Effect of Polyethylene Grafted with Maleic Anhydride on Asphalt Properties

Low-density polyethylene (PE) was grafted with maleic anhydride (MAH) in solution, which was proved by the infrared (IR) spectrum test result. The grafting ratio peaked at 3.3% as the grafting temperature maintained at 90°C. Compared with the PE-modified asphalt, approximately a 5°C increase of the softening point of the PE-MAH–modified asphalt was observed. Once the dosage of the PE-MAH was higher than 3%, the penetration index of the PE-MAH–modified asphalt was considerably enhanced, whereas its equivalent breaking point was declined radically. In addition, the elastic recovery test supports that the PE-MAH–modified asphalt exhibits a superior capacity of recovering deformation than PE-modified asphalt. The performance grade (PG) test results show that PE-MAH–modified asphalt is preferable to PE-modified asphalt both at high temperature and low temperature. The rutting test results of AC-13 verify that PE grafted with MAH contributes to the higher temperature stability and the lower displacement.