A STUDY OF I-SECTION, PRESTRESSED CONCRETE GIRDERS SUBJECT TO TORSION, SHEAR, AND BENDING

AVAILABLE DATA AND THEORIES CONCERNING THE DIAGONAL TENSION CRACKING OF PRESTRESSED CONCRETE MEMBERS SUBJECT TO COMBINED TORSION, SHEAR AND BENDING ARE REVIEWED, AS ARE THOSE CONCERNING THE ULTIMATE STRENGTH OF PRESTRESSED CONCRETE MEMBERS SUBJECT TO COMBINED TORSION AND BENDING. A TWO PART STUDY OF THE BEHAVIOR OF PRESTRESSED CONCRETE I-SECTION GIRDERS IS REPORTED; PART A IS CONCERNED WITH DIAGONAL TENSION CRACKING IN GIRDERS SUBJECT TO COMBINED TORSION, SHEAR AND MOMENT; PART B IS CONCERNED WITH THE ULTIMATE STRENGTH OF GIRDERS SUBJECT TO COMBINED TORSION AND MOMENT. TWENTY FULL-SCALE I-SECTION GIRDERS WERE TESTED. THE PRIMARY VARIABLES IN PART A WERE THE RATIO OF TORSIONS TO SHEAR AND THE SHEAR SPAN; AND IN PART B WERE THE STIRRUP SPACING AND THE AMOUNT OF ADDITIONAL UNPRESTRESSED LONGITUDINAL REINFORCEMENT. PROCEDURES ARE DEVELOPED FOR THE CONSTRUCTION OF TORSIONSHEAR INTERACTION DIAGRAMS FOR DIAGONAL TENSION CRACKING, WHICH REFLECT ACTUAL GIRDER BEHAVIOR WITH REASONABLE ACCURACY. THE PROVISION OF ADDITIONAL LONGITUDINAL REINFORCEMENT WAS FOUND NOT TO INCREASE THE ULTIMATE STRENGTH OF GIRDERS OF THIS TYPE SUBJECT OT COMBINED TORSION AND FLEXURE, DUE TO PREMATURE SPLITTING OF THE OUTSTANDING PARTS OF THE COMPRESSION FLANGE. AT SERVICE LOADS THE TORSIONAL AND FLEXURAL STIFFNESS OF THE GIRDERS WERE NOT REDUCED BY COMBINED LOADING AND COULD BE CALCULATED WITH REASONABLE ACCURACY USING THE ELASTIC THEORY. /AUTHOR/

• Corporate Authors:

  University of Washington, Seattle

  Seattle, WA  United States  98195

  Washington State Department of Highways

  Olympia, WA  United States 

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Wyss, A N
  • Mattock, A H
• Publication Date: 0

Subject/Index Terms

• TRT Terms: Bending; Bending moments; Bridge members; Fracture mechanics; Girders; I beams; Length; Longitudinal reinforcement; Prestressed concrete; Ratios; Shear strength; Stiffness; Stirrups; Tension; Torsion; Ultimate strength
• Uncontrolled Terms: Bridge spans
• Old TRIS Terms: Diagonal tension
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00207998
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: Y-1180
• Files: TRIS, USDOT, STATEDOT
• Created Date: Aug 8 1971 12:00AM