Environmental assessment of warm mix asphalt incorporating steel slag and high reclaimed asphalt for wearing courses: a case study
Panos Georgiou, Andreas Loizos
Abstract
This study quantifies the potential environmental benefits associated with the incorporation of industrial by-products and recycled materials combined with warm mix asphalt (WMA) additives in wearing course mixtures for asphalt pavement construction. An electric arc furnace (EAF) steel slag-based mix and three recycled mixtures incorporating steel slag and fractionated reclaimed asphalt (RA) of varying contents (i.e. 25, 40, and 50%) were analyzed comparatively to reference hot mix asphalt (HMA) using the ‘cradle-to-gate’ approach. The results of this study indicated that the warm asphalt mixture incorporating steel slag and 50% RA is the most environmentally friendly alternative. The greatest environmental benefits result from the combined use of steel slag and reclaimed asphalt, which is attributed to lesser demands for raw material extraction, bitumen production, and resource supply. On the contrary, the contribution of lowering mixtures’ production temperature by 30°C is minimal.