Marshall stability and flow tests for asphalt concrete containing electric arc furnace dust waste with high ZnO contents from the steel making process

Abstract

Metallurgical industries worldwide produce many hazardous wastes with terrible consequences for the environment. In this research, Electric Arc Furnace Dust (EAFD) has been mixed in asphalt concrete. EAFD is a hazardous waste containing heavy metals. EAFD modified asphalt was fabricated by mixing asphalt binder 60/70 with in 1, 5, 10 and 20 wt%. Asphalt concrete samples were fabricated with EAFD modified asphalt and mineral aggregates with 0.0 (neat asphalt), 10, and 20 wt% of EAFD. Marshall stability tests were used to evaluate stability, flow, stiffness, bulk specific gravity, maximum theoretical gravity, density, air voids percentage, voids in mineral aggregate, and voids filled with binder. The optimum asphalt content for mixtures with 10 and 20 wt% of EAFD was found at 6.0 and 5.45 wt%, respectively, while for the mix without EAFD the optimum asphalt content was at 5.61 wt%. Stability, stiffness, bulk specific gravity, and air voids contents, increased with the addition of EAFD. Maximum theoretical gravity and voids filled with binder decreased with the addition of EAFD content. Voids in mineral aggregates increased and then decreased with the increase of EAFD content. Flow and density decreased and then increased with the addition of EAFD content. MANOVA analysis was conducted to study the effect of each factor. All data was adjusted, and the corresponding model equations are presented and can be easily applied in industry.