Bitumen fractionation: Contribution of the individual fractions to the mechanical behavior of road binders. (15th February 2021)

• Record Type: Journal Article
• Authors: Chailleux, Emmanuel; Queffélec, Clémence; Borghol, Ilef; Farcas, Fabienne; Marceau, Sandrine; Bujoli, Bruno
• Is Part Of: Construction & building materials. Volume 271(2021)
• Publication Date: 2021-02-15
• Subjects: Bitumen -- Fractionation -- Rheological behavior -- GPC -- Asphaltenes -- Maltenes -- DSC; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.121528
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Bitumen UV absorbance is a linear sum of SARA fraction absorbance. Bitumen glass transition is a combination of glass transition of maltene fractions. A majority of the bitumen crystallizable fractions are in the less polar fraction. Asphaltenes structures the overall rheological properties of bitumen. Saturated fraction gives the overall viscous properties even at low temperatures. Abstract: Anticipation of alternative road binder to replace petroleum derived bitumen requires a deep understanding of relationships between the chemical composition of bitumen and their physical properties, especially rheological ones. The vast number of the different molecules constituting bitumen is too complicated to unravel, thus in this paper we propose to fractionate bitumen into four fractions and study their different physico-chemical properties. The melting temperature and the glass transition of each fractions was determined by DSC while their molecular weight distribution was determined by HS-SEC. Finally, their rheological properties were investigated by DSR. This study highlighted the importance of all bitumen phases: the less polar liquid phase driving the viscous behavior up to −50 °C, the more polar solid phase responsible of the thermal stability and the stiffness, and finally the intermediate viscous oily phases allowing the molecular weight distribution continuity and by consequence allowing to have, on a large temperature range, a viscous liquid behavior at high temperature or low frequency, and an elastic stiff behavior at low temperature. Crystallizable fractions and asphaltene aggregates seemed to act as key molecular structures in the continuous phase.