Combined Recycling of RAS and RAP: Experimental and Modeling Approach

The use of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in combination with new materials in asphalt mixes appears to be a good solution to achieve economic and environmental benefits while maintaining or increasing the performances. The main objective of this work is to verify the application of the two blending laws for the prediction of conventional, physicochemical and rheological parameters at the binder scale. After extraction and recovery operations of RAP and RAS binders, the recovered binders were mixed with a virgin bitumen (PG 58-34) in several recycled bitumen ratios (RBR) up to 40% wt. The blends were characterized by conventional (penetration and Ring and Ball softening point), rheological (shear complex modulus) and physicochemical (Infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC)) tests to compare the rheological behavior, the oxidation levels and the glass transition temperature. The 2S2P1D model was used to fit experimental shear complex modulus data. The proposed models describe well the experimental data from conventional, rheological and physicochemical tests.