Marshal Properties Assessment of Hot Mix Asphal Containing Katsina Steel Rolling Furnace Dust as an Additive

Abstract

Significant investments have been directed towards road infrastructure development, resulting in a vast network spanning approximately 194,000 kilometers. Responsibility for this network is divided among different government levels, with the Federal Government overseeing 17%, State Governments 16%, and local Governments 67% (Federal Ministry of Works Nigeria, 2013). In the steel industry, by-products like mill scale and oily sludge are generated during the cooling and rolling processes, with an estimated global production of nearly 5 million tons. The European steel industry alone produces around 500,000 tons annually, with over 30% of this remaining unutilized (Dana et al., 2017). Research incorporating Steel Dust Residue (SRFD) as an additive in asphalt mixes revealed promising results. Optimal bitumen content was identified at 5.4%, meeting the specified requirements outlined in the General Specification of Nigeria Roads and Bridges, 2016. This modified asphalt showcased improved stability (6.61kN versus 5.4kN in control asphalt) and exhibited desirable flow properties (3.9mm). XRF analysis identified the elemental composition of the steel dust used in the research, primarily comprising ferric oxide (Fe2O3 = 31%) and zinc oxide (ZnO = 28%). Experimental findings indicated that Marshal stability, unit weight, voids filled with bitumen (VFB), and stiffness initially increased and then decreased with higher SRFD content in asphalt mixtures. Notably, a 4% SRFD content by volume of binder met the specified Marshal properties for asphalt mixtures.