Resistance to Permanent Deformation of Base Courses Asphalt Concretes made with RAP aggregate and Steel Slag

The results are presented of a laboratory investigation aimed at analyzing the rutting susceptibility of asphalt concretes with Reclaimed Asphalt Pavement (RAP) aggregate and Electric Arc Furnace (EAF) steel slag, used at different proportions (up to 70% of the weight of the aggregates), in partial substitution of limestone aggregates. The experimental study has been focused on the characterization of the physical-mechanical properties of the marginal materials, as well as on the mix design and the permanent deformation evaluation (by means of Creep Recovery Tests, Repeated Load Axial Tests, Wheel Tracking Tests) of bituminous mixtures for road asphalt concrete base courses. Since the requisites for acceptance in the Italian Specifications and Standards have been satisfied and given the positive mechanical performance (indirect tensile strength at 25°C on dry samples up to 2.35 MPa, depending on the mixture), it has been verified that the marginal aggregates investigated can be used as substitution of the lithic materials in the base courses, also with very high content (up to 70% on the weight of the aggregates)