Airfield and Highway Pavements 2019 274 © ASCE Impact of Asphalt Modifier Dosage on Modified Binder Rheology and Chemistry with Long-Term Aging Punit Singhvi 1 ; Ahmet Karakas 2 ; Hasan Ozer 3 ; Imad L. Al-Qadi 4 ; and Kamal Hossain 5 1 Graduate Research Assistant, Illinois Center for Transportation, Univ. of Illinois at Urbana- Champaign, 1611 Titan Dr., Rantoul, IL 61866. E-mail: singhvi3@illinois.edu 2 Visiting Scholar, Illinois Center for Transportation, Univ. of Illinois at Urbana-Champaign, 1611 Titan Dr., Rantoul, IL 61866. E-mail: skarakas@istanbul.edu.tr 3 Research Assistant Professor, Illinois Center for Transportation, Univ. of Illinois at Urbana- Champaign, 1611 Titan Dr., Rantoul, IL 61866. E-mail: hozer2@illinois.edu 4 Bliss Professor of Engineering, Illinois Center for Transportation, Univ. of Illinois at Urbana- Champaign, 1611 Titan Dr., Rantoul, IL 61866. E-mail: alqadi@illinois.edu 5 Visiting Scholar, Illinois Center for Transportation, Univ. of Illinois at Urbana-Champaign, 1611 Titan Dr., Rantoul, IL 61866. E-mail: kamalh@mun.ca ABSTRACT Asphalt modifiers/additives are increasingly used in pavement industry. Additives are commonly used as softeners to decrease the binder performance grade (PG), while polymer modifiers are usually used for heavy traffic applications to reduce permanent deformations. Recently, rejuvenators have been used in recycled pavement applications to reduce cracking susceptibility and as retarders to moisture damage. These modifiers can be derived from crude petroleum and sometimes from a bio-based feedstock. The origin of crude binder and modifier source affects the resulting binder-modifier chemical interaction. The inherent chemical variability affects the rheological performance of modified binders. It also impacts the aging potential of these binders and thereby affecting its long-term field performance. In this study, binders modified with softeners/rejuvenators at various dosages were evaluated for their performance under long-term aging. Rheological characterization of modified binders was determined using frequency sweep, linear amplitude sweep, and low temperature performance with parameters such as Glover-Rowe, R-value, crossover frequency, ∆Tc, while the chemical characteristics were determined using Fourier transform infrared spectroscopy (FTIR), and thin layer chromatography and flame ionization detection (TLC-FID). An optimum dosage of the rejuvenator studied was recommended to maximize performance of the modified binder. Keywords: Asphalt rheology, chemical characterization, long-term aging, asphalt modification. INTRODUCTION Asphalt modifiers/additives are increasingly used in pavement industry. Additives are commonly used as softeners to decrease binder performance grade (PG); while polymer modifiers are used for heavy traffic applications to reduce permanent deformations. Recently, rejuvenators have been used in recycled pavement applications to reduce cracking susceptibility and as retarders to moisture damage. These modifiers were commonly derived from crude petroleum and sometimes from bio-based products. The source of crude binders and modifiers affects the resulting binder-modifier chemical interaction. The inherent chemical variability affects the rheological performance of the modified binders. It also impacts the aging potential of these binders and thereby affecting pavement long-term performance. Airfield and Highway Pavements 2019 Downloaded from ascelibrary.org by University of Illinois At Urbana on 10/13/19. Copyright ASCE. For personal use only; all rights reserved.