PAVEMENT CRACKING: CAUSES AND SOME PREVENTIVE MEASURES

THE PAVEMENT CRACKING PROBLEM WAS INVESTIGATED WITH RESPECT TO DEEP SEATED MOVEMENTS AND ALSO FROM THE STAND- POINT OF 'SHRINKAGE CRACKING' DUE TO THE INHERENT PROPERTIES OF ROAD-BUILDING MATERIALS. IN REGARD TO THE LATTER PART OF THE REPORT, SOME LABORATORY TESTS INVOLVING MIGRATION OF LIME INTO DRIED AND CRACKED SPECIMENS WERE PERFORMED. RESULTS INDICATED THAT THE USE OF THE PROPER PERCENT SOLIDS IN LIME SLURRY, RE-CYCLING OF TREATMENT AND RECONSOLIDATION ALL CONTRIBUTE GREATLY TO THE EFFECTIVENESS OF LIME'S OUTSTANDING ABILITY TO REDUCE VOLUME CHANGE AND INCREASE STRENGTH IN AN UNMIXED CRACKED CLAY. THIS REPORT ESTABLISHES A THEORY THAT THE DEGREE OF SHRINKAGE CRACKING MAY BE A FUNCTION OF CERTAIN STRENGTH CHARACTERISTICS OF BASE AND PAVING MATERIALS. THE DATA FOR TRULY FLEXIBLE BASE MATERIALS SHOW THE COMPRESSIVE STRENGTHS OF SUCH MATERIALS TO BE MANY TIMES GREATER THAN ARE THEIR RESPECTIVE TENSILE STRENGTHS. A SHEAR DIAGRAM CLASSIFICATION CHART DIVIDES ALL SOIL MATERIALS, WITH OR WITHOUT STABILIZATION, INTO THREE GROUPS, TWO OF WHICH ARE SUSCEPTIBLE TO SHRINKAGE CRACKING AND ONE WHICH IS NOT. A CHART SHOWS THE RELATION OF COMPRESSIVE STRENGTH TO THE RATIO OF COMPRESSIVE TO TENSILE STRENGTH FOR MATERIALS WITH WIDELY VARYING CHARACTERISTICS. A LINE IS DRAWN WHICH APPEARS TO SEPARATE MATERIALS BELIEVED TO BE HIGHLY SUSCEPTIBLE TO SHRINKAGE CRACKING FROM THOSE WHICH ARE LESS SUSCEPTIBLE. RECOMMENDATIONS ARE MADE FOR THE USE OF WATER AND LIME TO PREVENT DEEP SEATED SWELLING, ADEQUATE THICKNESS OF BASE TO SUPPORT LOADS, WIDE SHOULDERS TO PREVENT CRACKING OF CLAY SUB-GRADES AND STABILIZED MATERIALS WHICH HAVE RELATIVELY HIGH RATIOS OF COMPRESSIVE TO TENSILE STRENGTHS. THE USE OF HIGH-GRADE FLEXIBLE BASE MATERIALS CONTAINING LOW AMOUNTS OF FINE SILT IS RECOMMENDED FOR USE IN CONSTRUCTION OF FLEXIBLE PAVEMENTS IN AREAS SUSCEPTIBLE TO FROST DAMAGE. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 154-162
  • Monograph Title: Control of pavement slipperiness: asphalt pavement cracking
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00207027
  • Record Type: Publication
  • Report/Paper Numbers: HS-005 947, HS-009 490
  • Files: TRIS, TRB, ATRI
  • Created Date: Jul 28 1994 12:00AM