Evaluating the Bond Performance of Self-Consolidating Concrete in Prestressing Applications

This report presents the results from strand end-slip measurements and load tests on 73 pretensioned members that were fabricated at six different Precast/Prestressed Concrete Institute (PCI) producer member plants. Sixty-seven of these beams utilized standard production concrete mixes and placement techniques. As such, the data presented in this report are believed to be representative of standard industry practice between 2005 and 2008. This study revealed that the top-bar effect for pretensioned strands is primarily the result of a small amount of concrete above the strand, rather than a large amount of concrete below the steel. Accordingly, the findings of this investigation indicate that the current design assumptions for bond in pretensioned members are largely un-conservative for members with strands located near the top (as-cast) surface. This phenomenon can result in extremely large transfer lengths for strands located within a few inches of the top surface, including those in shallow members. In addition, the top-cast strand effect typically becomes more pronounced when concrete fluidity is increased. However, these same findings also revealed that the current design assumptions for bond were generally satisfied when strands were located deeper in the members. This was true for both flowable concrete and self-consolidating concrete mixtures.

• Record URL:
  http://www.ksdot.org/PublicLib/publicDoc.asp?ID=003808641
• 
• Summary URL:
  http://www.ksdot.org/PublicLib/publicDoc.asp?ID=003808643
• Supplemental Notes:
  • The appendices are not included with the final report; they are available on CD-ROM only by contacting library@ksdot.org.
• Corporate Authors:

  Kansas State University, Manhattan

  University Center for Transportation Research
  Department of Civil Engineering
  Manhattan, KS  United States  66506

  Kansas Department of Transportation

  Bureau of Materials and Research, 700 SW Harrison Street
  Topeka, KS  United States  66603-3745

  Precast/Prestressed Concrete Institute

  200 W Adams Street, #2100
  Chicago, IL  United States  60606-6938
• Authors:
  • Peterman, Robert J
  • Larson, Kyle H
• Publication Date: 2011-4

Language

• English

Media Info

• Media Type: Web
• Edition: Final Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 113p

Subject/Index Terms

• TRT Terms: Beams; Bond strength (Materials); Design; Load tests; Prestressed concrete; Self compacting concrete
• Uncontrolled Terms: Prestressing strands; Transfer lengths
• Subject Areas: Bridges and other structures; Highways; Materials; I24: Design of Bridges and Retaining Walls; I32: Concrete;

Filing Info

• Accession Number: 01341792
• Record Type: Publication
• Report/Paper Numbers: KS-10-3
• Files: TRIS, STATEDOT
• Created Date: Jun 1 2011 5:02PM