FIELD INVESTIGATION OF A PRESTRESSED CONCRETE HIGHWAY BRIDGE LOCATED IN DOUGLAS COUNTY ILLINOIS

CAMBER, STRAIN, CREEP, AND SHRINKAGE MEASUREMENTS WERE MADE OVER A PERIOD OF TWO YEARS ON A THREE-SPAN PRESTRESSED CONCRETE HIGHWAY BRIDGE AND CONCRETE SPECIMENS. THE PRECAST I-SECTION GIRDERS 72 FT. 9 IN. LONG WERE MADE CONTINUOUS FOR LIVE-LOAD FORCES BY REINFORCEMENT CAST IN THE DECK. THE CONSTRUCTION OF THE BRIDGE, AND THE INSTRUMENTATION USED, ARE DESCRIBED. ALTHOUGH THE GREATEST CHANGES IN CAMBER OF THE BEAMS OCCURRED WITHIN THE FIRST 200 DAYS AFTER RELEASE OF PRESTRESS, MEASURABLE MOVEMENTS WERE STILL OCCURRING AFTER MORE THAN TWO YEARS. THE STRAIN MEASUREMENTS EXHIBITED ANNUAL CYCLICAL EXPANSIONS AND CONTRACTIONS, PROBABLY DUE TO CHANGES IN AVERAGE RELATIVE HUMIDITY AT DIFFERENT TIMES OF THE YEAR. MEASURABLE SHORTENING OF THE FIBER OF THE GIRDERS OCCURRED FOR MORE THAN TWO YEARS AFTER RELEASE OF THE PRESTRESSING FORCE, BUT WAS OBSCURED BY THE LARGE CYCLICAL VARIATIONS. THE GREATER LOSS OF PRESTRESS OCCURRED DURING THE FIRST FEW WEEKS AFTER RELEASE, BUT THE LOSSES CONTINUED AT A SLOW RATE THROUGHOUT THE TEST PERIOD. THE CREEP AND SHRINKAGE MEASUREMENTS SHOW THAT THE SHRINKAGE IN THE FIELD WAS MUCH LESS THAN IN THE LABORATORY, BUT THAT THE CREEP VALUES WERE COMPARABLE IN THE TWO ENVIRONMENTS. FURTHER WORK IS REQURIED TO DEFINE THE MAGNITUDE OF CREEP OF CONCRETE SUBJECTED TO VARIABLE ENVIRONMENTAL CONDITIONS, AS MOST ACCEPTED PRESENT CONCEPTS ARE NOT ADEQUATE. /AUTHOR/

  • Corporate Authors:

    University of Illinois, Urbana-Champaign

    Department of Civil and Environmental Engineering
    205 North Mathews Avenue
    Urbana, IL  United States  61801-2352
  • Authors:
    • Houdeshell, D M
    • Anderson, T C
    • Gamble, W L
  • Publication Date: 1972-2

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 138 p.
  • Serial:
    • Issue Number: 375

Subject/Index Terms

Filing Info

  • Accession Number: 00210244
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: R&d Rept
  • Files: TRIS
  • Created Date: Jun 19 1974 12:00AM