STATEWIDE INVESTIGATION OF FLEXIBLE PAVEMENTS--FIRST INTERIM REPORT

THE STUDY WAS INITIATED IN 1955 TO DEVELOP INFORMATION ON THE DEFLECTION BEHAVIOR OF SEVERAL SELECTED FLEXIBLE PAVEMENTS OF DIFFERENT DESIGN, BY MEANS OF THE NEWLY DEVELOPED BENKELMAN BEAM TEST. IN 1960 THE STUDY WAS EXPANDED TO INCLUDE ALL NEWLY CONSTRUCTED FLEXIBLE PAVEMENTS. ROUTINE OBSERVATIONS INCLUDED BENKELMAN BEAM DEFLECTION MEASUREMENTS FOR A 11.2-KIP WHEEL LOAD IN BOTH WHEEL PATHS OF ONE LANE. DATA ON PAVEMENT STRUCTURE DESIGN, CONSTRUCTION, TRAFFIC AND ENVIRONMENTAL CONDITIONS WERE COMPILED. INFORMATION ON THE ROADBED MATERIAL WAS COMPILED FROM PHYSIOGRAPHIC AND OTHER SOIL MAPS AND FROM CONSTRUCTION RECORDS. A MORE INTENSIVE STUDY WAS MADE OF ONE OF THE ORIGINALLY SELECTED PAVEMENTS /U.S. 40 WEST/ THAT HAS PERFORMED EXCEPTIONALLY WELL. SEVEN TEST SITES WERE INCLUDED. THESE SITES WERE SELECTED TO REPRESENT THE RANGE IN DEFLECTION AND PERFORMANCE ENCOUNTED THROUGHOUT THE 16-MILE LENGTH OF THE TEST SECTION. ONE OR TWO 12-INCH DIAMETER CORES WERE DRILLED AND SAMPLES OF EACH PAVEMENT COMPONENT AND THE ROADBED SOIL WERE OBTAINED AT EACH SITS. FLEXURE AND SONIC MODULUS TESTS OF BEAMS, AND PERMEABILITY TESTS OF CUBES SAWED FROM THE CORES WERE CONDUCTED. THE VOID CONTENT OF THE MIX AND THE PENETRATION OF EXTRACTED ASPHALT CEMENT WERE DETERMINED. HVEEM STABILOMETER TESTS WERE MADE ON SOIL SAMPLES. THE PRINCIPAL FINDINGS OF THE STUDY TO DATE ARE AS FOLLOWS' 1. FOR A GIVEN WHEEL LOAD' DEFLECTIONS OF A PAVEMENT OF CONSTANT DESIGN ARE DEPENDENT ON THE ROADBED SOIL TYPE, FOR EACH PAVEMENT, OUTER WHEEL PATH DEFLECTIONS ARE GENERALLY LARGER AND MORE DISPERSED THAN THOSE OF THE INNER WHEEL PATH, AND SPRINGTIME DEFLECTIONS OF A GIVEN PAVEMENT AND WHEEL PATH ARE LARGER AND MORE DISPERSED THAT FALL DEFLECTIONS, 2. DISTRESS IN A PAVEMENT IS NOT SIGNALED BY A CHANGE IN MAGNITUDE OF DEFLECTION. 3. THE EXCELLENT PERFORMANCE OF THE U. S. 40 WEST PAVEMENT IS THE RESULT OF AN ADEQUATE STRUCTURAL SECTION, PROTECTION OF THE ROADBED SOIL BY AN IMPERVIOUS, LOW VOID CONTENT SURFACE COURSE, CONTINUED VIABILITY OF THE ASPHALT CONCRETE AND GOOD DRAINAGE. /BPR/

  • Supplemental Notes:
    • Hpr-1/1/, BPR9, STATE58-46
  • Corporate Authors:

    Maryland State Roads Commission

    ,    
  • Authors:
    • Mullen, W G
    • Clingan, W R
    • Paulis, E T
  • Publication Date: 1965-7

Subject/Index Terms

Filing Info

  • Accession Number: 00206263
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: Dec 1 1994 12:00AM