Steel slag aggregate in concrete

This chapter introduces the use of steel slags in concrete, distinguishing the main types of steelmaking byproducts that can find a valorization as an aggregate in cement-based materials. Among the different metallurgical slags, it is worth citing blast furnace slag, basic oxygen furnace slag, electric arc furnace slag (EAFS) and lastly, secondary metallurgy slags, for example ladle furnace slags. For those materials, a review of current statistics about their production and market availability, their main properties and recycling potential in concrete is provided. A special focus will be put on EAFC, which is concrete with EAFS: its characteristics will be explained in detail, compared to those of natural aggregate concrete (NAC). A detailed bibliographic review of the most relevant advances within this field adds weight to the analysis that is reported. As a main outcome, on the one hand, the main limitations for their safe use in large-scale projects are highlighted; on the other hand, examples of real applications are presented.