Characterization of glass transition temperature and surface energy of bituminous binders by inverse gas chromatography

Inverse gas chromatography (IGC) was used to characterize two bituminous binders (A and B) of different origin. Glass transition temperatures (Tg) were determined by constructing van't Hoff plots using n-pentane probes in a temperature range between −50 °C and +120 °C. Tg values were specified using the first deviations from linearity observed in the adsorption zone of the plots. A 6 °C difference in Tg was found between the two different specimens. Retention measurements using n-alkane probes, carried out at −30 °C, revealed a higher dispersive surface energy term ( ) for bituminous binder A than for B, with values of 59.3 and 50.6 mJ/m2, respectively. Binder A was composed of a higher asphaltenes content compared to binder B. This difference in chemical composition accounted for the different surface energy values.