Strength Properties Model of Modified Hot Mix Asphalt

Abstract

Researchers have extensively investigated the use of various materials and industrial wastes as modifiers and additives in concrete and hot mix asphalt production. Reusing and recycling industrial wastes has become more appealing, steering away from their disposal in landfills and dumpsites. This particular study aimed to enhance asphaltic concrete properties by incorporating Katsina Steel Rolling Furnace Dust (SRFD), a waste product estimated at 15-20 kg per ton of steel produced, as an additive. The SRFD was introduced into the asphalt mix at different concentrations (0%, 2%, 4%, 8%, and 10%) relative to the volume of binder. The study found the optimal bitumen content to be 5.4%, meeting the General Specification of Nigeria Roads and Bridges, 2016. Key properties such as stability, flow, VMA (voids in mineral aggregate), VFB (voids filled with bitumen), and Pa (air voids) fell within specified ranges. Notably, the modified asphalt with SRFD exhibited improved stability (6.61kN compared to 5.4kN in the control asphalt) and a flow of 3.9mm. This change suggested increased bulk density, potentially reinforcing road pavement against damage from traffic loads. Statistical analysis using one-way ANOVA indicated that SRFD did not significantly impact stability, flow, and percentage of air voids (P-values were 0.517292, 0.06201, and 0.22976, respectively, with F-calculated values lower than F-critical values). However, for unit weight, VMA, and VFB, SRFD did have a significant role in the variance of the measured properties. Regression analysis is used to develop a relationship that could be applied in similar circumstance. The models exhibited good prediction capacity with coefficient of determination (R2 values) within the range of 76% to 99%.