UNIFORMITY OF CORES AN INDICATION OF PAVEMENT QUALITY

IN THIS INVESTIGATION CORES FROM PAVEMENT SHOWING VARYING DEGREES OF SCALING WERE STUDIED. THE CORES WERE SAWED IN HALF LENGTHWISE AND THE DISTRIBUTION OF THE MORTAR AND AGGREGATE WAS OBSERVED. ONE OF THE HALVES WAS SAWED ACROSS TO GIVE A TOP AND A BOTTOM SECTION. THE ABSORPTION, SPECIFIC GRAVITIES AND RESISTANCE TO FREEZING AND THAWING IN A 10 PER CENT CALCIUM CHLORIDE SOLUTION OF THESE CORE SECTIONS WERE DETERMINED. IN THE CASE OF CORES FROM PAVEMENTS OF GOOD SERVICE RECORD THERE WAS A HIGH DEGREE OF UNIFORMITY IN THE PROPERTIES STUDIED BETWEEN THE DIFFERENT CORES FROM THE SAME PAVEMENT AND BETWEEN THE TOP AND BOTTOM SECTIONS OF THE SAME CORES. IN THE CASE OF CORES FROM PAVEMENTS OF POOR SERVICE RECORD THERE WAS A WIDE VARIATION IN THESE SAME PROPERTIES BOTH BETWEEN CORES AND THE SECTIONS OF THE SAME CORE. THE STUDY HAS DEVELOPED 3 SIGNIFICANT OBSERVATIONS: (1) THE QUALITY OF THE CONCRETE USED IN PAVEMENTS AS MEASURED BY THE ABSORPTIONS AND RESISTANCE TO FREEZING AND THAWING IN A 10 PER CENT CALCIUM CHLORIDE SOLUTION VARIES WIDELY. THE CORE SECTIONS FROM CERTAIN PAVEMENTS LOST 50 PER CENT OF THEIR WEIGHT IN 5 TO 10 CYCLES OF FREEZING AND THAWING, WHEREAS OTHERS HAVE NOT LOST THIS AMOUNT IN 160 CYCLES. (2) THE RESISTANCE TO FREEZING AND THAWING WAS CLOSELY RELATED TO THE ABSORPTION OF THE CONCRETE. THE HIGHER THE ABSORPTION THE LOWER THE RESISTANCE TO FREEZING AND THAWING. (3) SERIOUS SCALING RESULTS WHEN THE CONCRETE HAS A HIGH ABSORPTION AND IS BADLY SEGREGATED DURING PLACING SO AS TO FORM A THICK LAYER OF MORTAR ON THE SURFACE. SLIGHT SURFACE SCALING RESULTS WHEN A THIN LAYER OF MORTAR IS FORMED ON THE SURFACE OF CONCRETES HAVING LOW ABSORPTION. IT IS CONCLUDED FROM THIS STUDY THAT SIGNIFICANT IMPROVEMENTS IN THE LIFE OF CONCRETE PAVEMENTS EXPOSED TO FROST ACTION COULD BE MADE BY USING LOW SLUMP CONCRETE AND BY RIGID CONTROL OF THE PLACING OPERATIONS TO THE END THAT SEGREGATION OF THE MIX AND NON- UNIFORMITY OF THE SLAB ARE AVOIDED. /AUTHOR/

  • Supplemental Notes:
    • Vol 20, pp 568-586, 5 FIG, 5 TAB
  • Authors:
    • HANSEN, W C
    • Gage, R B
  • Discussers:
    • PAUL, I
  • Publication Date: 1941

Media Info

  • Monograph Title: Proceedings of the Twentieth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 3-6, 1940
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00207272
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 23 1971 12:00AM