The use of EAF steel slags in hydraulically bound mixtures for road foundations: a laboratory characterisation

The paper discusses the results of a laboratory study, conducted at the Experimental Road Laboratory of the University of Padova, to verify the suitability of a particular type of electric arc furnace (EAF) steel slag to be recycled in the lithic skeleton of cement bound granular material for road pavements. The experimental trial involved a preliminary study of the physical-geotechnical properties of the EAF steel slag by itself, then mechanical characterization of the hydraulic bound mixtures. The formulation of the mixes was done in terms of Proctor, compression and indirect tensile tests. At the end of the study the resilient behaviour of the mixtures was investigated through cyclic triaxial tests. The results have been extremely positive (compression and indirect tensile resistance at 7 days of 3.96 MPa and 0.27 MPa respectively), suggesting that the EAF steel slags can be used as integral substitution of natural aggregates, also with low binder content, so reducing the production costs of the mixtures.