Performance improvement of asphalt concretes using steel slag as a replacement material

The increased proportion of traffic volumes on roads is often the cause of distress to the pavement structure. The use of strong and durable steel slag (S) as an aggregate material in asphalt concrete can enhance the load-bearing capacity while at the same time conserving natural resources, resulting in a sustainable asphalt pavement system. This research evaluated the feasibility of using S to replace natural limestone (L) at various aggregate sizes in asphalt concrete. The measured performance of the L-S asphalt concretes was compared with that of L asphalt concretes and granite (G) asphalt concretes. Two types of asphalt cements, Penetration Grade AC60/70 and polymer-modified asphalt (PMA), were utilized in this research project. The mix proportions were prepared by separating each original aggregate (S, L, and G) into four bins, Bin 1 (<4.75 mm), Bin 2 (<12.50 mm), Bin 3 (<19.00 mm), and Bin 4 (