Low temperature performance characteristics of polyethylene modified asphalts - A review

Low-temperature property of polyethylene (PE) modified asphalt has long been a controversial issue. In order to better understand the low-temperature anti-cracking properties of PE modified asphalt binder, the low-temperature cracking mechanism of PE modified asphalt binder and existing low-temperature property evaluation methods were reviewed firstly. Meanwhile, the factors that affect the low temperature performance of PE modified asphalt were comprehensively analyzed. On the other hand, the state of art of low-temperature performance and evaluation methods of PE modified asphalt mixture were discussed as well as the factors that affect the low temperature performance of PE modified asphalt mixture. It was found that the PE particles or fiber acted as "bridge" that can block the propagation of cracks, leading to the improvement of low-temperature properties of asphalt binder. Low-temperature properties of PE modified asphalt binder are highly dependent on the properties of base asphalt binder and PE essentially and PE content as well which dominated the interaction between PE and base asphalt binder. Additionally, the PE modified asphalt mixture exhibited better low-temperature properties than base asphalt mixture based on the existing low-temperature properties evaluation methods. However, the low temperature properties of PE modified asphalt binder is worse than those of base asphalt binder. The reason behind this phenomenon is believed to be that the existing evaluation methods of low temperature anti-cracking performance of PE modified asphalt binder is improper. Therefore, it is necessary to explore some more appropriately complete methods to evaluate the low-temperature properties of PE modified asphalt binder for the PE modified asphalt community. (C) 2020 Elsevier Ltd. All rights reserved.