## 1 Introduction  
The production of crude steel in Europe in the year 2017 was 168.3 Mt, almost 4% higher than in 2016, while the production by electric arc furnaces stands at 40.3% of total production (67.8 Mt) [1]. This steel production determines the amount of electric arc furnace slag (EAFS) generated during the fusion processes of scrap, totalling 18 Mt for the year 2016 according to the Euroslag. In Europe, 12 Mt of cast iron was generated in 2017. These values of production reveal the volume of slag resulting from the steel and cast iron industries that ends in landfills. Several authors have incorporated different types of industrial waste as SCM's to concrete to modify its properties [2; 3; 4]. The pozzolanic properties of the slag generated in steel processes depend on the cooling process. With rapid cooling (as is the case of cupola slag) using water, the vitrification of the slag occurs, leaving the silica in an amorphous form and, therefore, susceptible to reaction. On the contrary, slow cooling (case of EAFS) promotes the complete crystallization of the phases and the inertization of the final product, thus not compromising its dimensional stability. The pozzolanicity of EAFS has been studied, but its reactivity has been reported to be rather weak [5] although it can be improved by remelting treatments [6]. The content of periclase (MgO) in the slag causes a risk of potential expansion because the process of transformation into brucite [Mg(OH)\({}_{2}\)] by hydration is slow or even delayed, putting the dimensional stability at risk. Given the possible expansive reactions, it is important to verify the efficiency of the stabilization treatments [5]. Another problem present in these aggregates is the significant deficit of particle sizes that pass through the smaller sieves in the sands. Therefore, the manufacture of mortars and concretes with EAFS sand entails mixing by combining them, either with natural sand or with inert filler [7; 8]. Another interesting practice in recovery/recycling strategies (in addition to incorporating EAFS aggregates) is to incorporate recycled aggregates from Construction and Demolition Wastes (C&DW) to self-compacting concrete [2; 9; 10]. It has been demonstrated that their mechanical properties and durability [2; 11; 12; 13] are suitable for structural concrete and they can be recycled several times [14]. SCMs are important for the self-compacting concrete (SCC), since they reduce the intergranular interaction [14], increase the cohesion and the flowability of the mixture, improve the hydration of the paste [15; 16], and strengthen the resistance to segregation. In hardened concrete, SCMs typically reduce capillarity and permeability but also mechanical properties can be reduced [14; 17]. The cements most used for the manufacture of high strength SCC are Portland type I, however, blends containing one or more SCMs [18] and 350 kg/m\({}^{3}\) of CEM can be used readily [19]. It is recommended not to exceed 500 kg/m\({}^{3}\) (to avoid shrinkage problems) and to use SCMs to improve the workability of the fresh concrete. Several authors [20; 21] have established that drying shrinkage increases with drying speed and is proportional to the volume of cement paste, while the opposite occurs by increasing the lime filler content. The use of cupola slag as a concrete SCM is not a common application despite of its sustainable benefits. Nevertheless, the use of granulated cupola furnace slag (GCFS) as fine and coarse aggregate (0-16 mm) in concrete does not seem a viable option [22]. However, some authors have demonstrated by the manufacture of mortars with various replacements [23] that is suitable to be used as SCM with the right activation process. Nevertheless, great reactivity has been reported when acting as substitution of ordinary Portland cement (OPC), showing 30% compressive strength gains for 15% replacements at 28 days [22]. The use of SCMs increases the concrete strength, and in greater proportion, by using SCMs with pozzolanic properties.