Carbon-13 molecular structure parameters of RTFOT aged asphalts: Three proposed mechanisms for aromatization.

The determination of average molecular structural parameters of asphalts re presents an important step in describing their skeleton. Using a new method based only on the analysis of carbon-13 nuclear magnetic resonance measure ments, the average molecular parameters were determined for three asphalts before and after Rolling Thin Film Oven Test aging. From the analysis of th e changes in the parameters, three mechanisms are proposed to explain the a romatization process in asphalts during oxidation.