Effects of Waste Polyethylene on the Rheological Properties of Asphalt Binder

Recycling of waste plastic is an issue of great concern worldwide because of its considerable quantity and growth. The effects of waste polyethylene (PE) on the rheological properties of asphalt binder were investigated in this research. Three types of PE were adopted to prepare modified binders with contents ranging from 2 to 6 %. A viscosity test, performance grade test, frequency sweep test, amplitude sweep test, and linear amplitude sweep test are conducted to study rheological properties of PE modified binders, compared with base binder and binders modified with styrene-butadiene-styrene and crumb rubber modifier. The test results indicated that the high temperature properties of asphalt binders could be effectively improved by the PE modifiers with different types and contents. The high temperature grade and rutting resistance factor of PE modified binder can be increased significantly when compared with the base binder. With the increased PE content, the complex modulus increased, whereas the phase angle values decreased in most test frequencies and shear strain, which implied that the usage of PE not only reinforced the viscosity of binders but also enhanced the elasticity. The fatigue properties of PE modified binders were improved, especially at the lower shear strain range. However, PE modifier had a negative effect for asphalt binder on low temperature property.