Performance Evaluation and Characterization of Extracted Recycled Asphalt Binder With Rejuvenators

Abstract

Rejuvenators are used in the asphalt industry to improve the performance and durability of aged binders and facilitate the use of recycled asphalt materials. The purpose of this study was to evaluate the impact of rejuvenator type and dose on the laboratory performance of asphalt binders. For this study, recycled asphalt pavement (RAP) and extracted RAP binder were obtained from an airfield reconstruction project located in Atlantic City, NJ. One petroleum-based (aromatic extract) and three organic-based (corn oil, tall oil, and modified vegetable oil) rejuvenators were evaluated in this study. Each rejuvenator was used at two different rejuvenator doses (6% and 12% by total RAP binder weight) and was aged at three different levels. Performance grade testing, frequency sweep tests, critical temperature differential (ΔTc ), and Fourier transform infrared spectroscopy (FTIR) tests were conducted. Results showed that the use of rejuvenators lowered the high and low performance grade of extracted RAP binders, in particular organic-based rejuvenators had a greater impact on the performance grade. ΔT c was also improved through the use of rejuvenators. In fact, the extracted RAP binder exceeded the high severity ΔTc threshold (−5°C), whereas the rejuvenated RAP binders improved ΔT c to values greater than the low severity threshold (−2.5°C). Similar findings were observed from the Glover-Rowe parameter as well, in which rejuvenated RAP binders improved the cracking resistance of the extracted RAP binder. When assessing the aging susceptibility, modified vegetable oil and corn oil rejuvenators showed the smallest change in performance between aging levels.

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

“…It was found that the use of waste maize oil resulted in a higher reduction in the viscosity of the bitumen, while fresh maize oil had lower stability at different temperatures. Samara, Offenbacker, Mehta, Ali, Elshaer, and Decarlo studied the effect of organic and petroleum products on the performance of bitumen modified by these oils. They reported that corn- and vegetable-oil-modified bitumen were less susceptible to aging compared to tall oil, and aromatic extract oil.…”

Understanding the State Agency Policies toward RAP Usage in the United States: State of Practice

“…Such high stiffness of binders due to aging results in mixtures highly prone to cracking [6,7]. To reduce the influence of aged binders and improve the interaction between RAP material and virgin material, researchers suggest rejuvenation, which softens aged binders and improves their cracking resistance [8]. In addition, to address the variation in gradation and non-homogeneity in RAP materials, studies mention fractionation for controlled mixture designs [9].…”