Rheological characteristics of alternative modified binders Lingqing Liu a , Feipeng Xiao b,⇑ , Henglong Zhang c , Serji Amirkhanian d a School of Highway, Chang’an University, Xi’an, China b Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, China c School of Civil Engineering, Hunan University, Changsha, China d Department of Civil, Construction, and Environmental Engineering, University of Alabama, Tuscaloosa, USA highlights  Two base binders and fourteen modified binders produced with seven alternative additives were studied.  Rheological characteristics of binders at high and low temperature at three aging states were discussed.  Both binder source and additive type have influence on the rheological properties.  Recovery percentage has a good correlation with the phase angle of the alternative binders at RTFO state. article info Article history: Received 30 December 2016 Received in revised form 17 March 2017 Accepted 26 March 2017 Keywords: Polymer Alternative Rheology MSCR Aging state abstract The rheological characteristics of two base binders and fourteen modified binders produced with seven additives at three aging states were studied. The test results included viscosity, failure temperature, rut- ting resistance factor, phase angle, complex modulus, percentage recovery value, fatigue factor, stiffness and m-value. It can be concluded that a proper concentration of alternative additive could be used to effectively achieve PG 76-22 binders. In addition, the binders modified with two of three new polymers showed weak resistances to low temperatures. Furthermore, the recovery percentages of alternative bin- ders were relatively correlated to their phase angles at the short aging states. Meanwhile, this study also indicated that both binder source and alternative type determined the rheological characteristics of their modified binders. Ó 2017 Elsevier Ltd. All rights reserved. 1. Introduction It is well known that polymerized asphalt binders have higher viscosity, softening point, and failure temperature as well as greater elastic recovery, bonding strength and ductility [1–4]. These polymers generally include traditional styrene–butadiene– styrene (SBS), styrene–butadiene-rubber (SBR), and crumb rubber, as well as Elvaloy Ò , ethylene vinyl acetate (EVA), polyethylene, and others [2,5–7]. It is generally considered that a blended polymer and virgin asphalt result in the absorption of the light molecular weight oil fraction and the swelling of the polymer [4,6,8,9]. These swollen strands of the polymer connect together in the asphalt and form a three-dimensional network, which effectively improves the per- formance characteristics of the modified asphalt binders [8]. How- ever, these polymers generally have various molecular structures and the formed three-dimensional network varies from one poly- mer to another. Therefore, the internal cohesive and adhesive behaviors of these polymerized asphalt binders are dependent on the base binder source and polymer type [5,9]. SBS behaves like an elastic rubber at ambient temperatures and like a plastic when heated. However, crumb rubber from scrap tire is generally difficult to process due to cross-linked properties. The asphalt binders modified with elastomeric modifiers such as crumb rubber, SBS, and SBS-rubber yielded higher recoveries than those made with plastomeric modifiers, such as Elvaloy and EVA [10]. Some research articles indicated that approximately 75% of all polymer modified asphalts utilized elastomeric modifiers as the additives to improve the performance properties, while only 15% of them used plastomeric. The remaining 10% of modified asphalts used other materials, such as sulphur and acid [11–14]. In general, plastomers exhibit high early strength but are less flexible and more prone to fracture under high strains than elastomers [15]. http://dx.doi.org/10.1016/j.conbuildmat.2017.03.193 0950-0618/Ó 2017 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: fpxiao@tongji.edu.cn (F. Xiao). Construction and Building Materials 144 (2017) 442–450 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat