Fatigue Characterization of Bituminous Binders Containing Crumb Rubber from End-of-Life Tires

This paper presents the outcomes of an experimental investigation which focused on the fatigue behavior of bituminous binder for paving applications prepared by combining a single reference neat bitumen with different types of crumb rubber products derived from the processing of end-of-life tires. In the laboratory preparation of the blends, crumb rubber dosage was conveniently limited in order to obtain binders characterized by viscosity values compatible with standard operating conditions normally adopted in the production and compaction of bituminous mixtures. Results obtained from time sweep tests carried out in equi-stiffness conditions showed that fatigue performance is enhanced by the use of the considered crumb rubber modifiers with a dosage-dependent improvement of both fatigue life and crack propagation amplitude. Given that the considered crumb rubber products were quite similar, no significant effects were associated to changes of crumb rubber type.