Comparison Between Rheological Behavior of a Neat Asphalt Binder and a Bio-Binder from Renewable Source

Binders produced from biomass are turning on an attractive alternative to construct sustainable roadways, replacing partially, or even totally, the asphalt binder content—petroleum-based—of the asphalt mixtures. This paper presents a comparison between a neat asphalt binder and a wood-based bio-binder in terms of their rheological behavior at different aging stages. For both binders, the dynamic shear modulus, │G*│ and the phase angle, δ, at different frequencies and temperatures was determined using the Dynamic Shear Rheometer (DSR). The permanent deformation susceptibility and the fatigue behavior were also investigated through the Multiple Stress Creep and Recovery (MSCR) test and the Linear Amplitude Sweep (LAS) test, respectively. Results showed that the bio-binder used in this study has higher dynamic shear modulus than the asphalt binder studied, which is also observed in the MSCR results, where the bio-binder presented a better resistance to permanent deformation when compared to the asphalt binder. Regarding to fatigue, LAS results suggest that the neat asphalt binder has a better response when compared with the bio-binder. Besides, a Performance Grade classification was carried out for both binders, however, it was not possible to determine the lowest temperature for the bio-binder, as the results observed for this material did not meet the established limits by the method. One reason for that could be that these limits, and the method itself, were specified for asphalt binder and might not be suitable for other types of binders (not petroleum based). As a conclusion, the wood-based bio-binder displayed characteristics that could be used in the construction of roadways, but it is necessary to develop characterization methods that allow its proper classification.