Fatigue Characterization of Asphalt Rubber Mixtures with Steel Slags

The paper discusses the results of a laboratory testing concerning the fatigue properties of asphalt rubber mixtures (by wet process), made with Electric Arc Furnace (EAF) steel slags (up to 93% of the weight of the aggregates). The experimental trial analyzed different bituminous mixtures, i.e. Stone Mastic Asphalt (SMA), base course and wearing course concretes, by means of the four-point bending test, according to EN 12697-24 Standard Annex D. The purpose was to evaluate the fatigue resistance of the mixtures, considering the dissipated energy approaches, which allow consistent material parameters to be identified, indicative of the damage accumulated in the asphalt mixes. Both aged and unaged samples were tested, in order to investigate the ageing effects. The asphalt rubber mixes presented better fatigue behaviour than the reference mixtures made with conventional or polymer modified bitumen.