Influence of the production temperature on the optimization process of asphalt mixes prepared with steel slag aggregates only

Abstract

This paper presents a comprehensive research aimed at evaluating the feasibility of preparing bituminous mixes using slag aggregates only (EAF slag and LF slag from electric steelmaking), i.e. without any natural aggregate. Here, the second step of the experimental study, currently in progress, is presented, focusing on investigating possible countermeasures to the issues related to a reduced compactability of steel slag materials, such has been evidenced by the first phase of the research. To this aim, the effect of using a higher production temperature to prepare the steel slag mixtures has been analyzed in terms of volumetric properties as well as basic mechanical performance and durability. A reference mixture, prepared with natural virgin aggregate and cement as filler, was also investigated for comparison purposes. Basically, the main experimental findings showed that the mixes prepared with steel slags still suffered poor workability even when higher production temperature was used. This led to a higher strength but more brittle mechanical behavior whereas promising results were obtained in terms of water and aging resistance. Anyway, it is worth noting that the measured performance for the slag mixtures can be mostly considered acceptable according to the requirements usually adopted for material acceptance.