Bond and Development of Deformed Square Reinforcing Bars

Square deformed reinforcing bars were widely used in concrete building and bridge construction before the adoption of ASTM A 305-50, which standardized geometry, spacing requirements, weight and deformation height. Although bond stress and development lengths for deformed square bars have traditionally been computed as equivalent round bars of equal cross-sectional area and weight, this approach has not been validated. This study presents data from archival research on deformed square and circular reinforcing bars both prior and subsequent to adoption and implementation of ASTM A 305-50 that provides information for assessment of bond and development of deformed square reinforcing bars in vintage and historic structures. Pullout test results show that deformed square bars exhibited average bond stress similar to those of round deformed bars. Treatment of deformed square bars as equivalent round bars for calculation of development length appears reasonable and conservative based on the findings from this study. Directions for future research are suggested.

  • Availability:
  • Authors:
    • Howell, Daniel A
    • Higgins, Christopher
  • Publication Date: 2007-5


  • English

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Filing Info

  • Accession Number: 01051277
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 31 2007 12:52AM