STRUCTURAL LIGHTWEIGHT CONCRETE PRESTRESSED GIRDERS AND PANELS

This report explores the uses of high performance lightweight concrete (f'c >/= 6000 psi) in pretensioned girders and deck panels. A summary of pertinent literature on application of lightweight concrete in bridge applications is given. The results indicate a number of successful applications as well as a few cautions. The development of 6000 psi and 7500 psi mixes using locally available materials and local precasting plants is outlined. Results indicated that 7500 psi was a highly dependable maximum. Workability of the mixes was adequate, and a series of beam sections, including some purposefully highly congested members, were successfully cast under plant conditions. When applied in pretensioned girders, the transfer length for 1/2-in. strands was found to be 40% longer than the AASHTO requirement. Development lengths, moment capacities, and load-deflection curves were very similar to those of normal weight concrete girders. Lightweight concrete use in precast deck panels indicated the transfer length of smaller strands was adequate. The full calculated ultimate moment capacity of girders with lightweight concrete deck panels was developed. Such panels could be used interchangeably with normal weight concrete panels using current design requirements as long as the flexural tensile stress limits under fluid deck load are satisfied. The report recommends that AASHTO change the model for calculating development length for prestressing strand to an expression containing the concrete modulus of elasticity. This would make it applicable to both normal weight and lightweight concrete. A future report will discuss economic analysis factors.

• Record URL:
  • http://www.utexas.edu/research/ctr/pdf_reports/1852_1.pdf
• 
• Supplemental Notes:
  • Date published: September 2001; Revised: January 2002.
• Corporate Authors:

  University of Texas, Austin

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

  Texas Department of Transportation

  Research and Technology Implementation Office, P.O. Box 5080
  Austin, TX  United States  78763-5080

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Thatcher, D B
  • Heffington, J A
  • Kolozs, R T
  • Sylva III, G S
  • Breen, J E
  • Burns, N H
• Publication Date: 2002-1

Language

• English

Media Info

• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 208 p.

Subject/Index Terms

• TRT Terms: Bridge decks; Compressive strength; Girders; High performance concrete; Lightweight concrete; Literature reviews; Modulus of elasticity; Panels; Prestressed concrete; Pretensioning; Workability
• Uncontrolled Terms: Development lengths; Load deflection curves; Moment capacities; Prestressing strands
• Subject Areas: Bridges and other structures; Design; Highways; Materials; I24: Design of Bridges and Retaining Walls; I32: Concrete;

Filing Info

• Accession Number: 00941308
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-02/1852-1,, Research Report 1852-1
• Contract Numbers: Project No. 0-1852
• Files: TRIS, USDOT, STATEDOT
• Created Date: Apr 9 2003 12:00AM