MAINTENANCE OF JOINTS IN CONCRETE PAVEMENTS AS RELATED TO THE PUMPING ACTION OF THE SLABS

APPROXIMATELY 300 MILES OF CONCRETE PAVEMENTS IN NORTH CAROLINA WERE SURVEYED TO DETERMINE THE EXTENT AND NATURE OF PUMPING AND ITS RELATION TO TRAFFIC PAVEMENT DESIGN FEATURES AND SUBGRADE SOILS. THE MOST SEVERE PUMPING OCCURRED AT TRANSVERSE CRACKS. VERY LITTLE DIFFERENCE WAS FOUND EITHER IN THE AMOUNT OR SEVERITY OF PUMPING AT EXPANSION JOINTS COMPARED TO PUMPING AT CONTRACTION JOINTS. THE OLDER PAVEMENTS, BUILT WITHOUT EXPANSION JOINTS ON SUBGRADE SOILS CONDUCIVE TO PUMPING, SHOWED LESS PUMPING THAN DID THE NEWER PAVEMENTS BUILT ON SIMILAR SOILS AND HAVING EXPANSION JOINTS AT 90 OR 120 FT. INTERVALS AND INTERMEDIATE CONTRACTION JOINTS AT 30 FT. INTERVALS. BOTH TYPES OF JOINTS WERE EQUIPPED WITH LOAD TRANSFER DEVICES. CONSIDERABLY MORE PUMPING OCCURRED ON PAVEMENT WIDENING BUILT WITH EXPANSION JOINTS THAN ON THE ORIGINAL PAVEMENTS WHICH WERE BUILT WITHOUT EXPANSION JOINTS. ALL SOILS SAMPLED FROM UNDER PUMPING SLABS WERE OF A PLASTIC NATURE AND CONTAINED LESS THAN 50 PER CENT SAND AND GRAVEL (RETAINED ON THE NO. 270 SIEVE) IN THE TOTAL SOIL. NO PUMPING WAS FOUND ON SOILS HAVING MORE THAN 50 PER CENT SAND AND GRAVEL IN THE TOTAL SOIL. A RECONNAISSANCE SURVEY WAS MADE ON 237.6 MILES OF CONCRETE PAVEMENT IN KANSAS TO ASSESS THE DEGREE AND EXTENT OF PUMPING ON THE PRINCIPAL TRAFFIC ROUTES DURING THE SPRING WET WEATHER SEASON. SAMPLES OF THE SUBGRADE FROM 54 SECTIONS WERE TAKEN AT TWO LOCATIONS TO DETERMINE WATER CONTENT, DENSITY, AND MOISTURE-DENSITY RELATIONS IN THE COMPACTION TEST. LOAD DEFLECTION TESTS WERE MADE AT THE SAME TRANSVERSE JOINTS WHERE SOIL SAMPLES HAD BEEN TAKEN. TRAFFIC DATA, CONSTRUCTION RECORDS, AND DATA ON PAVEMENT DESIGN FEATURES WERE ASSEMBLED FOR EACH PROJECT AND CORRELATED WITH PUMPING. NO SIGNIFICANT DIFFERENCE WAS FOUND IN THE AMOUNT OF PUMPING ON COMPARABLE PAVEMENTS WITH OR WITHOUT LIP CURB. THE MOST SIGNIFICANT SINGLE RELATIONSHIP BETWEEN ANY FEATURE OR COMBINATION OF FEATURES OF PAVEMENT DESIGN, SUBGRADE SOIL TYPE, TRAFFIC OR OTHER FACTOR WHICH MAY AFFECT PUMPING LIES IN THE TEXTURAL CLASSIFICATION OF THE SUBGRADE SOIL TYPE, TRAFFIC OR OTHER FACTOR WHICH MAY AFFECT PUMPING LIES IN THE TEXTURAL CLASSIFICATION OF THE SUBGRADE SOIL IMMEDIATELY BENEATH THE PAVEMENT. NO INSTANCE OF PUMPING WAS FOUND TO OCCUR ON SUBGRADE SOILS HAVING ONE OR MORE OF THE FOLLOWING TEXTURAL CHARACTERISTICS: 1. LESS THAN 15 PERCENT CLAY, 2. MORE THAN 50 PERCENT SAND AND GRAVEL (LARGER THAN 0.05 MM), OR 3. MORE THAN 40 PERCENT RETAINED ON THE NO. 200 SIEVE. /AUTHOR/

  • Supplemental Notes:
    • Res Rept 1-D, 67 PP, 13 FIG, 18 TAB
  • Authors:
    • Allen, H
  • Publication Date: 1946

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  • Accession Number: 00218897
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 29 1972 12:00AM