DESIGN OF POST-TENSIONED GIRDER ANCHORAGE ZONES

Several large thin-webbed box girders, with post-tensioned anchorage zones designed in accordance with AASHTO and ACI requirements, have experienced large cracks along the tendon path in the anchorage zones at the design stressing load. Cracking of this nature provides a path for penetration of moisture and salts and thus presents a potential corrosion and frost damage threat. In addition, such cracking negates a major reason for the use of prestressed concrete, the minimization of service load cracking. This report summarizes the major design-related observations and conclusions from an extensive analytical and experimental program which studied anchorage zone behavior of post-tensioned box girders. The experimental program investigated the primary variables affecting the formation of the tendon path crack: tendon inclination and eccentricity, section height and width, tensile splitting strength of the concrete, anchor width and geometry, and the effect of supplementary anchorage zone reinforcement, both active and passive. An extensive series of three-dimensional linear elastic finite element computer analyses was used to generalize these results and develop a failure theory to explain tendon path crack initiation based upon specified peak spalling strains at the edge of the anchorage. The theory agreed well with the experimental data over a wide spectrum of variables. (FHWA)

  • Corporate Authors:

    University of Texas, Austin

    Center for Transportation Research, 3208 Red River Street
    Austin, TX  United States  78705

    Texas State Department of Highways & Public Transp

    P.O. Box 5051
    Austin, TX  United States  78763

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Stone, W C
    • Breen, J E
  • Publication Date: 1981-6

Media Info

  • Pagination: 158 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00345088
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/TX-81/14+208-3FFinal Rpt., Res Rpt. 208-3F, FCP 45F3-722
  • Contract Numbers: Res Study 3-5-77-208
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Jan 29 1982 12:00AM