Use of Marginal Materials in Road Constructions: Electric-Arc Furnace Slag

Electric-arc furnaces are one of the most common ways followed by steelworks for the steel production. In Italy, they generate some two million tons of waste materials per year; from an international point of view, only a minor part of these wastes is reused as marginal materials. In road construction the recycling of electric-arc furnace slag is very interesting because of the significant environmental considerations connected with this matter. The Authors propose the use of EAF slag for the stabilization of soils, giving at the same time a complete survey of the percentages of use and of the deriving benefits. Therefore, chosen a study soil, three different binary mixes soil-EAF slag are analyzed with slag percentages equal to 10%, 15% and 20%, and finally the 20% percentage is considered the best. Subsequently, the study considers two additional ternary mixtures, soil-EAF slag-hydrated lime, with optimal percentage of slag equal to 20% and hydrated lime equal to 2% and 4%. The analysis of the five admixtures prepared, from the point of view of compaction tests, CBR tests in optimal conditions and after water imbibitions and compression test with free lateral expansion, allowed an investigation on the performances of each of them and the conclusion on useful design indications for the use of such slag in road constructions.