Rheological and chemical characterization of deoiled asphalt modified with FCC slurry

The application of asphalt with low penetration in warm areas to improve rutting-resistance has attracted great interest in recent years. Deoiled asphalt (DOA) and slurry, by-products of solvent deasphalting and fluid catalytic cracking respectively, are utilized with low value-added. The objective of this work was to prepare paving grade asphalt by blending various proportion of FCC slurry with DOA. The effect of chemical composition on viscoelastic characteristics of the blend was investigated and special emphasis was placed on the linear viscoelasticity and viscous flow behavior as well as on empirical tests. The results revealed that SARA fractions of the blends are close to asphalt and are compromise between DOA in which the content of asphaltenes is high and slurry in which is rich in aromatics. Also, SARA fractions have a significant influence on the rheological properties of the blends. Asphaltenes have been proved to enhance the moduli of asphalt and low penetration blends have demonstrated high rutting and deformation resistance especially at high temperatures. Taking into account the balance between workability and in-service performance, application of the 40 wt% slurry in DOA is highly recommended. It is indicated that a more inferior aging resistance with the increase of slurry in DOA. As a result, it is a highly effective and meaningful way to utilize DOA and FCC slurry.