COEFFICIENT OF FRICTION OF VARIOUS GROOVING PATTERNS ON PCC PAVEMENT

SIX DIFFERENT GROOVING PATTERNS: 1/8 BY 1/8 INCH RECTANGULAR GROOVES SPACED AT 1/2, 3/4 AND ONE INCH CENTERS AND THE NUMBER 6, 7 AND 15 PATTERNS OF THE CHRISTENSEN DIAMOND SERVICES COMPANY WERE CUT IN EACH OF TWO PCC TEST SLABS. ONE SLAB HAD A TROWELLED FINISH WITH AN AVERAGE INITIAL COEFFICIENT OF FRICTION OF 0.14 AS DETERMINED BY THE CALIFORNIA SKID TESTER. THE OTHER SLAB HAD A BURLAP DRAG FINISH WITH AN AVERAGE INITIAL COEFFICIENT OF FRICTION OF 0.35. HIGHER COEFFICIENTS OF FRICTION WERE OBTAINED WITH THE CHRISTENSEN GROOVING PATTERNS THAN BY THE 1/8 BY 1/8 INCH RECTANGULAR GROOVES. THE FRICTIONAL PROPERTIES OF THE BURLAP DRAG FINISH WERE UNCHANGED BY THE 1/8 BY 1/8 INCH RECTANGULAR GROOVES. LONGITUDINAL COEFFICIENT OF FRICTION MEASUREMENTS WERE QUITE ERRATIC FOR THE THREE 1/8 BY 1/8 INCH RECTANGULAR PATTERNS WHICH WERE CUT IN THE TROWELLED PCC SURFACE AND VERY LITTLE IMPROVEMENT IN FRICTIONAL PROPERTIES WERE OBTAINED. FRICTION MEASUREMENTS AT 15 TO 45 DEGREES TO THE DIRECTION OF THE GROOVES WERE MUCH MORE CONSISTENT, AND ARE PROBABLY MORE REPRESENTATIVE OF THE ACTUAL IMPROVEMENT IN THE FRICTIONAL PROPERTIES OF THE SURFACE. THIS IS CAUSED BY THE SMALL CONTACT AREA OF THE TIRE USED ON THE CALIFORNIA SKID TESTER WHICH MAY TOUCH AS FEW AS 2 GROOVES DURING A LONGITUDINAL TEST WITH THE GROOVES SPACED AT ONE INCH. IF 1/8 BY 1/8 INCH RECTANGULAR GROOVES ARE USED, THE GREATEST IMPROVEMENT IN SKID RESISTANCE IS PROVIDED BY THE 1/2 INCH CENTER TO CENTER SPACING. ASSUMING THE CHRISTENSEN PATTERNS DO NOT WEAR EXCESSIVELY, ALL THREE OF THE PATTERNS TESTED APPEAR TO BE SUPERIOR TO THE 1/8 BY 1/8 INCH GROOVING PATTERNS IN TERMS OF THE MEASURED COEFFICIENT OF FRICTION. HOWEVER, THE USE OF RECTANGULAR LONGITUDINAL GROOVES AT A NUMBER OF FIELD LOCATIONS HAS RESULTED IN A MARKED REDUCTION IN WET WEATHER ACCIDENTS. FURTHER STUDIES ARE REQUIRED PRIOR TO RECOMMENDING ANY SPECIFIC PATTERN. /AUTHOR/

  • Supplemental Notes:
    • Hpr-pr-1 (6), B-3-1
  • Corporate Authors:

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Zube, E
    • Skog, J B
    • Munday, H A
  • Publication Date: 1968-6

Subject/Index Terms

Filing Info

  • Accession Number: 00206348
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: Mar 18 1994 12:00AM