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Title: Mixture Validation of Recycling Agents Dosage Selection Method in Asphalt Mixtures with High Recycled Materials Contents
Accession Number: 01661024
Record Type: Component
Abstract: State Departments of Transportation (DOTs) and contractors recognize the environmental and economic benefit of utilizing reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt mixtures. However, recycled asphalt mixtures with high recycled materials contents can be excessively stiff, brittle, and prone to cracking. The use of recycling agents, or rejuvenators, can significantly reduce mixture stiffness and improve performance, depending on a number of factors including the type, source, and amount of RAP/RAS, and the type and dosage of the recycling agent. This study investigated the performance of recycled asphalt mixtures with high RAP and RAS contents with various recycling agent dosages, after short- and long-term aging. The recycling agent dosages were calculated to (1) restore the recycled binder blend (base [virgin] binder and recycled binders) to the low-temperature performance grade (PGL) or (2) reach the continuous high-temperature performance grade (PGH) of the target binders specified based on climate and traffic requirements per DOT specifications. Resilient modulus (MR), dynamic modulus |E*|, Illinois flexibility index (I-FIT), and Bending Beam Rheometer for mixtures (BBR m) tests were performed to characterize stiffness and intermediate-temperature and low-temperature cracking resistance. Rutting resistance was verified using the Asphalt Pavement Analyzer (APA). Results showed that adding recycling agent at dosages to restore PGL reduced the stiffness and improved the cracking resistance, but most of the improvement diminished with long-term aging. Adding recycling agent at dosages to reach PGH resulted in significantly reduced mixture stiffness and improved cracking resistance regardless of aging level.
Supplemental Notes: This paper was sponsored by TRB committee AFK30 Standing Committee on Non-Binder Components of Asphalt Mixtures.
Report/Paper Numbers: 18-01532
Language: English
Authors: Pagination: 6p
Publication Date: 2018
Conference:
Transportation Research Board 97th Annual Meeting
Location:
Washington DC, United States Media Type: Digital/other
Features: References; Tables
TRT Terms: Uncontrolled Terms: Subject Areas: Highways; Materials; Pavements
Source Data: Transportation Research Board Annual Meeting 2018 Paper #18-01532
Files: TRIS, TRB, ATRI
Created Date: Jan 8 2018 10:23AM
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0000-0002-9443-4429