The Impact of Specimen Size and Void Content on the Impact Resonance Testing of Asphalt Concrete

Vibration based nondestructive testing is a useful tool for evaluating characteristics of asphalt concrete. The test is promoted because of its simplicity, repeatability, and ability to characterize asphalt concrete properties. The impact resonance (IR) method of test is among the common techniques for this purpose. The test results, however, are influenced by specimen size and testing configurations. A study was undertaken to evaluate the effect of specimen aspect ratio on the IR test results at a range of air voids and temperatures. Cylindrical laboratory compacted specimens of asphalt concrete were produced and processed through sawing and coring to deliver specimens of different sizes and aspect ratios. The test results, both in longitudinal and torsional modes, were generated in time domain and converted to frequency domain using Fast Fourier Transform. It was demonstrated that the test was highly repeatable and capable of producing results consistent with expected stiffness of the mix. Mixes at higher air voids and higher temperatures produced lower resonant frequencies and higher damping levels. It was found that the test results were significantly influenced by the specimen height as frequency was reduced with increase in the specimen height, even at the same aspect ratio (height/diameter). A threshold aspect ratio is defined, i.e. the length to diameter ratio beyond which the material response is not significantly influenced by the change in the specimen height (wave length travel path). It was verified this threshold aspect ratio depends on the specimen size and becomes smaller as the specimen diameter increases.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK50 Characteristics of Asphalt Paving Mixtures to Meet Structural Requirements. Alternate title: Impact of Specimen Size and Void Content on Impact Resonance Testing of Asphalt Concrete.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Boz, Ilker
  • Solaimanian, Mansour
• Conference:
  • Transportation Research Board 93rd Annual Meeting
  • Location: Washington DC
  • Date: 2014-1-12 to 2014-1-16
• Date: 2014

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 22p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Air voids; Asphalt concrete; Fast Fourier transforms; Nondestructive tests; Resonance; Specimens; Temperature
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01519288
• Record Type: Publication
• Report/Paper Numbers: 14-5176
• Files: TRIS, TRB, ATRI
• Created Date: Mar 24 2014 12:02PM