Effect of I-FIT Configuration on Test Results of Asphalt Mixtures

The Illinois Flexibility Index Test (I-FIT) was developed to provide a practical and reliable parameter for the evaluation of asphalt concrete (AC) fracture resistance. The flexibility index (FI) can capture the behavior of AC in terms of their ductile or brittle fracture propagation. Through the evaluation of fracture energy and the post-peak slope of the load-displacement curve, the FI is capable of detecting variations in the overall resistance of AC against crack propagation. To ensure a reliable test, potential sources of variability should be investigated as part of the test development. The differences related to equipment settings, including the loading system and fixture components, are among the potential sources of variability. This paper presents results from the machine comparison study, carried out in relation to the use of different I-FIT devices. Three different combinations of devices were compared using eight different AC mixes. A statistical analysis was implemented on the test results to evaluate if any significant differences could be highlighted among average FI values given by each machine. The tests covered eight AC mixes using three I-FIT machines; results did not show any significant difference among the devices. In particular, the loading system and the support fixture did not influence FI results.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK50 Standing Committee on Structural Requirements of Asphalt Mixtures.
• Authors:
  • Barber, Edoardo
  • Ozer, Hasan
  • Al-Qadi, Imad L
  • Okte, Egemen
  • Zhu, Zehui
  • Wu, Shenghua
• 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: References;
• Pagination: 5p

Subject/Index Terms

• TRT Terms: Alternatives analysis; Asphalt concrete; Asphalt mixtures; Concrete tests; Cracking; Flexibility; Fracture mechanics; Fracture properties; Laboratory tests; Mix design; Statistical analysis; Test procedures
• Identifier Terms: Illinois Flexibility Index Test
• Subject Areas: Highways; Materials; I30: Materials;

Filing Info

• Accession Number: 01664175
• Record Type: Publication
• Report/Paper Numbers: 18-04746
• Files: TRIS, TRB, ATRI
• Created Date: Mar 26 2018 9:18AM