Experimental and Analytical Evaluations of Confinement Reinforcement in Pretensioned Concrete Beams

The "AASHTO LRFD Bridge Design Specifications" require that confinement reinforcement be placed around prestressing strands in the bottom bulb of pretensioned concrete beams. Although the AASHTO specifications contain prescriptive requirements for the quantity and placement of confinement reinforcement, the effect of such reinforcement on end region behavior is not well understood. To evaluate the function and effect of confinement reinforcement, 12 tests were conducted on precast pretensioned beams loaded in three-point bending at a shear span-to-depth ratio of 1.0. Variables in the test program included strand size, strand quantity, prestressing force, and the presence or lack of confinement reinforcement. In the tests, the confinement reinforcement neither prevented nor delayed strand slip but improved shear capacity and displacement ductility and prevented splitting failure. Experimental results also indicated transverse strain in the concrete above the bearing pad, which eventually led to splitting failure in test beams without confinement reinforcement. An elastic finite element analysis of the test beam was conducted to model the strain distributions in the test beams before cracking. Results from the analyses matched well with the experimental results. In particular, the magnitude and distribution of the transverse concrete strain measured at the end of the beam agreed well with the experimental results.

• Record URL:
  https://doi.org/10.3141/2251-06
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=Experimental+and+Analytical+Evaluations+of+Confinement+Reinforcement+in+Pretensioned+Concrete+Beams&author=B.+Ross&author=H.+Hamilton&author=G.+Consolazio&publication_year=2011
• Availability:
  • Find a library where document is available. Order URL: http://www.trb.org/Main/Blurbs/166628.aspx
• Authors:
  • Ross, Brandon E
  • Hamilton, H R (Trey)
  • Consolazio, Gary R
• Publication Date: 2011

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 59-67
• Monograph Title: Structures 2011
• Serial:
  • Transportation Research Record: Journal of the Transportation Research Board
  • Issue Number: 2251
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Beams; Deformation curve; Ductility; Finite element method; Laboratory tests; Material reinforcement; Precast concrete; Pretensioning; Shear strength
• Identifier Terms: AASHTO LRFD Bridge Design Specifications
• Uncontrolled Terms: Confinement; Prestressing strands; Shear capacity
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01340801
• Record Type: Publication
• ISBN: 9780309167710
• Report/Paper Numbers: 11-0643
• Files: TRIS, TRB, ATRI
• Created Date: May 24 2011 2:57PM