POST-TENSIONED BRIDGES ARE PICK OF THE POSSIBLES. PART 1

This first part of a two-part article describes the construction of post-tensioned bridges at three sites. (1) the Parrotts Ferry Bridge, California, has three spans, the main central one being 640 feet, to facilitate construction of the bridge with balanced cantilevers from each pier using travelling falsework carriages. Details are included of the placing and stressing of the thread bars and strand tendons used in the structure. (2) The project at Vail Pass, Colorado, includes four post-tensioned segmental box girder bridges (one four-span, three three-span). The article records the design and construction alternatives, and post-tensioned segmental construction was selected, both segments and piers being cast in situ. The concrete composing the structure was coloured to match surrounding earth rocks. A description is given of the travelling forms and support truss together with the sequence of concreting and post tensioning operations. A super plasticiser was used in the concrete to ensure early strength. A summary is included of the three-day cycle of segment construction and stressing. (3) The Long Key Bridge, Florida is 2.3 miles long and consists of 101 spans built by post-tensioned segmental construction. Possible alternative designs are tabulated. Details are given of specifications for concrete and reinforcement with options allowed for span construction method. The span by span erection method used a temporary steel assembly truss in conjunction with a barge-mounted crane. The sequence of assembly operations is explained, and a description given of the stressing tendons and their location. Mention is made of the use of dry joints between the segments. For part 2 of this article see TRIS no 310290. (TRRL)

  • Availability:
  • Corporate Authors:

    Cement and Concrete Association

    Wexham Spring
    Slough SL3 6PL, Buckinghamshire,   England 
  • Publication Date: 1979-9

Media Info

  • Features: Figures; Photos; Tables;
  • Pagination: p. 12-16
  • Serial:
    • CONCRETE
    • Volume: 13
    • Issue Number: 9
    • Publisher: THE CONCRETE SOCIETY
    • ISSN: 0010-5317

Subject/Index Terms

Filing Info

  • Accession Number: 00310289
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jul 22 1980 12:00AM