A Comparative Evaluation of CoreLok Device in Determining Reliable Bulk Specific Gravity and Maximum Specific Gravity Test Results

Details

• Creators:
  Rajagopal, Arudi ; Crago, Dan
• Corporate Creators:
  University of Cincinnati. Dept. of Civil and Environmental Engineering ; American Association of State Highway and Transportation Officials
• Corporate Contributors:
  United States. Federal Highway Administration. Office of Research and Development ; Ohio. Dept. of Transportation
• Subject/TRT Terms:
  • Specific gravity
  • Hot mix paving mixtures
  • Sealing (Technology)
  • Air voids
  • Compaction
  • Confidence intervals
  • Statistical analysis
  • Test procedures
  • Testing
  • Testing equipment
  More +
• Publication/ Report Number:
  FHWA/OH-2007/07
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Ohio
• TRIS Online Accession Number:
  1053633
• Edition:
  Final Report
• Corporate Publisher:
  United States. Federal Highway Administration
• Abstract:
  This study was initiated to systematically compare the specific gravity values of laboratory compacted Hot Mix Asphalt (HMA) mixtures using American Association of State Highway and Transportation Officials (AASHTO) and vacuum sealing procedure (using CoreLok device). In this comparative evaluation program, a series of bulk and maximum specific gravity tests were conducted using CoreLok as well as AASHTO procedures on laboratory compacted HMA mixtures. The asphalt mixtures, aggregate types and compaction levels selected to prepare the samples truly represented Ohio's materials and construction practices. A thorough statistical analysis of the data was conducted. The test results revealed that the maximum specific gravity (G mm) values obtained by both the test procedures (CoreLok and AASHTO) are statistically similar at a confidence interval of 95%. The bulk specific gravity (Gmb) values obtained using the CoreLok test procedure are always lower than the AASHTO (Gbmb) values and the difference is statistically significant. It was also noted that, the difference in G sub mb values between the two procedures is statistically significant regardless of the type of mix, type of aggregate and compaction level. Air voids values estimated using the CoreLok device are always greater than corresponding AASHTO values. In general, the difference in air voids is 1-2% with a maximum of 4.5% for a gap graded mix. The difference in air void content obtained from the two procedures is statistically significant at 95% confidence interval. There could be potential advantages in specifying this device in terms of reduced testing time. If the Ohio Department of Transportation intends on using the CoreLok, it is recommended not to change its current specification which is based on historical data and instead use an appropriate correlation factor to relate the CoreLok and AASHTO values.
• Format:
  PDF
• Funding:
  134187
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/37641/dot_37641_DS1.pdf
• File Type:
  [PDF - 666.33 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:80ca21e6b8d431de5730092cdc977bdae73b529efb235de960c6f10dc05bdff4