Analysis of nanoscale microstructures in asphalts of different aging states

Yuhong Wang, Kecheng Zhao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)

Abstract

Asphalt surface features revealed in the tapping-mode atomic force microscope (AFM) have been extensively studied. Most of the existing studies focus on the so-called bee-shaped surface feature, believed to be made of paraffin wax crystals. In the research reported in this paper, five asphalts of widely different aging states and asphaltenes obtained from two of these asphalts were examined by using an AFM in tapping mode. Two types of surface features were identified in all the specimens, as follows: (1) disk-shaped feature rising from the specimen surface, and (2) elliptical (and sometimes irregular) feature slightly recessed from the surface. In addition, a Strategic Highway Research Program (SHRP) asphalt (AAD) was used to study the morphology of asphaltenes in wax-free asphalt. The analysis of the topography and phase images of the microstructures revealed by AFM suggests that the disk-shaped and elliptical microstructures may contain asphaltenes. The morphology of asphaltenes from the asphalt extracted from a 36-year-old pavement appears to match the hypothetical so-called island molecular structure.
Original languageEnglish
Article number04015090
JournalJournal of Materials in Civil Engineering
Volume28
Issue number1
DOIs
Publication statusPublished - 1 Jan 2016

Keywords

  • Aging
  • Asphalt
  • Deterioration
  • Flexible pavement

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Materials Science(all)
  • Mechanics of Materials

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