DURABILITY AND BEHAVIOR OF PRESTRESSED CONCRETE BEAMS

THIS REPORT IS THE THIRD IN A SERIES DESCRIBING A STUDY WHICH HAS BEEN CONDUCTED TO DEVELOP INFORMATION ON THE DURABILITY OF PRESTRESSED CONCRETE BEAMS. THE WORK DESCRIBED INVOLVED LABORATORY TESTS AND RESULTS OF FOUR PRESTRESSED CONCRETE BEAMS WHICH HAS BEEN EXPOSED TO TIDAL WEATHER CONDITIONS FOR A CONSIDERABLE PERIOD OF TIME. TWO BEAMS WERE EXPOSED IN AN UNLOADED CONDITION FOR 10 YEARS IN MAINE--TWO IN A FLEXURALLY LOADED CONDITION AT ST. AUGUSTINE TO INDUCE CRACKING. THE LAB TESTS CONDUCTED CONSISTED OF EXAMINATION AND TENSILE TESTING OF THE STEEL PRESTRESSING STRANDS AFTER REMOVAL FROM THE BEAMS AND TESTS FOR DEPTH OF CARBONATION AND CHLORIDE PENETRATION. SIGNIFICANT FINDINGS INCLUDE: (1) INTERNAL CORROSION IS GREATER THAN EXTERNAL PROGRESSING ALONG THE CENTER WIRE OF EACH STRAND; (2) EPOXY PADS USED FOR PROTECTION AGAINST CORROSION WERE NOT EFFECTIVE IN PROTECTING THE ENDS OF THE STRANDS; (3) CARBONATION WAS NOT A FACTOR IN THE CORROSION OF THE STEEL STRANDS; (4) PENETRATION TESTS REVEALED THAT SUFFICIENT CHLORIDES WERE PRESENT IN THE TEST BEAMS TO CAUSE CORROSION ON THE PRESTRESSING STRANDS; (5) THE FLEXURALLY LOADED STEEL STRANDS WERE IN POORER CONDITION THAN THOSE UNLOADED; (6) THE MAJOR CAUSE OF CORROSION IN THE UNLOADED CONDITION SEEMED TO BE DUE TO INADEQUATE PROTECTION OF THE EPOXY PADS AND SUBSEQUENT SPALLING--IN THE FLEXURALLY LOADED CONDITION, THE CRACKING IN THE BEAMS RESULTING FROM THE INITIAL LOADING.

  • Supplemental Notes:
    • TR 6-570
  • Corporate Authors:

    U.S. Army Waterways Experiment Station

    3909 Halls Ferry Road
    Vicksburg, MS  United States  39180-6199
  • Authors:
    • Roshore, E C
  • Publication Date: 1971-10

Media Info

  • Features: Photos;
  • Pagination: 41 p.
  • Serial:
    • Issue Number: 3

Subject/Index Terms

Filing Info

  • Accession Number: 00209686
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 28 1972 12:00AM