Molecular dynamics evaluation of activation mechanism of rejuvenator in reclaimed asphalt pavement (RAP) binder

Incorporation of rejuvenators can promote the rejuvenation of heavily oxidized asphalt when high proportion of reclaimed asphalt pavement (RAP) is used. However, there are few atomic-scale interpretations on the rejuvenating effect of rejuvenator in RAP and its activation mechanism during the blending of aged and virgin asphalt. This study focuses on the atomic modeling of rejuvenation behavior of oxidized asphalt. Three types of asphalt models (virgin, aged, and rejuvenated asphalt) were constructed respectively for comparative analyses of thermodynamics, glass transition behavior, free volume, self-diffusion, and atomic structures. The mutual-diffusion model of virgin and RAP asphalt was further assembled for the activation investigation of rejuvenator. Results denote a 4.43% increment of free volume and an 11.82 °C decrease of glass transition temperature in aged asphalt is observed after blending with 10% rejuvenators. Rejuvenators increase the cohesion of RAP binder to improve its cracking resistance, and the diffusivity of aged asphalt is restored to more than 68% with 10% selected rejuvenators. The introduction of rejuvenators promotes de-agglomeration to asphaltenes, which is a measure of the true rejuvenation of oxidized asphalt and is aligned with previous studies. The mixing efficiency of aged and virgin asphalt is boosted by imparting higher activity to macromolecules (such as asphaltenes and resins) when using rejuvenators. Insights for the option of rejuvenators at molecular scale as well as the optimization of asphalt composition can be provided from energy perspective.

• Record URL:
  https://doi.org/10.1016/j.conbuildmat.2021.123898
• Record URL:
  http://www.sciencedirect.com/science/article/pii/S0950061821016585
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09500618
• Supplemental Notes:
  • © 2021 Elsevier Ltd. All rights reserved. Abstract reprinted with permission of Elsevier.
• Authors:
  • Liu, Jinzhou
  • Liu, Qi
  • Wang, Shuyi
  • Zhang, Xiaoyu
  • Xiao, Chuanyu
  • Yu, Bin
• Publication Date: 2021-9-6

Language

• English

Media Info

• Media Type: Web
• Features: Figures; Illustrations; References; Tables;
• Pagination: 123898
• Serial:
  • Construction and Building Materials
  • Volume: 298
  • Issue Number: 0
  • Publisher: Elsevier
  • ISSN: 0950-0618
  • Serial URL: http://www.sciencedirect.com/science/journal/09500618?sdc=1

Subject/Index Terms

• TRT Terms: Activation (Chemistry); Reclaimed asphalt pavements; Rejuvenators; Thermal properties
• Identifier Terms: Molecular Dynamics (Software)
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 01776893
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 23 2021 3:23PM