Micromechanical contribution for the prediction of the viscoelastic properties of high rate recycled asphalt and influence of the level blending

This research deals with an experimental and micromechanical study of high rate recycled asphalt with 70% of RAP. Rheological measurements of shear complex modulus of virgin, RAP and blended binders were performed at different temperatures and frequencies. Then, a micromechanical model based on the generalized self-consistent scheme (GSCS) was suggested for the prediction of the effective mechanical properties of the recycled asphalt. The GSCS-based approach aims to homogenize the heterogeneous material taking into account the intergranular porosity, on the one hand, and the possible interactions between its phases on the other one. The suggested method was compared to a step-by-step (successive) homogenization approach and literature data in elastic case were used for this purpose. The results have shown that the GSCS-based approach presents a good agreement with the data especially for higher volume fractions of aggregates. Furthermore, the significant influence of the blend homogeneity level on the estimation of the effective mechanical properties of the recycled asphalt was highlighted.