Modelling of rheological and chemical properties of asphalt binder considering SARA fraction

Modelling the rheological properties and chemical characteristics of asphalt material has been a hotspot. In this study, 20/40 and 60/80 pen grade asphalt binders named binder A and binder B were used to blend eleven binder samples. After that, a novel column chromatography was applied to collect sufficient SARA (Saturates, Aromatics, Resins and Asphaltenes). The Dynamic Shear Rheometer (DSR) test was used to develop the viscoelastic master curves for binders and their subsets. The Fourier Transform Infrared Spectroscopy (FTIR) test was conducted to identify and semi-quantitatively analyze the notable functional groups. Linear combination models were conducted between rheological model parameters and chemical components. It was found that the contents of Asphaltenes and Saturates increased, while those of Resins and Aromatics decreaed with the addition of binder A, resulting in the increased colloidal instability index (CII) values. In addition, the Saturates had constant value of phase angle, while the phase angle master curves of Aromatics and Resins showed plateau values of 80 degrees. Resins containing more aromatic structures had a lower frequency (high temperature) value at this plateau value. Furthermore, the main findings were that I-c=c and I= (C-H) of Aromatics as well as I=(C) - (H) and I-S=(O) of Resins had significant relationships with binder A content. Statistically, several parameters such as C-Resins, C-Asphaltenes, CII, I-C=(C) of Aromatics, I= (C)-(H) of Aromatics, I= (C)- (H) of Resins, and I-S=(O) of Resins had significant effects to develop multiple linear regression model on asphalt rheological properties.