Abstract
This study aimed to explore the long-term aging influence on chemo rheological properties and develop novel consecutive models for the long-term aging reaction kinetics of bitumen. The results revealed that the aging index was significantly dependent on the types of selected parameters. The Zero-order model was suitable to describe the long-term aging reaction kinetics of bitumen based on the oxygen containing functional groups with the reaction rate constants in 0.7–3.3*10−4 (mol L−1·h−1). In the SARA-based consecutive reaction model, the most optimum kinetics model for aromatic fraction was the Third-order reaction model and the corresponding reaction kinetics constant (k1) was 0.02 (mol·L−1)−2(h)−1. The Zero-order model could well fit the generation kinetics of asphaltene molecules with the reaction rate constant k2 of 3.85*10−4 mol·(L·h)−1. Further, the transformation reaction from the resin to asphaltene molecules was the control step of the whole consecutive reaction model. In this study, when one-unit resin fraction was generated, the consumption amount of aromatic fraction was about 2.82 units. Meanwhile, when one-unit resin fraction was consumed, only 0.58-unit asphaltene could be generated. The developed reaction kinetics models could be beneficial to predict the functional groups distribution and SARA fractions in aged bitumen with different aging degrees.
Original language | English |
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Article number | 2024188 |
Pages (from-to) | 1-16 |
Number of pages | 16 |
Journal | International Journal of Pavement Engineering |
Volume | 24 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2022 |
Keywords
- Long-term aging
- SARA fractions
- chemo-rheological characterization
- consecutive kinetics model
- quantitative conversion relationship