Comparison of Fresh Concrete Air Content Test Methods & Analysis of Hardened Air Content in Wisconsin Pavements

This research consisted of two phases: the first was a field study on the air void systems in Wisconsin pavements, and the second was a laboratory study to find the root causes of the problem identified in the field study. The first phase gathered sufficient measurements to verify the occurrence of disparities in air content measurements that had been anecdotally reported over the past few years. The research involved visiting twelve paving projects across Wisconsin in the construction season of 2014 to conduct field tests on fresh concrete and to gather samples for hardened air void analysis. Later drilled cores were taken from the pavement at approximately the same location as the samples. The results show that the pressure meter and ASTM C457 measurements of concrete cylinders were in reasonable agreement. The differences between air content measurements by the two methods were within ± 2 percentage points. In pavements where synthetic air entraining agents (AEAs) were used, the C457 air contents of sampled cylinders were in many cases significantly lower (up to about 5 air content percentage points) than that of drilled cores taken at approximately the same location. In pavements where neutralized vinsol resin (NVR) was used, air contents in the cylinders were similar or slightly greater than those in the cores. The second phase of the research was aimed at finding the root cause of the air content discrepancy observed in concrete made using synthetic AEAs. A laboratory program at multiple scales including concrete air void analysis, the foam drainage test, and fundamental tests for micro-properties of individual bubble shells was conducted. The results showed that the air bubbles in concrete entrained with synthetic AEAs were less robust than those with NVR and thus less able to survive during concrete sampling procedures for pressure air content.

• Record URL:
  https://wisconsindot.gov/documents2/research/0092-14-05-final-report.pdf
• 
• Summary URL:
  https://wisconsindot.gov/documents2/research/0092-14-05-research-brief.pdf
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/40773
• Corporate Authors:

  University of Wisconsin, Madison

  Department of Civil and Environmental Engineering
  1415 Engineering Drive
  Madison, WI  United States  53706

  Wisconsin Department of Transportation

  Research and Library Unit
  Madison, WI  United States  53707

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Pham, Le
  • Cramer, Steven
• Publication Date: 2019-2

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; References; Tables;
• Pagination: 92p

Subject/Index Terms

• TRT Terms: Air content; Air entraining agents; Air voids; Concrete pavements; Core samples; Fresh concrete
• Uncontrolled Terms: Hardened concrete; Vinsol resin
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 01702424
• Record Type: Publication
• Report/Paper Numbers: WHRP 0092-14-05
• Contract Numbers: WisDOT SPR# 0092-14-05
• Files: NTL, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Apr 22 2019 5:38PM