Estimation of Complex Shear Modulus of Binder Blends Produced with RAP Binder and Rejuvenator

The linear viscoelastic behavior of various blends of a fresh binder (a straight-run 50/70 penetration grade binder) and a RAP-extracted binder, with and without rejuvenator (a mixture of vegetal oils), was studied. The experimental plan includes a total of 9 binders: fresh binder, RAP binder, 3 blends of RAP binder and rejuvenator and 4 blends of fresh and RAP binders with and without rejuvenator. The rejuvenator content used for blends was 0%, 5%, 10% and 15% by mass of RAP binder within the blends. Complex shear modulus of all blends was obtained by means of Dynamic Shear Rheometer (DSR) tests at temperatures ranging from 25 to 85 °C and for frequencies ranging from 0.1 to 10 Hz. Two different approaches were proposed in order to estimate the norm of complex shear modulus of different binder blends from experimental results obtained for the base constituents. Good correlations with experimental data were observed.