Rheological characterization of reversibility between aging and rejuvenation of common modified asphalt binders

Abstract

In order to study the reversibility between aging and rejuvenation of modified asphalt binder, a kind of virgin asphalt was selected, and then three kinds of modified asphalt were prepared based on this virgin asphalt. The short-term and long-term aging tests were carried out for the four asphalts. Then three kinds of rejuvenation tests were carried out for the aged asphalt, including commercial rejuvenator, aromatic oil and warm mix rejuvenator. Dynamic shear rheometer (DSR) was used to carry out frequency scanning tests at different temperatures. According to the principle of time temperature equivalence, the master curves of different modified asphalts were constructed, and the rheological properties of asphalt during aging and rejuvenation were studied. By comparing the parameters including complex modulus and hardening index, the rejuvenation effects of viscoelastic properties of modified asphalt were evaluated. Based on the complex modulus of virgin asphalt and modified asphalt, the aging rejuvenation reversible index RM of modified asphalt is proposed to evaluate the recovery of rheological properties of asphalt by different rejuvenators. The results show that the modulus of three kinds of modified asphalt will increase with the deepening of aging. Warm mix rejuvenator can reduce the complex modulus of virgin asphalt, SBS modified asphalt and rubber powder modified asphalt most significantly, followed by the rejuvenator, and the aromatics oil reduced least obviously. This applied to both short-term aging and long-term aging. This research provides a better understanding on the effectiveness and limitation of current rejuvenation techniques and rejuvenators on common asphalts, which is good for the further improvement on production and techniques.