Asphaltene agglomeration through physical-chemical and rheological testing

Abstract

A better understanding of the changes in binder chemistry and microstructure triggered by aging is fundamental as it increases the cracking susceptibility of asphalt materials and reduces pavement durability. In this context, this paper presents the findings of a collaborative study that delves further into the alterations in binder chemistry, microstructure, and rheology of laboratory – and field-aged binders using innovative experimental and fundamental theory techniques. An increase in polarity leading to a shift in the apparent molecular weight distribution (AMWD) towards higher molecular weights, which implies molecular agglomerations, could be observed as a result of aging via Saturates, Aromatics, Resins, and Asphaltene Determinator (SAR-AD) and Size Exclusion Chromatography (SEC), respectively. As for the theoretical methods, the δ-method and Molecular Agglomeration Index (MAI) that estimate the AMWD and incidence of molecular agglomeration, respectively, show satisfactory relationship with the SAR-AD and SEC results. This reinforces the soundness of the δ-method and MAI.

KEYWORDS:

• Asphalt binder
• aging
• rheology
• binder composition
• molecular weight distribution

Acknowledgments

The authors gratefully acknowledge the French National Research Agency (ANR) funding this study under the MOVEDVDC project (ANR-17-CE22-0014). Also, the authors would like to thank Nadège Buisson (UGE), Christopher Seago (WRI), and Alex Literati (WRI) for providing the experimental data for the analyses presented in this paper.

Disclosure statement

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

Additional information

Funding

This work was supported by Agence Nationale de la Recherche: [Grant Number ANR-17-CE22-0014].