@misc{gulzar_fried_preciado_castorena_underwood_habbouche_boz_2023, title={Towards sustainable roads: A State-of-the-art review on the use of recycling agents in recycled asphalt mixtures}, volume={406}, ISSN={["1879-1786"]}, url={https://doi.org/10.1016/j.jclepro.2023.136994}, DOI={10.1016/j.jclepro.2023.136994}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Gulzar, Saqib and Fried, Andrew and Preciado, Jaime and Castorena, Cassie and Underwood, Shane and Habbouche, Jhony and Boz, Ilker}, year={2023}, month={Jun} }
 @article{fried_xue_gulzar_preciado_underwood_castorena_2022, title={Evaluation of Recycling Agent and Extender Dosage Selection Procedures to Restore the High-Temperature Climatic Performance Grade}, volume={2}, ISSN={["2169-4052"]}, url={https://doi.org/10.1177/03611981221074361}, DOI={10.1177/03611981221074361}, abstractNote={Dosage selection is important for effective use of recycling agents and extenders in asphalt pavements. A standardized protocol for extender and recycling agent dosage selection does not presently exist. NCHRP Project 09-58 established a recycling agent dosage selection procedure that aims to restore the desired high-temperature grade of a blend of recycled binder, virgin binder, and additive. Their simplified procedure relies on the existence of class-specific relationships between the blended system high-temperature grade and additive content. Further, the dosage selection procedure assumes complete recycled binder availability. There is general consensus that complete recycled binder availability is not achieved in practice, which may yield asphalt mixtures with poor rutting performance. This study seeks to evaluate the universality of the slopes proposed in NCHRP Project 09-58 to both extenders and recycling agents and evaluate the rutting resistance of asphalt mixtures prepared using additive dosages selected to restore the high-temperature grade of the blended binder system. This study encompasses one reclaimed asphalt pavement (RAP) and one recycled asphalt shingles (RAS) mixture. Two extender and two recycling agent products were evaluated. The results indicate that different additive types yield different slopes of the blended system high-temperature grade versus additive content. The results also show that uncertainty should be accounted for when establishing a dosage selection procedure to ensure that the blended binder grade does not fall below the desired value. The rutting resistance of mixtures prepared using additive dosages intended to restore the high-temperature grade all passed recommended Hamburg wheel-track criteria.}, journal={TRANSPORTATION RESEARCH RECORD}, author={Fried, Andrew and Xue, Lei Gabriel and Gulzar, Saqib and Preciado, Jaime and Underwood, B. Shane and Castorena, Cassie}, year={2022}, month={Feb} }
 @article{habbouche_boz_underwood_castorena_gulzar_fried_preciado_2021, title={Review From Multiple Perspectives for the State of the Practice on the Use of Recycled Asphalt Materials and Recycling Agents in Asphalt Concrete Surface Mixtures}, volume={2676}, ISSN={["2169-4052"]}, url={https://doi.org/10.1177/03611981211061130}, DOI={10.1177/03611981211061130}, abstractNote={The objective of this paper is to provide information from multiple perspectives on the current state of the practice with regard to using recycled materials and recycling agents (RAs) in asphalt concrete mixtures. This information was collected through a survey of U.S. transportation agencies and RA suppliers combined with a search of RA-related specifications and pilot projects previously constructed. Moreover, a case study describing the Virginia Department of Transportation’s experience with RAs provides a tangible example of how at least one agency is approaching the potential implementation of these technologies. This practice review was achieved by documenting the experience, lessons learned, and best practices of multiple asphalt experienced contractors and asphalt binder suppliers in the Virginia area. This paper follows a similar survey conducted in 2014 as part of NCHRP 09-58 and provides a second look at the use of RAs across North America. Not all state departments of transportation have experience with using RAs. Factors preventing the use of RAs included specification limitations, lack of expertise in processing recycled materials, supporting data, and negative prior experiences. Developing a performance-based testing framework is mandatory for the successful use of RAs. In general, good and frequent communication with the RA supplier is critical and necessary during the planning stages, the production of mixtures, and the continuous quality control by the supplier to resolve issues when they arise. Finally, a strong quality control and quality assurance-testing program should be implemented to ensure that materials meet the properties needed to produce a good-performing mixture.}, number={4}, journal={TRANSPORTATION RESEARCH RECORD}, publisher={SAGE Publications}, author={Habbouche, Jhony and Boz, Ilker and Underwood, Benjamin Shane and Castorena, Cassie and Gulzar, Saqib and Fried, Andrew and Preciado, Jaime}, year={2021}, month={Dec} }