Evaluating the role of recycling rate and rejuvenator on the chemo-rheological properties of reclaimed polymer-modified binders

Abstract

Incorporating reclaimed asphalt (RA) in surface layer mixtures is still limited due to performance concerns, and it becomes even more challenging when combining aged polymer-modified bitumen (PMB) with virgin PMB. This study aims to evaluate, from a binder perspective, the feasibility of incorporating reclaimed polymer-modified binder (RPMB) in new surface layer mixtures. To address this challenge, blends of RPMB and virgin PMB were investigated at three replacement rates (20%, 40% and 60%) with and without a tall oil-based rejuvenator. First, the viscoelastic behaviour of the blends was assessed using a dynamic shear rheometer. Moreover, physicochemical changes were tracked using infrared spectroscopy and fluorescence microscopy. The experimental investigation revealed that, due to polymer degradation of the RMPB, only the blends with 20% RMPB exhibited polymer activity. Finally, the use of the rejuvenator compensated for the rheological properties of the aged RPMB and reduced the susceptibility to non-load-associated cracking.

KEYWORDS:

• Reclaimed asphalt binder
• recycling
• polymer-modified binder (PMB)
• rejuvenator
• polymer activity
• rheology

Acknowledgements

The authors would like to acknowledge Hilde Soenen from Nynas NV for her assistance on the fluorescence microscopy and her valuable comments. Also, Koen Deckers from BAM Contractors for providing the RA material.

Disclosure statement

No potential conflict of interest was reported by the author(s).