Investigation of the aggregation behavior of rubber asphalt components induced by short-term Aging: A perspective from molecular dynamic simulations and microscopic tests
•Determine the short-term aging-induced morphological variation in the aggregation of different components of rubber asphalt.•Evaluate the property changes caused by component aggregation behavior before and after the short-term aging of rubber asphalt.•Clarify the microscopic mechanism of different...
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Veröffentlicht in: | Journal of molecular liquids 2024-11, Vol.414, p.126202, Article 126202 |
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Sprache: | eng |
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Zusammenfassung: | •Determine the short-term aging-induced morphological variation in the aggregation of different components of rubber asphalt.•Evaluate the property changes caused by component aggregation behavior before and after the short-term aging of rubber asphalt.•Clarify the microscopic mechanism of different components aggregation of rubber asphalt before and after short-term aging.
The distribution characteristics of different rubber asphalt components remain a subject of debate, particularly under the influence of asphalt short-term aging. This paper leverages the visualization advantages of molecular dynamics (MD) simulation and integrates them with microscopic testing methods to observe morphological variations and property changes in the aggregation of different components induced by short-term aging. Short-term aging of rubber asphalt is simulated using a thin-film oven test (TFOT). By conducting Fluorescence microscope (FM) and scanning electron microscope (SEM) tests, the aggregation behavior of components under changes in fluorescence phase and microstructure before and after short-term aging is revealed. MD simulation is employed to analyze the degree of aggregation between different components before and after short-term aging. SEM test results indicate that the structure becomes looser and forms distinct pits as the rubber asphalt ages. FM test results reveal that the particle size of rubber powder particles in aged rubber asphalt decreases and aggregates gradually. Concurrently, the asphalt phase in rubber asphalt becomes more uniform after aging. MD simulation results demonstrate significant aggregation between asphaltene-asphaltene molecules and asphaltene-rubber powder molecules in aged rubber asphalt. A higher degree of asphaltene aggregation leads to reduce asphalt penetration and increase softening point and viscosity. Furthermore, rubber powder molecular chains can inhibit “π-π stacking,” and “offset π-π stacking” of the asphaltene molecules. Therefore, the accumulation effect in aged rubber asphalt is mitigated compared with aged base asphalt. The research outcomes provided a foundation for further studies on the aging and rejuvenation of rubber asphalt. |
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ISSN: | 0167-7322 |
DOI: | 10.1016/j.molliq.2024.126202 |