Extraction of polycyclic aromatic compounds (PAC) and the influence on the mechanical and chemical properties of asphalt binder

As a part of Aromatics fraction in asphalt binder, polycyclic aromatic compounds (PAC) is chemical group, including some different kinds of several thousand individual compounds, which have a negative impact on the environment and human health. PAC in asphalt binder is potentially hazardous due to volatile components and leakages; therefore measurements and analyses of PAC in asphalt binder are recommended. The common method of separating asphalt binders is impractical for the analysis of PAC, thus an innovative method is proposed. Four binders are studied with their short-term and long-term aged samples. Based on the measurement of the PAC and asphaltenes contents, effects of various aging processes on the components of PAC are investigated in this paper. Furthermore, the influence of PAC on the mechanical and chemical properties of binders is studied. The results show that the PAC exhibit significant differences before and after ageing processes. Compared with the asphaltenes compound, PAC has an opposing effect on the mechanical properties of asphalt binders. On the other hand, the chemical properties of PAC is studied to explore the mechanism of the softening effect. In addition, four binary functions with PAC and asphaltenes contents are established in this study.