THE EFFECT OF REPEATED LOADS ON SERVICEABILITY AND ULTIMATE STRENGTH OF CONTINUOUS BRIDGE GIRDERS UTILIZING TENSION ELEMENTS

The report describes the static and fatigue behavior of composite T-beams, using a combination of prestressed concrete tension elements and reinforcing bars as the tension reinforcement. Two static tests were conducted on two-span continuous composite beams, one being designed without considering moment redistribution at ultimate load and the other with an assumed 20% moment redistribution. Test results indicated similar behavior for both beams, and there was approximately 35% moment redistribution before failure. Repeated load tests were performed on six specimens producing a load in the tension elements varying from 0.77 Pcr to 1.63 P sub cr, where P sub cr is the load causing initial cracking of the tension elements. It was indicated that the use of multiple tension elements augmented with steel reinforcing bars increased the endurance limit of the composite beam to the cracking load level P sub cr, in contrast to the endurance limit of 0.7 P sub cr revealed by an earlier investigation using specimens reinforced with a single tension element. Repeated load tests were also performed on two additional specimens of equal ultimate moment capacity, one reinforced with tension elements exclusively, while the other reinforced with only reinforcing bars.

• Corporate Authors:

  North Carolina State University, Raleigh

  Raleigh, NC  United States  27695

  North Carolina Department of Transportation

  Raleigh, NC  United States 

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Mirza, J F
  • Zia, P
  • Rizkalla, S M
• Publication Date: 1975-9

Media Info

• Pagination: 139 p.

Subject/Index Terms

• TRT Terms: Bearing capacity; Fatigue limit; Fracture mechanics; Girders; Highway bridges; Prestressed concrete; Reinforcing materials; T beams; Ultimate strength
• Subject Areas: Bridges and other structures; Materials;

Filing Info

• Accession Number: 00176010
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: ERSD-110-73-2, FHWA/RD-78-S0700
• Files: NTIS, USDOT, STATEDOT
• Created Date: Jul 19 2002 12:00AM