Evaluation of the performance and temperature susceptibility of gilsonite- and SBS-modified asphalt binders

This study investigated the effect of gilsonite and Styrene-Butadiene-Styrene (SBS) as asphalt binder modifiers on the physical and rheological properties of asphalt binders. For this, binder tests such as penetration test, softening point, rotational viscosity (RV), Dynamic Shear Rheometer (DSR), and Bending Beam Rheometer (BBR) were conducted on the neat and modified binders. The effect of gilsonite and SBS on the binder temperature susceptibility was also investigated by measuring Penetration Index (PI), Activation Energy (AE) and Viscosity-Temperature Susceptibility (VTS) of all the study binders. Fourier-Transform Infrared Spectroscopy (FTIR) test was directed toward investigation of the compositions' structure. The statistical analysis was also utilized to investigate the effect of gilsonite and SBS on the physical and rheological properties and temperature susceptibility of asphalt binders. The results indicated that incorporation of gilsonite and SBS to asphalt binder decreases the temperature susceptibility and improves mechanical and rheological properties of the asphalt binders. In addition, the results showed significant relationships between PI, AE and VTS with high temperature performance grade (HT) for almost all the modified binders. Results of Analysis of Variance (ANOVA) revealed that even though the binder modifier type has no significant effects on PI, AE, VTS, and viscosity, the modifier dosage can significantly affect these parameters.