A Study on Xinjiang Asphaltite as an Asphalt Modifier. Part II: Rheological Evaluation of Modified Asphalt Binders

Abstract

Modified asphalt binders with varying Xinjiang asphaltite contents between 4% and 16% were prepared in laboratory. Dynamic shear rheometer temperature sweep and time sweep tests, bending beam rheometer tests, some conventional tests including penetration and softening point were performed to analyze the rheological properties of these asphalt binders and evaluate Xinjiang asphaltite potential as asphalt modifier. Test results showed with the Xinjiang asphaltite content increasing, complex shear modulus increased and phase angle decreased, which indicated Xinjiang asphaltite could improve the elasticity and deformation resisting of binders. Fatigue failure life of asphalt binders grew exponentially with Xinjiang asphaltite content. Moreover, Xinjiang asphaltite had an adverse effect on the low temperature performances of asphalt binders based on measured creep stiffness and m-value. Based on these test results modification mechanism of Xinjiang asphaltite was analyzed. It is thus suggested that Xinjiang asphaltite is better suitable as a high temperature resistant and anti-fatigue asphalt modifier material.

Keywords:

• fatigue
• high temperature performances
• low temperature performances
• modified asphalt binders
• rheological properties
• Xinjiang asphaltite