Thermal and kinetic analyses of pure and oxidized bitumens

The thermal behaviour of pure and oxidized bitumens was studied by both DSC from −60 to +80 °C and TGA at different heating rates in flowing nitrogen from 100 to 600 °C. The determined crystallised fractions FC of pure and oxidized bitumens were successively 5.19% and 3.90% and the determined glass transitions Tg of pure and oxidized bitumens were successively −41.43 °C and −28.36 °C. The kinetics parameters (n, k, Ea, A) were calculated from the experimental results using a differential method. The TGA/DTG data showed that the thermal degradation of bitumen is a one stage process for pure bitumen and a two stage process for oxidized bitumen.