Rheological and Mechanical Properties of Bitumen Modified with Sasobit, Polyethylene, Paraffin, and Their Mixture

Abstract

Additives such as Sasobit, polyethylene, and paraffin can enhance the durability of pavement and prevent further environmental pollution by changing the functional behavior of bitumen. Combining Sasobit with two other low-priced waxes and achieving a satisfactory performance can help moderate the price of Sasobit, making its use pervasive. Therefore, this study aimed to investigate the mechanical and rheological properties of bitumen modified with Sasobit, polyethylene, and paraffin additives, separately and simultaneously. Accordingly, penetration, softening point, ductility, rotational viscometer, dynamic shear rheometer, and bending beam rheometer tests were performed on 10 mixtures in both aged and unaged states. The results of rheology tests indicated an improvement in the phase angle and high-temperature performance of bitumen modified with Sasobit and polyethylene waxes. The results of the rotational viscometer test indicated that the viscosity of bitumen modified with the Sasobit, polyethylene, and paraffin waxes and their mixture was reduced at high temperatures. Sasobit, polyethylene, and paraffin and their mixtures worsened the medium- and low-temperature performances; however, these negative impacts were lower in the combination of Sasobit and polyethylene. © 2019 American Society of Civil Engineers.