THE HISTORY OF THE PRESTRESSING STRAND DEVELOPMENT LENGTH EQUATION. FINAL REPORT

A research study was conducted to determine the history of the AASHTO prestressing strand development length equation and to evaluate the significance, with respect to development length, of changes in the AASHTO provisions for the determination of steel stress at ultimate flexural strength. The accuracy of the AASHTO provisions in determining steel stress at ultimate flexural strength was also evaluated for a number of typical cross sections used in bridge construction. The strand development length equation was first introduced in the 1963 ACI Building Code and was adopted by AASHTO in 1973. The original research that formed the basis for the equation was conducted at the Portland Cement Association (PCA) in the late 1950s and early 1960s. ACI Committee 423 derived and proposed the development length equation based on a reappraisal of the PCA results. The intent of the committee in developing the development length equation was to come up with a "reasonable mean" for the data points rather than a conservative estimate. A comparison of calculated steel stress at ultimate flexural strength using AASHTO Equation 9-17 and compatibility analyses using the RESPONSE computer program indicated that for AASHTO I-beams, bulb-tees, and box sections with deck slabs, the results were within 5%. The differences were higher (up to 8%) in the cases of box beams without deck slabs (high reinforcement ratios) and prestressed concrete piles.

• Corporate Authors:

  Construction Technology Laboratories, Inc.

  5400 Old Orchard Road
  Skokie, IL  United States  60077-1030

  Federal Highway Administration

  Turner-Fairbank Highway Research Center, 6300 Georgetown Pike
  McLean, VA  United States  22101
• Authors:
  • Tabatabai, Habib
  • Dickson, T J
• Publication Date: 1995-2

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 112 p.

Subject/Index Terms

• TRT Terms: Accuracy; Bridges; Equations; History; Prestressing; Specifications; Steel; Stresses
• Uncontrolled Terms: Development length; Prestressing strands
• Old TRIS Terms: Ultimate flexural strength
• Subject Areas: Bridges and other structures; Design; Highways; History; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00675188
• Record Type: Publication
• Report/Paper Numbers: FHWA-RD-93-076, 2D1a3032
• Contract Numbers: DTFH62-92-C00040
• Files: TRIS, USDOT
• Created Date: Mar 3 1995 12:00AM