Using AFM to Study the Interaction Between Recycled Asphalt Materials and Virgin Asphalt Binders

This paper summarizes the results of a laboratory testing program that was conducted to examine the blending between recycled asphalt materials (recycled asphalt shingles (RAS) and reclaimed asphalt pavement (RAP) binders and virgin asphalt binders and to evaluate the factors that may affect fatigue cracking resistance of asphalt mixtures prepared using these materials. To this end, atomic force microscopy (AFM) was utilized to characterize the interfacial zone that develops between the tear-off recycled asphalt shingles RAS and a virgin asphalt binder and compare it to that develops between RAP and the same virgin asphalt binder. Several asphalt mixtures were used to evaluate the effect of the incorporation of RAS, RAP, and their combination on fatigue cracking resistance, including a control mixture (with no RAP or RAS), a mixture containing 30% RAP, a mixture containing 5% tear-off RAS, and a mixture containing 20% RAP and 3% tear-off RAS. The resistance of the asphalt mixtures to fatigue cracking was evaluated using the semi-circular bend (SCB) test. The AFM test results indicated that blending occurred between the RAP binder and the virgin binder. A reduction in the adhesive bonding energy was observed in the blending zone due to the presence of RAP. However, the adhesive bonding energy of the blending zone were significantly higher than those in the RAP binder. The AFM imaging and force spectroscopy experiments revealed no blending between tear-off RAS materials and the virgin asphalt binder considered. The SCB test results showed that the use of tear-off RAS in asphalt mixes significantly reduced their resistance to fatigue cracking.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK20 Standing Committee on Asphalt Binders.
• Authors:
  • Nazzal, Munir D
  • Holcombe, Evan
  • Kim, Sang Soo
  • Abbas, Ala
  • Kaya, Savas
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Pagination: 6p

Subject/Index Terms

• TRT Terms: Bituminous binders; Electron microscopy; Recycled materials
• Uncontrolled Terms: Atomic force microscopy; Interaction (Materials)
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 01661430
• Record Type: Publication
• Report/Paper Numbers: 18-04043
• Files: TRIS, TRB, ATRI
• Created Date: Feb 27 2018 9:46AM