Characterization of Crack Growth Rate of Sulfur-Extended Asphalt Using Cyclic Semi-Circular Bending Test

Characterizing crack propagation of asphalt mixtures is helpful for optimizing mixture design and predicting cracking performance of asphalt pavements. This paper develops a new method based on the cyclic semi-circular bending test to characterize crack growth rate of asphalt mixtures. Compared with other fatigue tests, a cyclically-loaded semi-circular test has the advantages of simple specimen geometry and high efficiency of sample preparation. To accurately capture crack length for determining crack growth rate, a digital image correlation is used, and crack mouth opening displacement is measured by linear variable differential transformers mounted on the surface of the specimen. Correlations between crack length and crack mouth opening displacement are established, which are used to determine crack lengths corresponding to loading cycles over the testing process. The proposed cyclic semi-circular bending test successfully characterizes the Paris’s law coefficients of sulfur-extended asphalt mixtures. The cyclic semi-circular bending test provides substantially lower coefficients of variance in terms of cycles to fatigue failure compared with other traditional fatigue tests such as the bending beam fatigue test and the Texas Overlay Test. Test results were used to determine the impact of sulfur content on fatigue life with the conclusion that a low level of sulfur added in the case of 15% change the rheology (softener) of the asphalt to the degree that more damage is caused in a controlled-stress mode loading. However, an increase in sulfur content (30% and 45%) apparently produces a stiffer mixture that is more resistant to damage and is comparable to the control mixture.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK50 Standing Committee on Structural Requirements of Asphalt Mixtures.
• Authors:
  • Zhang, Jun
  • Sakhaeifar, Maryam
  • Little, Dallas N
  • Bhasin, Amit
• 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
• Features: Figures; Photos; References; Tables;
• Pagination: 17p

Subject/Index Terms

• TRT Terms: Asphalt mixtures; Cracking; Flexural strength; Pavement cracking; Sulfur asphalt
• Uncontrolled Terms: Semicircular bending test
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 01661494
• Record Type: Publication
• Report/Paper Numbers: 18-03298
• Files: TRIS, TRB, ATRI
• Created Date: Feb 28 2018 9:26AM