Another look at the use of modulated differential scanning calorimetry to study thermoreversible aging phenomena in asphalt binders: Fid-Bau Portal

Another look at the use of modulated differential scanning calorimetry to study thermoreversible aging phenomena in asphalt binders

Ding, Haibo / Hesp, Simon A.M.

Abstract

Highlights • Asphalt binders are either compatible single or incompatible multiphase systems. • Incompatibility is easily detected with modulated differential scanning calorimetry. • Phase incompatibility is associated with wax contaminants. • Incompatible asphalt binders suffer from thermoreversible aging.

Abstract Thermoreversible aging of asphalt is an important attribute that affects durability of flexible pavements. Compared to irreversible, oxidative hardening, the reversible aging effect due to the presence of wax and other contaminants is often overlooked by producers and users alike. Understanding how thermal history affects microstructure will allow producers and users of asphalt to improve durability. To this end, several asphalts were investigated with modulated differential scanning calorimetry, showing that aging strongly depends on composition and particularly wax content. The formation of equilibrium structures follows generic Avrami and Ozawa theories of crystallization, and mainly involves solid-to-solid transformations rather than gross phase separation. Binders produced from oil sands-derived crude oil from Alberta, Canada, enjoy low wax contents. Their more widespread use would benefit overall life cycle costs and thereby improve the sustainability of the road building industry.