A SIMPLE GUIDE FOR THE DESIGN OF FLEXIBLE PAVEMENTS USING CRUSHED STONE

FLEXIBLE PAVEMENT DESIGN MUST CONSIDER THE FOLLOWING THREE ELEMENTS: (1) THE FOUNDATION, EITHER A FIRM, UNYIELDING SUBBASE OR A STABILIZED OR OTHERWISE IMPROVED SUBGRADE, (2) THE BASE WHOSE FUNCTION IS TO TRANSMIT AND CUSHION WHEEL LOAD STRESSES TO AN EXTENT THAT THE FOUNDATION AND SUBGRADE ARE NOT OVERSTRESSED, AND (3) THE BITUMINOUS MAT, A COMBINATION OF LAYERS OF AGGREGATES AND BITUMINOUS BINDERS WHOSE FUNCTION IS TO RESIST ABRASION, TANGENTIAL STRESSES FROM ACCELERATION AND DECELERATION, AND THE INFILTRATION OF MOISTURE. EMPHASIS IN THE DISCUSSION IS LAID ON THE ADVANTAGES AND THE PROPER USE OF DENSE GRADED CRUSHED STONE FOR THE FOUNDATION AND BASE COURSES. IT IS EMPHASIZED THAT THE GRADING SHOULD BE UNIFORM AND CONTINUOUS FROM THE MAXIMUM SIZE DOWN TO AND INCLUDING THE DUST OF FRACTURE. THE MAXIMUM SIZE OF AGGREGATE SHOULD BE THE LARGEST THAT CAN BE HANDLED WITHOUT SEGREGATION. THE PLASTICITY INDEX SHOULD BE KEPT AS LOW AS POSSIBLE. NON-PLASTIC FINES ARE SHOWN TO BE THE BEST. THE AGGREGATE SHOULD BE COMPACTED TO THE MAXIMUM DENSITY OBTAINABLE AND SHOULD CONSIST OF CRUSHED STONE THROUGHOUT THE SIZE RANGE TO ASSURE THE HIGHEST STRENGTH AND GREATEST RIGIDITY. THE IMPORTANCE OF ACHIEVING THE MAXIMUM DENSITY PRACTICABLE FOR THE GRADING SELECTED FOR THE JOB IS EMPHASIZED. THE CHOICE OF THE TYPE AND THICKNESS OF THE BITUMINOUS MAT DEPENDS UPON A NUMBER OF FACTORS. FOR RURAL HIGHWAYS AND LOCATIONS WHERE TRAFFIC VOLUMES ARE APT TO BE LIGHT, ADVANTAGE MAY BE GAINED THROUGH THE USE OF STAGE CONSTRUCTION, BY WHICH A TEMPORARY OR SEMI-PERMANENT WEARING SURFACE IS APPLIED AS PART OF INITIAL CONSTRUCTION, AND A FINAL SURFACING IS PROGRAMMED FOR LATER APPLICATION. A BITUMINOUS CONCRETE MAT IS NEEDED WHEN HEAVIER TRAFFIC IS EXPECTED AND WHERE SUPERIOR RIDING QUALITY IS DEEMED ESSENTIAL. ON A BASE AND FOUNDATION CONSTRUCTED FOR HEAVY TRAFFIC, A THICKNESS OF BITUMINOUS CONCRETE OF FROM 4 TO 6 INCHES IS HIGHLY RECOMMENDED. THICKNESS DESIGN OF THE BASE AND BITUMINOUS MAT IS DISCUSSED.

  • Supplemental Notes:
    • pp 1-16, 6 FIG, 1 TAB, 1 APP
  • Corporate Authors:

    NATIONAL CRUSHED STONE ASSOCIATION

    WASHINGTON, DC  United States 
  • Authors:
    • Nichols, F P
  • Publication Date: 1968-3

Subject/Index Terms

Filing Info

  • Accession Number: 00205573
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 1 1994 12:00AM