Study of the permanent deformation of binders and asphalt mixtures using rheological models of fractional viscoelasticity

ABSTRACT: The accumulation of load on asphalt pavement as a result of increased vehicle traffic generates problems in the asphalt layer due to permanent deformation. For correct design, it is essential to carry out a rheological characterization of the aggregate-binder materials that make up the asphalt mix. This article shows the analysis of permanent deformation based on the rheological behavior of asphalt mixtures and binders. Experimental tests based on creep and recovery phenomena allow the study of permanent deformations using theoretical models of fractional viscoelasticity. The rheological characterization allows us to detail the elasticity of the aggregate, ξ2, and the elastic-viscous properties of the different binders used, ξ1 and η .The results obtained show that it is possible to predict the deformations of the recovery phenomenon in asphalt mixtures from the rheological values (aggregate-binder) obtained in the creep process. Besides, the properties of the asphalt binder (ξ1 and η) correlate with the recovery phenomenon of the MSCR test for conventional and modified materials. The methodology proposed allows a better understanding of the states of permanent deformation to improve the design of binders and asphalt mixtures..The authors gratefully acknowledge the institutional support provided by the Department of R+D of the University Austral of Chile (DID UACh) and to the Santander Bank Iberoamerican Scholarship Program, which made it possible to carry out this research. The authors would also like to thank the GITECO and GCS research groups from the University of Cantabria (Spain) for their support