Structures.

Details

• Creators:
  Sharp, Stephen R. ; Ozyildirim, H. Celik
• Corporate Creators:
  Virginia Center for Transportation Innovation and Research
• Corporate Contributors:
  Virginia. Dept. of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Nondestructive tests
  • Reinforced concrete pavements
  • Ultrasonic waves
  • Concrete, Impact echo, Mechanical waves, NDE, Spectral
  • analysis of surface waves, Sonic echo, Impulse response, Ultrasonic
• Publication/ Report Number:
  FHWA/VCTIR 14-R8
• Resource Type:
  Tech Report
• Geographical Coverage:
  Virginia
• Corporate Publisher:
  Virginia. Dept. of Transportation
• Abstract:
  "This study evaluated various techniques that use mechanical waves for the evaluation of critical concrete properties, ; such as proper consolidation of the concrete during placement and strength development; changes in modulus; and the detection ; of cracks, voids, and delaminated regions. The methods evaluated were ultrasonic shear-wave tomography, ultrasonic pulse ; velocity, crosshole sonic logging, sonic echo-impulse response, spectral analysis of surface waves, and the use of an impact echo ; scanner on pavements and bridge structures. ; Ultrasonic shear-wave tomography can be successfully used to determine the major distressed areas in pavements. ; Crosshole sonic logging can detect voids in drilled shafts and can indicate concrete performance and quality. Sonic echo-impulse ; response can reliably detect voids but is not always able to establish a precise location because of the potential variability in wave ; velocity. However, it can still provide useful thickness or depth information. In addition, detection of distress is limited by the ; embedded length-to-diameter ratios of the foundation element being examined. The use of ultrasonic pulse velocity can improve ; the accuracy of sonic echo–impulse response measurements by providing the actual velocity of the concrete being evaluated. Use ; of the impact echo scanner can provide delamination data for structures with smooth surfaces. ; In addition to detecting the condition of the concrete elements, these methods can be used to help determine compliance ; with end-result specifications. Quality control and acceptance using end-result specifications requires at least three test results to ; determine variability, which can be easily obtained using nondestructive test methods. ; The results regarding spectral analysis of surface waves were promising, but additional validation work is required to ; determine the abilities of this technique to assess asphalt-overlaid concrete decks. ; This study showed that nondestructive mechanical wave methods can be successfully used in determining concrete ; quality and the extent of distress in concrete structures. The study recommended that these methods be used by the Virginia ; Department of Transportation for condition assessment. The next step is to continue collecting data on pavements and bridge ; structures using these techniques."
  More +
• Format:
  PDF
• Funding:
  99207
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27469/dot_27469_DS1.pdf
• File Type:
  [PDF - 5.28 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:9900b7f7bba798683830ee7015e0e97e9d2bf72e87c02c23fc198f76d6ff9308