Short-term aging resistance investigations of polymers and polyphosphoric acid modified asphalt binders under RTFOT aging process

High viscosity is an important feature of SBS modified asphalt, but it is not always favorable because it need more energy to achieve the same viscosity for mixing and construction. Therefore, there are many attempts to improve rheological properties, and on the other hand maintain excellent high-temperature and low-temperature properties of SBS asphalt. Some researchers found that the polyphosphoric acid (PPA) can change the road performance and rheological properties (such as viscosity) of the modified asphalt effectively. The objective of this study is to investigate the high-temperature rheological properties and short-term aging resistance of SBS and three alternative polymer modified binders with/without PPA under Rolling Thin-Film Oven (RTFO) aging process. The rheological properties of these modified binders were tested by DSR and BBR under RTFO short-term aging. The test results indicated that some physical properties such as failure temperature, complex modulus were changed while SBS was replaced partially by PPA, and some properties such as zero shear viscosity, relaxation stress were not influenced regardless of RTFO short-term aging. Therefore it shows that PPA could improve the short-term aging resistance of modified binders. (C) 2018 Elsevier Ltd. All rights reserved.