Effect of Using Rejuvenators on the Chemical, Thermal, and Rheological Properties of Asphalt Binders

Abstract

Rejuvenators are used to restore the properties of reclaimed asphalt pavement (RAP) binders through readjusting the balance between the asphaltene and maltene fractions. To properly understand the effect of rejuvenators, it is important to analyze the chemical changes in the rejuvenated binders and to relate these changes to the rheological properties of the binders. In this study, RAP binders were blended with a bio-based and an aromatic extract petroleum-based rejuvenator additive. Chemical and thermal techniques, such as differential scanning calorimetry (DSC), attenuated total reflection Fourier transform infrared (FTIR) spectroscopy, and saturate, aromatic, resin, and asphaltene determinator (SAR-AD) were used to analyze the control and rejuvenated RAP binders. Glass transition temperatures were obtained using DSC and correlated with rheological measurements using a dynamic shear rheometer (DSR) and a 4 mm plate geometry. From FTIR results, the evolution of the carbonyl and sulfoxide indices with aging were determined and correlated with the complex shear modulus DSR measurements at different aging stages. The SAR-AD analysis was used to determine the changes in the asphalt fractions with the addition of the rejuvenators. Temperature–frequency DSR sweeps and bending beam rheometer testing were conducted, and master curves were constructed for the different binders. From these master curves, the effect of the different rejuvenators on the crossover temperature, glass-transition temperature, and intermediate region temperature range (T IR) was determined.

Future Directions for Applications of Bio-Oils in the Asphalt Industry: A Step to Sequester Carbon in Roadway Infrastructure

“…29 Bio-oils can also be used as rejuvenators. 30 Rejuvenators based on algae, animal waste, or vegetable oil are usually in liquid form, and their introduction to aged asphalt could help revitalize aged asphalt. Bio-oil from oak wood is a bitumen replacer with properties similar to those of bitumen; bio-oil from oak wood can be modified by polymers or rubber, and it is resistant to thermal cracking.…”

Interactions between RAP and virgin asphalt binders in field, plant, and lab mixes

“…Mullapudi et al [20] mixed different proportions of extracted RAP binders with VABs, and it was found that the oxygenated functional groups' indices-ISO and ICO-increased with increasing RAP binders' percentages. The binder in the RAP contained a high asphaltene fraction [21], thus EABs' maltenes and asphaltenes fractions change based on the interactions between the RAP binder and VAB. The TGA is utilized to examine changes in the components of asphalt binders by monitoring changes in thermograph (TG) parameters: the onset temperature (Tonset), endset temperature (Tendset), and residue's percentage.…”

Thermal, Chemical and Rheological Properties of Asphalt Binders Extracted from Field Cores

“…Asphaltene has one peak in the DTG; however, maltene presents two peaks [11]. Thus, the disappearance of the second region in the DTG indicates a decrease in the maltene component of the EABs The RAP binder has a high fraction of asphaltene [19], and thus the fractions of EABs-maltenes and asphaltenes-change based on the interactions between the RAP binder and VAB. These interactions and related changes in asphalt fractions can be explored through TGA.…”