Rheological properties of asphaltene-modified asphalt binder and mastic

Abstract

Asphaltene is one of the component of asphalt binder. Asphaltene certainly contributes to the elasticity and stiffness of a binder's traditional viscoelastic behaviour. Introducing asphaltene as a separate modifier may improve the qualities of asphalt mastic. The influence of asphaltene on the rheological properties of asphalt binder and mastic is discussed in this paper. Asphalt binder grade 60/70 PEN was modified by adding with 1% asphaltene content. Asphalt mastic was then prepared using asphaltene-modified asphalt binder and aggregates passing 75 μm. A viscosity and a dynamic shear rheometer (DSR) test were performed to evaluate the rheological properties indexes such as rutting factor (G*/sin δ), phase angle δ, complex modulus G* and elasticity modulus of asphaltene-modified asphalt binder and mastic. It is anticipated that adding 1% asphaltene would enhance viscosity, stiffness, and rutting resistance. Based on the data analysis, modified mastic viscosity and stiffness reduced. Increased asphaltene did not improve mastic to be more rut-resistance. Among the three types of asphalt binder, PG76 binder has the best rut-resistance performance, modified asphalt binder takes the second place, and 60/70 PEN has the worst rut-resistance performance. While for the mastics, PG76 mastics have the best rut resistance performance, 60/70 PEN mastics take the second place, and modified mastics have the worst rut-resistance performance. Overall, PG76 mastic had the highest complex shear modulus value (G*), rutting parameter (G*/sin), and phase angle (δ), indicating that it had the best viscosity properties, stiffness, and resistance to rutting. Therefore, it is advised to increase the asphaltene content in order to support future research.