PAVEMENT CRACKING, DEFLECTIONS AND ASPHALT HARDENING

THE PROCEDURES AND THE RESULTS OBTAINED WHILE STUDYING THE EFFECTS OF PAVEMENT BENDING AS MEASURED BY BENKELMAN BEAM DEFLECTIONS ARE PRESENTED IN TERMS OF RADIUS OF CURVATURE. A CRITICAL RADIUS OF CURVATURE VALUE OF APPROXIMATELY 300 FEET IS INDICATED. PAVEMENTS SUBJECTED TO REPEATED FLEXING TO THIS RADIUS DEVELOP SEVERE CRACKING. A STUDY OF THE BASIC ASPHALT AND MIXTURE PROPERTIES INDICATES THAT THE BEST CORRELATION IS THE RELATIONSHIP BETWEEN COMPACTION AND PENETRATION OF RECOVERED ASPHALT. RESULTS SHOW THAT HIGH COMPACTION VALUES AID IN RETAINING THE ORIGINAL ASPHALT PROPERTIES. THE STUDY ALSO DEALS WITH THE DEPRECIATION OF PAVEMENT (AS MEASURED BY CHLOE P.S.I.) FOR VARIOUS DEFLECTIONS AND RADIUS OF CURVATURE WITH RESPECT TO AGE AND WITH RESPECT TO 18K EQUIVALENT AXLE LOADS. RESULTS INDICATE THAT BOTH THE BENKELMAN BEAM AND THE CURVATURE METER WILL MEASURE STRAIN ON THIN OR WEAK PAVEMENTS, BUT THE BENKELMAN BEAM IS A BETTER INDICATOR OF STRAINS WHEN THE PAVEMENT IS RELATIVELY THICK OR STRONG. THE STRUCTURAL NUMBER CONCEPT WILL NOT GUARANTEE, IN ITSELF. THAT A STRONG STRUCTURE WILL RESULT, ALTHOUGH A DEFLECTION WILL CONFIRM WHETHER A STRONG OR A WEAK STRUCTURE HAS BEEN BUILT REGARDLESS OF THE STRUCTURAL NUMBER. /FHWA/

Media Info

  • Pagination: 67 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00206484
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: No 71-11p
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: May 21 1973 12:00AM