Laboratory performance assessment of low temperature asphalt mixtures with high recycled materials contents

Systematic striving for replacing the 'end-of-life' concept with the circular economy concept in production processes is acknowledged as a pivotal strategy for advancing sustainability. Material intensive industries, including the asphalt paving industry, need to implement this concept towards the development and use of more circular products. This study investigates the potential to valorize solid waste materials, namely reclaimed asphalt (RA) and electric arc furnace (EAF) steel slag, in designing warm mix asphalt (WMA) mixtures for surface courses of asphalt pavements. Highly recycled mixtures were designed and laboratory evaluated in comparison with a reference hot mix asphalt (HMA). Performance properties evaluated included ravelling resistance, stiffness modulus, rutting and fracture resistance as well as surface macrotexture. The results indicated that the warm recycled asphalt mixtures show similar or even better performance compared to HMA. Hence, it can be concluded that the reclaimed asphalt and steel slag can be valorized towards developing resource-efficient and adequate performance (both structural and functional) asphalt mixtures for surface courses.