PRESTRESSING DUCT CURVATURE FORCES

WHEN PRESTRESSING DUCTS WERE BUNDLED AND BENT THROUGH SHARP CURVATURE, CRUSHING OF DUCTS ACCOMPANIED WITH CONCRETE SPALLING OCCURED. TO PREVENT THIS, THE STATE SET A MINIMUM EQUIVALENT CIRCULAR CURVE RADIUS OF 60 FT. AND PLACED IN THEIR PLANS REQUIRED DUCT ARRANGEMENTS AND MINIMUM CONCRETE COVER. THIS TRIAL BEAM USED THE MOST CRITICAL ARRANGEMENT SET ON A 50 FT. RADIUS CURVE AND A COMPRESSION FORCE GREATER THAN ALLOWED BY AASHO. NO CRUSHING OF THE DUCTS WAS OBSERVED BUT SOME CRACKING DID OCCUR. THIS CRACKING IS BELIEVED TO BE A POISSON'S EFFECT AND IS NOT CONSIDERED DETRIMENTAL TO THE LOAD CARRYING CAPACITY OF THE STRUCTURE. AT ALLOWABLE LEADS AND CURVATURE CRACKING SHOULD BE MINIMAL. /FHWA/

  • Corporate Authors:

    California Division of Highways

    Bridge Department
    Sacramento, CA  United States  05914

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • STEWART, C F
    • Klein, E D
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00212101
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: D-4-92
  • Files: TRIS, USDOT
  • Created Date: Aug 8 1971 12:00AM