Design, Fabrication, and Construction of Long-Span Precast Pretensioned Girders Made with 0.7" Diameter Strands

Long-span bridges are often used in environmentally sensitive terrains, water crossings, and in locations with traffic and geometrical restrictions. Bridges with long-span precast pretensioned girders are advantageous due to their ease and speed of construction, lower cost, and long-term durability. The applicability of current bridge design and construction specifications for longer span prestressed girders is uncertain. Introducing the 0.7″ strands will help bridge designers extend the spans of the current beam shapes as well as any future development. This larger strand helps by increasing the possible area of prestressing steel and by lowering the centroid of the prestressing force, which enhances the eccentricity of the force and effectiveness of the prestressing steel. Research is needed to examine the applicability of the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Design Factor (LRFD) Bridge Design and Construction Specifications for long-span precast pretensioned girders. This research shall thoroughly address design issues, fabrication, shipping, and handling of long-span precast pretensioned girders. To incorporate the 0.7″ strand in the AASHTO LRFD Bridge Design Specifications, research is needed to determine the transfer length, the development length, the strands spacing, and the minimum concrete release strength. The objective of this research is to summarize the current practice and augment the AASHTO LRFD Bridge Design Specifications (BDS) on the use of long-span precast pretensioned girders. The objective also includes developing specifications to incorporate the 0.7″ strands in the BDS. This research should include instrumenting long-span precast pretensioned girders during all phases of fabrication and construction and comparing the measured strain at the end zones, prestress losses, deflections, and cambers with the calculated values. This research addresses issues in several of the areas identified as program objectives in the 2013 Strategic Plan for Bridges and Structures developed by the AASHTO Highway Subcommittee on Bridges and Structures. The objectives addressed in this research are: Accelerate Bridge Delivery, Optimizing Structural Systems, and Maintaining and Advancing the AASHTO Specifications. Increasing the spanning capabilities of precast girders is expected to have a large impact on reducing the bidding cost of current superstructure options for long-span bridges as it will provide a competitive alternative to steel solutions.


  • English


  • Status: Proposed
  • Contract Numbers:

    Project 12-109

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Dekelbab, Waseem

  • Start Date: 20150805
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 40205

Subject/Index Terms

Filing Info

  • Accession Number: 01572345
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 12-109
  • Files: TRB, RiP
  • Created Date: Aug 6 2015 1:00AM