Characterisation of a hybrid plant-based asphalt binder replacement with high reactive phenolic monomer content

ABSTRACT

The present study was undertaken to formulate a hybrid plant-based modifier to replace at least 20% of a non-polymer-modified asphalt binder (non-PMB). Different amounts of two types of lignin (L1 and L2) having high reactive phenolic monomer contents and a corn-based recycling agent (RCA) were shear-mixed with a PG 58-28 binder. Rheological properties of binder blends and those of neat PG 58-28 and PG 64-28 (PMB) were characterised. Also, their adhesion to granite and quartzite aggregates was evaluated. Furthermore, asphalt mixes containing neat PG 58-28 and that modified by different amounts of L1, L2, and RCA were produced and their resistance to cracking, rutting, and stripping was evaluated. While incorporating 25%L2 + 2%RCA in PG 58-28 was found to improve its resistance to rutting and thermal cracking, using 25% L1 caused excessive binder embrittlement. Incorporating L1, L2, or RCA in PG 58-28 was not found to have an adverse effect on binder-aggregate adhesion. Achieving a PG 64-28 binder (PMB) was found to be feasible by incorporating 25%L2 + 2%RCA in PG 58-28 binder while replacing 21.3% of virgin binder. Asphalt mixes containing L2 or a combination L2 + RCA exhibited resistance to cracking, rutting, and stripping which were higher than those of the control mix.

KEYWORDS:

• Biomaterials
• plant-based asphalt binder
• lignin
• recycling agent
• asphalt mix
• rheology
• cracking
• rutting
• moisture-induced damage

Acknowledgements

The help and comments received from Mr Steve Bly and Dr Alex McCurdy (POET LLC) are acknowledged. Authors would like to thank Dr Musharraf Zaman, Mr Kenneth Hobson, and Dr Syed Ashik Ali for their invaluable help. The contents of this article are the opinions of the authors and are not necessarily those of the sponsor.

Disclosure statement

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

Additional information

Funding

The study presented herein was conducted with financial support received from POET LLC [grant number SA1800512].