Use of electric arc furnace slag for the manufacture of concrete paving blocks

Two fine (0-2 mm) and (0-4 mm) fractions of electric arc furnace steel slag (EAF slag), generally unsuitable for applications in road constructions as aggregates for bituminous mixtures, were respectively used in cement mortars and concrete paving blocks, as a partial or total replacement for natural sand. When submitted to the compressive strength test prescribed by the EN 197-1 Standard, the cement mortars containing 100% EAF slag and cured for various lengths of time gave the best results (10-20% strength increase) due to the higher intrinsic strength of artificial aggregate, compared to that of natural sand. With reference to the second application, the results of abrasion, unpolished slip resistance, indirect tensile and compressive strength test were generally very satisfactory. Regarding the mechanical strength, the optimum EAF slag concentrations were 60-80%, probably owing to an inadequate bonding of paste matrix to aggregate particles for the cementitious mixture made with 100% EAF slag.