Tian Rongyan, Luo Haoyuan, Huang Xiaoming, Zheng Yangzezhi, Zhu Leyi, Liu Fengyang
School of Transportation, Southeast University, Nanjing 211189, China.
National Demonstration Center for Experimental Education of Road and Traffic Engineering, Southeast University, Nanjing 211189, China.
Materials (Basel). 2022 Mar 3;15(5):1889. doi: 10.3390/ma15051889.
To clarify the intrinsic relationship between the mechanical properties of asphalt and its fraction composition, the SARA fraction composition and six macroscopic mechanical properties (critical cracking temperature (TCR), fatigue life (Nf), non-recoverable creep (Jnr3.2), penetration, ductility, and softening point) were investigated for 16 asphalt samples. Fraction contents of asphaltene and aromatic are strongly correlated with TCR and ductility (R2 > 0.92) that characterize the ability of asphalt to adapt to deformation at low and medium temperatures. Heavy fraction (asphaltene and resins) content is also strongly correlated with (R2 > 0.90) penetration and Jnr3.2 that characterize the resistance of the asphalt to overall deformation at medium and high temperatures. To express the changes in the four fractions simultaneously with one indicator, a statistic, average deviation of the fractions between the given asphalt and its original (marked σ), is introduced in this study to characterize the degree of asphalt aging based on the fraction changes. It normalizes the four simultaneous change indicators (percentage of SARA fractions) during asphalt aging into one indicator. This new indicator has a strong correlation with several mechanical performance indicators of asphalt, where it is strongly correlated with TCR (R2 > 0.90), ductility, and penetration, which are also well correlated with Jnr3.2 (R2 > 0.85), Nf (R2 > 0.75), and softening point (R2 > 0.75).
