Characterization of Sustainable Asphalt Mixtures Containing High Reclaimed Asphalt and Steel Slag

Policymakers are implementing the transition to a circular model in all economic sectors to drastically mitigate the effects of climate change. In this regard, the producers of paving products should promote the reuse and recycling of solid waste in the design of sustainable asphalt materials. This study evaluated the performance-based properties of three highly recycled mixtures for wearing courses of asphalt pavements containing steel slag and varying amounts (25, 40, and 50%) of fractionated reclaimed asphalt (RA). In addition, the mixtures incorporated a warm mix asphalt (WMA) organic additive to lower production temperatures compared to a reference hot mix asphalt (HMA). Based on the experimental results, the warm recycled asphalt mixtures show equivalent or better performance compared to HMA in terms of moisture susceptibility, stiffness, rutting and fracture resistance, and surface macrotexture. Therefore, the combined incorporation of RA and steel slag with WMA was proven to be an effective option in designing environmentally friendly and high-performance wearing course mixtures.