A STUDY OF MISALIGNED DOWELS IN CONCRETE PAVEMENTS

A LABORATORY INVESTIGATION WAS MADE TO MEASURE THE EFFECTS OF MISALIGNED DOWELS (LOAD TRANSFER DEVICES) ON THE FORCE NECESSARY TO SEPARATE TWO CONNECTED SLABS. THIRTY-EIGHT SPECIMENS, 3-FEET WIDE, 5 1/2-FEET LONG, AND 10-INCHES THICK WERE CAST AND TESTED AT 2 AND 7 DAYS AGE. THREE 1 1/4 IN 0 X 16 IN. DOWEL BARS WERE PLACED AT THE MIDDEPTH OF A CONSTRUCTION JOINT FORMED AT THE MIDLENGTH OF THE SPECIMEN. THE DOWELS WERE PLACED ON 1-FOOT CENTERS AND THE 2 OUTER DOWELS WERE ALIGNED PERPENDICULAR TO THE JOINT FACE. THE CENTER DOWEL WAS MISALIGNED UP TO 3 INCHES HORIZONTALLY AND UP TO 1 INCH BOTH VERTICALLY AND OBLIQUELY.THE ANALYSIS PRIMARILY COMPARES THE FORCES NECESSARY TO OPEN THE JOINTS SPECIFIC DISTANCES (1/2 AND 3/4 INCHES), ALTHOUGH THE MOVEMENTS IN THE OTHER TWO DIRECTIONS ARE ALSO PRESENTED. THE MEASURED FORCES ARE ADJUSTED FOR DIFFERENT CONCRETE STRENGTHS AND ARE PLOTTED AGAINST THE MAGNITUDE OF THE MISALIGNMENT. IT WAS FOUND THAT (1) THE FORCE REQUIRED TO PRODUCE A SPECIFIC OPENING VARIED AS A FUNCTION OF THE MISALIGNMENT, (2) VERTICAL MISALIGNMENTS ARE THE MOST CRITICAL AND HORIZONTAL THE LEAST SEVERE, (3)1/4 INCH VERTICALLY OR 3/4 INCH HORIZONTALLY APPEAR TO BE TOLERABLE FOR A 1/2 INCH OPENING, (4) A 1 INCH VERTICAL MISALIGNMENT CAUSES SIGNIFICANT SURFACE SPALLING AT EARLY CONCRETE AGES, (5) MISALIGNMENTS CAUSE CONCRETE CRUSHING ON THE BEARING SURFACES, AND (6) THE DOWEL LUBRICANT APPEARS TO BE A SIGNIFICANT VARIABLE IN DOWEL ACTION. THE RESULTS COULD BE USED TO PROVIDE MEANINGFUL VALUES FOR TOLERATE DOWEL MISALIGNMENTS IN CONSTRUCTION SPECIFICATIONS. /AUTHOR/

  • Supplemental Notes:
    • Hpr-1/2/, 930-037, BPR:9
  • Corporate Authors:

    University of Alabama, University

    P.O. Box 1968
    University, AL  USA  35486

    Alabama State Highway Department

    11 South Union Street
    Montgomery, AL  USA  36130
  • Authors:
    • Segner, E P
    • Cobb, J R
  • Publication Date: 1967-8

Subject/Index Terms

Filing Info

  • Accession Number: 00205350
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Dec 15 1994 12:00AM