Assessing ConnDOT's Portland Cement Concrete (PCC) Testing Methods - Final Report

This report presents results of a study to assess Connecticut Department of Transportation's (ConnDOT's) portland cement concrete (PCC) testing methods. The study was designed in order to investigate why some cured PCC specimens did not attain required 28-day strengths, although investigations of these low-strength test results revealed that many in-place PCC strengths were actually acceptable. Statistical analyses of historical data were performed with SPSS® software to identify when low-strength test results occur most often, and what PCC mix types are most problematic. Results showed that PCC rejections occur most often, on a percentage basis, during the summer months, and that higher strength mix types (≥ 3500 psi) are most problematic. Next, researchers made and cured test specimens side-by-side with construction inspectors to assess testing methods. Temperature and maturity probes were embedded in 6" x 12" cylindrical specimens to monitor curing. Based upon observations and data collected in the field, the author presents theories as to why PCC specimens did not attain specified strengths. The concrete maturity method for estimating strength was evaluated, and temperature profiling was performed with maturity kits. These included three different devices: Engius' intelliRock™ II, Transtec Group's Pocket Command Cener™ Kit, and International Road Dynamics' (IRD) Concrete Maturity Monitor; which were compared to determine which, if any, is most appropriate for ConnDOT applications. The maturity method was also used to look at hot-weather concreting, cold-weather concreting and mass concreting operations.

Language

  • English

Media Info

  • Media Type: Print
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 130p

Subject/Index Terms

Filing Info

  • Accession Number: 01049508
  • Record Type: Publication
  • Report/Paper Numbers: 2244-F-06-8
  • Contract Numbers: CT Study No. SPR-2244
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: May 14 2007 8:46PM