Effect of SARA on Rheological Properties of Asphalt Binders

Abstract

As the basic chemical components of asphalt binders, the fractions of saturates, aromatics, resins, and asphaltenes (SARA) have crucial effects on the rheological properties of such binders. Thus, two kinds of neat asphalt binders and derived binders with different SARA proportions were studied in this paper. The dynamic rheological properties of two kinds of neat asphalt and the derived binders were tested by frequency sweep tests. Their static rheological properties were tested by creep and stress relaxation tests. The effect of SARA on dynamic modulus, phase angle, creep compliance, and relaxation modulus were analyzed. The results showed that the dynamic modulus increases with increases in asphaltenes or resins content and decreases with increases in saturates or aromatics content. Saturates have the greatest effect on dynamic rheology properties. Shape index R shows a decreasing trend with increases in asphaltenes or resins content and an increasing trend with increases in saturates or aromatics content. Creep compliance and residual relaxation modulus decrease with increases in asphaltenes or resins content and increase with increases in saturates or aromatics content. SARA fractions have important effects on the rheological properties of asphalt binders.