DESIGN OF ANCHORAGE-ZONE REINFORCEMENT IN PRESTRESSED CONCRETE BEAMS

THE REPORT PRESENTS A SIMPLE METHOD FOR THE DESIGN OF TRANSVERSE REINFORCEMENT NEAR THE END ZONES OF PRESTRESSED CONCRETE BEAMS TO RESTRAIN ANCHORAGE ZONE CRACKS. THE METHOD IS CONFIRMED BY TEST RESULTS. THE DESIGN METHOD IS BASED ON THE ASSUMPTION THAT LONGITUDINAL CRACKS WILL FORM IN THE END ZONE. THE ANALYSIS OF THE EQUILIBRIUM OF THE CRACKED END ZONE YIELDED EXPRESSIONS FOR THE LOCATION OF THE CRACK AND THE MAGNITUDE OF THE UNBALANCED MOMENT WHICH CREATES THE TENSION FORCES IN THE TRANSVERSE STEEL. A SIMPLE PROCEDURE RESULTED FOR THE DESIGN OF STIRRUPS TO RESTRAIN THE CRACKS. ONE SERIES OF TESTS CONFIRMED THE PROPOSED METHOD AND PREDICTED THE LOCATION OF THE CRACK AND THE FORCES IN THE REINFORCEMENT. A SECOND SERIES OF TESTS RESULTED IN A FORCE-SLIP RELATIONSHIP THAT WAS USED TO DEVELOP AN EXPRESSION TO LIMIT THE WIDTH OF THE CRACK. THE INVESTIGATION BROUGHT OUT THE IMPORTANCE OF THE SPALLING STRESSES, TRANSVERSE TENSILE STRESSES AWAY FROM THE LINE OF THE LOAD, AND SHOWED THAT FOR ECCENTRIC PRESTRESSING FORCES THESE STRESSES ARE LARGER FOR RECTANGULAR THAN FOR I-SHAPED END BLOCKS. /BPR/

• Supplemental Notes:
  • Hpr, Ihr-10
• Corporate Authors:

  University of Illinois, Urbana-Champaign

  Urbana, IL  United States  61801

  Illinois Department of Transportation

  Division of Highways, 2300 South Dirksen Parkway
  Springfield, IL  United States  62764
• Authors:
  • Gergely, P
  • Sozen, M A
• Publication Date: 1966-5

Subject/Index Terms

• TRT Terms: Anchorages; Beams; Design; Fracture mechanics; Material reinforcement; Methodology; Prestressed concrete; Prestressing; Prevention; Spalling; Stirrups; Stresses; Tension
• Uncontrolled Terms: Tensile stress
• Old TRIS Terms: End-zone
• Subject Areas: Bridges and other structures; Design; Highways; Security and Emergencies;

Filing Info

• Accession Number: 00207803
• Record Type: Publication
• Source Agency: Bureau of Public Roads /US
• Files: TRIS
• Created Date: Oct 1 1994 12:00AM