Chemical, morphological, and rheological properties of various rejuvenated asphalt binders

Abstract

Reclaimed asphalt pavement (RAP) material is considered as an economical approach for sustainable pavement construction. However, usage of higher RAP binder content is more susceptible to pavement cracking. Using rejuvenators with RAP binder is a widely used approach to address the issues related to RAP binder. This study used thin film oven test (TFOT) aged binder with three types of rejuvenators including waste cooking oil (UT/R1), modified waste cooking oil (TR/R2), and Hydrolene (HL/R3). Also, in some cases, styrene butadiene styrene (SBS) polymer was added with UT/R1 and TR/R2 rejuvenated binders to compare the performances. To understand the behavior and the performance of these rejuvenators, three sets of characterization tests were conducted: chemical, morphological, and rheological. Gas Chromatography-Mass Spectroscopy (GC-MS) and Fourier Transformed Infrared Spectroscopy (FTIR) was employed for chemical characterization, while Atomic Force Microscopy (AFM) was used for morphological analysis. Later, a frequency sweep test and surface free energy (SFE) test was conducted to understand the rheological performances and moisture damage resistance of rejuvenated asphalt binders respectively. Based on the experimentation, the study reveals that UT/R1 softens the binders most, whereas TR/R2 rejuvenator eliminates these issues and showed better rheological performances of the binder. However, in case of moisture susceptibility, TR/R2 rejuvenated binder seems to have poor resistance and the highest resistance was recorded for UT/R1 rejuvenated binders. This study observes a good correlation between chemical, morphological and rheological performances of binders which are expected to contribute to the performance evaluation and characterization of rejuvenated asphalt mixes.