“…Previous studies have shown that the major functional groups produced during oxidation of asphalt are carbonyl groups (Dorrence et al, 1974), sulfoxides (Petersen et al, 1981), sulfones, and sulfates (Huang et al, 1995). Because of its capability, simplicity, and rapidness, GPC has been used to characterize petroleum products (Richardmond, 1967;Haley, 1971;Kiet et al, 1977Kiet et al, ) since 1960 In the characterization of asphaltic materials by GPC, the effect of molecular weight on the glass transition temperature of asphalt has been reported (Huynh et al, 1978). Also, GPC has been used to correlate the molecular size distributions to the performance of asphalts (Jennings, et al, 1981 1982) .…”