Reuse of EAF Slag as Aggregates in Structural Concretes

The growing interest of the international community in a more circular economy has led to the introduction of materials from industrial production and/or recovery in the construction sector, formerly classified as waste for disposal but now considered of fundamental importance for environmental protection and for reducing the exploitation of natural resources. Several studies available in the literature have shown how slags from the production of steel in electric arc furnaces (EAF slags), if properly treated, can be reused for concrete production. Italian steel mills are almost all equipped with electric arc furnaces from which, in addition to the primary material, an estimated 2.1 to 3.1 million tonnes per year of EAF slags can be generated. Unfortunately, about 15–20% of these slags are still destined for landfill disposal. Given the advantages and disadvantages that EAF slags provide to the mix and the possibility of the Italian concrete market to incorporate the entire quantity of slags produced at national level, even with limited replacement percentages, the present work aims to provide a contribution on the study of concrete made with electric arc furnace slags (EAF). Three concrete mixtures have been produced and in two of which the natural fine and coarse aggregates has been replaced by two different percentage of EAF slag, 25 and 50%. Once the mechanical characterisation of the mixtures had been carried out, they were then used to produce full-scale beams in order to study both flexural and shear behaviour.