*2.1. Materials*

In this study, the morphological and mechanical characteristics of alternative aggregates (slags) of variable concentrations were evaluated for their use as concrete aggregates and linked with the performance of the resultant produced high-strength concrete specimens. More specifically, the alternative aggregates were FeNi and Electric Arc Furnace slags. Furthermore, micritic limestone was used as concrete aggregate in order to produce specimens containing only natural aggregates (standard concrete). Moreover, cement of Type II ASTM C 150 (Lafarge) [37] was used as well as potable tap water, free of impurities

such as salt, silt, clay and organic matter, was also used for mixing and curing the concrete. The pH value of water was 7.0. Natural washed sand was also used for the concrete production whose concentration varies from 5.5 to 7.5%. The water/cement ratio was 0.33.
