Rheological properties of amorphous poly alpha olefin (APAO) modified asphalt binders

The rheological properties of amorphous poly alpha olefin (APAO) modified asphalt binders were investigated through rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR) tests in the laboratory. Two types of APAOs and four percentages of APAO were selected in the study. RV results indicate that the addition of APAO increases the viscosity of modified asphalt binder at high temperatures. DSR measurements show that the elastic property of asphalt binder is enhanced and the failure temperature is improved due to the addition of APAO. In addition, BBR results demonstrate that additional APAO has negative effects on the creep stiffness and creep rate of the modified asphalt binders. The temperature susceptibility of asphalt binder is reduced at high, intermediate, and low temperature zones after adding APAO. Moreover, this study found that APAO K3050 has better modification than K3020 due to its higher viscosity.