Physical and chemical properties of recycled bitumen incorporating rejuvenator

Abstract

The usage of reclaimed asphalt pavement (RAP) in recycled asphalt mixture caused the bitumen to become stiffer. Additional of rejuvenator or rejuvenating agent is required to reduce the stiffness and change the properties of bitumen. Therefore, this study investigated the effect of adding rejuvenator on physical and chemical properties of aged bitumen.The relationship between physical and chemical properties were also evaluated in this study. The physical property tests conducted were Penetration test, Softening Point (SP) test, Viscosity and Bending Beam Rheometer (BBR). The chemical property tests were Fourier Transform Infra-Red (FTIR) and Gas Chromatography-mass Spectroscopy (GC-MS). The oil-based rejuvenator namely cecabase was added with the variation of 0.3%, 0.5%, 0.7%, and 1.0%from the weight of bitumen. The result shows that the penetration increase and viscosity decrease with the additional cecabase. The SP and BBR tests show the inconsistent pattern. Through the FTIR test, the sulfoxide, carbonyl, and aromatic index ratio decrease while the aliphatic index increase with the increment of rejuvenator. This results proved that the aged bitumen undergo the rejuvenating process. The GC-MS test result shows that 0.7% rejuvenator content gave the same chemical components to bitumen control. The relationship between both properties shows that change in physical properties due to additional rejuvenator did not necessarily change the chemical properties of the respective bitumen.