Characterization of low temperature creep properties of crack sealants using bending beam rehometry.

Details

• Creators:
  Al-Qadi, Imad L. ; Yang, Shih-Hsien ; Elseifi, Mostafa A. ; Dessouky, Samer ; Loulizi, Amara ; Masson, Jean-Francois ; McGhee, Kevin K.
• Corporate Creators:
  University of Illinois at Urbana-Champaign. Department of Civil and Environmental Engineering
• Corporate Contributors:
  Louisiana State University (Baton Rouge, La.) ; University of Texas at San Antonio ; Reseau National Universitaire, Tunisia ; National Research Council Canada ; Virginia Transportation Research Council (VTRC) ; Virginia. Dept. of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Pavement design
  • Pavement components
  • Pavement cracking
  • Pavement layers Pavements
• Publication/ Report Number:
  FHWA-ICT-08-029;ICT-08-029, UILU-ENG-2008-2017
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  Crack sealing has been widely used as a routine preventative maintenance practice. Given its proper installation, crack sealants can extend ; pavement service life by three to five years. However, current specifications for the selection of crack sealants correlate poorly with field ; performance. The purpose of this research was to develop performance guidelines for the selection of hot-poured bituminous crack sealants at ; low temperature. In this part of the research, the creep behavior of crack sealant at low temperature is measured and performance criteria for ; material selection were developed. Because various pavement and State agencies are well acquainted with and own the Bending Beam ; Rheometer (BBR), which was developed during the Strategic Highway Research Program (SHRP), an attempt was made to utilize the same ; setup to test hot-poured bituminous-based crack sealants. Testing conducted in this research project indicated that the standard BBR was ; inappropriate for testing soft bituminous-based hot-poured crack sealant, even at -40°C. The measured deflection exceeded the BBR limit, for ; some sealants, after only a few seconds of loading. To address this issue, the moment of inertia of the tested beam was increased by doubling ; its thickness (from 6.35mm to 12.7mm). For the new beam dimensions, it was found that only 4% of the beam center deflection is due to shear, a ; value deemed acceptable for sealant evaluation and comparison. ; In an effort towards developing a robust testing procedure, 15 sealants from various manufacturers were included in the study and tested ; between –4°C and –40°C. In addition, five sealants, which have known field performance, were tested to validate the laboratory results and ; establish specification thresholds for the selection guidelines. Since stiffness calculation in the BBR test method requires that measurements be ; made within the linear region of viscoelastic behavior, validation of this theory was conducted for crack sealants. This was found to be generally ; the case with crack sealants, which allowed for the use of the time-temperature superposition. If the temperature-superposition principle is ; applied, the stiffness at 240s at a given temperature can be used to predict the stiffness after 5hr of loading at a temperature that is 6°C lower. ; With the assumption of linear viscoelastic behavior, sealants performance can be characterized through stiffness, average creep rate, and ; dissipated energy ratio. Stiffness was found to be sensitive to temperature changes and could be used to differentiate between sealants. The ; measurements of the average creep rate and the dissipated energy ratio were also found to be valuable in differentiating between sealants. In ; addition, numerical modeling was used to simulate the mechanical response of crack sealants at low temperatures. Parameters that may be ; used for evaluating crack sealant cohesive performance using the crack sealant BBR (CSBBR) are the stiffness at 240s, average creep rate, and ; the dissipated energy ratio. For simplicity, the first two parameters, stiffness at 240s and average creep rate, are recommended for ; implementation in the sealant performance grade. The recommended thresholds are maximum stiffness of 25MPa and minimum average creep ; rate of 0.31.
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• Format:
  PDF
• Funding:
  VTRC Project # 67775, TPF-5(045)
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/16706/dot_16706_DS1.pdf
• File Type:
  [PDF - 2.58 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:5324b55664ea6b44518bf000aee506ed4e13c025ea55fee47780f2b35da8853e28c390c5a8851fa0dce195769d861d87a732fb3262dcd697475562d3a91f3485