycle costs compared to the control mix. As a whole, FA, GP, and steel slag aggregate can be used as alternative materials in asphalt mixes for road construction.