Behavior of a Warm Mix Asphalt Containing a Blast Furnace Slag

Abstract

Currently, many studies seek to find materials that are friendlier towards the environment. Warm mix asphalt (WMA) technology helps to decrease manufacturing temperature in traditional hot mix asphalts (HMA), which reduces emissions that are detrimental to the environment. For the case of asphalt pavements, WMA technology, which uses recycled materials such as blast furnace slag (BFS), this could be an interesting alternative technique. Reutilizing these types of industrial waste materials for roadway project constructions could help to minimize negative impacts on the environment. In this study, the coarse fraction of natural aggregate in a control HMA was replaced with BFS. Additionally, a chemical additive was used to lower mixing temperature by 30 °C, and thus manufacture WMA. Marshall, indirect tensile strength, resilient modulus and permanent deformation tests were carried out. This additive helps to reduce air void content, reduces mixing and compacting temperatures and increases asphalt stiffness. Studied WMA that has a 12.5% substitution of coarse natural aggregate fraction with BFS, results in a significant increase in stiffness (under monotonic and cyclic loads), as well as an increase in resistance to moisture damage and to permanent deformations, when compared to control HMA.