Marshal Characteristics of Hot Mix Asphalt Concrete Modified with Steel Rolling Furnace Dust (SRFD)

Abstract

The study aimed to enhance asphaltic concrete properties by utilizing Katsina Steel Rolling Furnace Dust (SRFD) waste, estimated at 15-20 kg per ton of produced steel, as an additive. SRFD was incorporated into the asphalt mix at varying concentrations (0%, 2%, 4%, 8%, and 10%) by volume of binder. Optimal bitumen content was established at 5.4%, meeting the General Specification of Nigeria Roads and Bridges, 2016. Properties like stability, flow, VMA, VFB, and Pa fell within the specified range. The modified asphalt, containing SRFD, exhibited improved stability (6.61kN compared to 5.4kN in the control asphalt) and a flow of 3.9mm. This alteration led to increased bulk density, suggesting potential structural reinforcement against road pavement distress caused by traffic loads. Results from the one-way ANOVA test indicated that SRFD didn't significantly impact stability, flow, or % air voids (p-values > 0.05 and F cal. < F crit.). However, SRFD did play a significant role in unit weight, VMA, and VFB variance. Marshal Quotient values were determined for different SRFD-modified asphalt mixes, with the highest value of 2.55 indicating enhanced stability and reduced flow, potentially offering high resistance to rutting. Analysing SEM ImageJ data revealed that SRFD-modified HMA exhibited a greater spread in particle distances, with Particle Mean length and area measuring 7,825.87 micrometres and 964,775.7 sq. micrometre, respectively, and an S.D. of 2,615.615 micrometre. In contrast, the control HMA showed closer particle distance deviation, with Particle Mean length and area of 235.659 micrometre and 259.09 sq. micrometres, respectively, and an S.D. of 234.2 micrometre