Abstract
One method for reducing the rutting failure of asphalt pavements is to modify the asphalt binder with polyethylene. However, the instability and phase separation between components has always been a major problem in achieving a homogeneous asphalt binder–polyethylene combination. To improve storage stability, one solution is to use crosslinking agents. In this study, the base asphalt binder was modified by using 3 and 7 % high-density polyethylene (HDPE). Subsequently, 1.5 % polyphosphoric acid (PPA) and 0.5 % sulfur were combined with polymer-modified asphalt binder to improve the stability between asphalt binder and polyethylene as well as reduce phase separation. First, the aging component of the prepared asphalt binder samples was evaluated using the attenuated total reflectance Fourier transform infrared spectrometer analysis. Then, the storage stability of asphalt binder samples was investigated by the frequency sweep test. The rutting resistance of asphalt binder samples was determined using the multiple stress creep recovery test, and finally, the fatigue performance of the rolling thin-film oven–aged asphalt binder samples was evaluated using the linear amplitude sweep test. The results revealed that, unlike the sulfur additive that did not have any beneficial effect on the HDPE-asphalt binder, the PPA increased the resistance of rutting, fatigue cracking, aging, and storage stability for the HDPE-asphalt binder.