This paper describes the results of a research studying the fatigue resistance performances of bituminous concretes for base courses and wearing courses (traditional and SMA type), made with steel slags and bitumen modified with crumb rubber or SBS polymers. The fatigue behaviour was also investigated in conditions of long-term ageing, in order to evaluate the effectiveness of the modification with crumb rubber using the wet process in reducing the fatigue damage in heavily oxidized mixtures. The experimental data, obtained from four point bending tests (4PBT), were interpreted both with the classical methodology based on a 50% reduction of the initial stiffness and with Pronk’s energy approach.
