ASPHALT MIXTURE BEHAVIOR IN REPEATED FLEXURE: A STUDY OF AN IN-SERVICE PAVEMENT NEAR MORRO BAY, CALIFORNIA

A CONTINUING STUDY IS IN PROGRESS ON THE FATIGUE RESPONSE OF ASPHALT PAVING MIXTURES WHICH INCLUDES NOT ONLY INVESTIGATION OF THE FACTORS AFFECTING THE BEHAVIOR OF ASPHALT MIXTURES IN REPEATED FLEXURE, BUT ALSO CONSIDERATION OF THE FATIGUE FACTOR IN THE DESIGN OF ASPHALT CONCRETE PAVEMENTS. INVESTIGATIONS HAVE INCLUDED: (1) LABORATORY FATIGUE TESTS, BOTH ON SPECIMENS SAWED FROM THE ASPHALT CONCRETE COURSE AND ON LABORATORY PREPARED SPECIMENS WITH THE SAME COMPONENTS, (2) TRIAXIAL COMPRESSION REPEATED LOAD TESTS ON THE OTHER COMPONENTS OF THE PAVEMENT SECTION AS WELL AS ON THE SUBGRADE MATERIAL, AND (3) PREDICTION OF THE POTENTIAL FOR FATIGUE DISTRESS IN THIS PAVEMENT SECTION USING THE LABORATORY TEST RESULTS TOGETHER WITH MULTI-LAYER ELASTIC THEORY. A BRIEF SUMMARY IS PRESENTED OF OTHER INVESTIGATIONS NAMELY TO PLACE THE RESULTS OF THIS INVESTIGATION IN BETTER PERSPECTIVE. THE PRIMARY EMPHASIS IN THIS STUDY WAS TO ILLUSTRATE A PROCEDURE WHEREBY THE FATIGUE FACTOR MAY BE INCORPORATED INTO PAVEMENT DESIGN USING AVAILABLE THEORY AND SUITABLE TESTS ON MATERIALS COMPRISING A STRUCTURAL PAVEMENT SECTION. THE USE OF LAYERED ELASTIC THEORY ALONG WITH MATERIAL PROPERTY DETERMINED FROM REPEATED LOAD TESTS ON LABORATORY PREPARED SAMPLES PROVIDES A METHOD FOR THE PREDICTION OF DEFLECTIONS OBTAINED WITH THE TRAVELING DEFLECTOMETER. THIS METHOD ALSO PROVIDES INFORMATION RELATIVE TO THE RESPONSE OF THE MATERIALS IN THE PAVEMENT AS MEASURED IN UNITS OF STRESS AND STRAIN. THE PREDICTION OF SERVICE LIFE OF MORRO BAY PAVEMENT WAS BASED ON A DEFLECTION PREDICTION PROCEDURE RELATED TO AN AVERAGE CONDITION AT THE SITE. A COMPUTER PROGRAM WAS WRITTEN TO FACILITATE COMPUTATIONS FOR FATIGUE LIFE PREDICTION USING MINER'S HYPOTHESIS. THE STEP-BY-STEP PROCEDURE USED IS: (1) THE AXLE LOAD, ITS NUMBER OF APPLICATIONS PER MONTH, AND THE RELATIONSHIP OF TENSILE STRAIN IN THE ASPHALT CONCRETE WITH STIFFNESS FOR THE VARIOUS AXLE LOADS WAS STORED, (2) FOR EACH MONTH THE TENSILE STRAIN INTERPOLATED FOR EACH AXLE LOAD AT THE APPROPRIATE STIFFNESS FOR THE MONTH, (3) USING THE STRAIN LEVEL DETERMINED, THE NUMBER OF LOAD APPLICATIONS TO CAUSE FAILURE IS CALCULATED FROM THE EQUATION OF THE FATIGUE CURVE, (4) THE PROPORTION OF THE FATIGUE LIFE USED BY EACH AXLE LOAD GROUP IS CALCULATED AND THE SUM FOR EACH MONTH DISPLAYED, AND (5) THE SUM OF THE MONTHLY VALUES IS SHOWN AS THE CUMULATIVE DAMAGE PER YEAR. ON THE BASIS OF THE DAMAGE CALCULATED, THE FATIGUE LIFE OF THE PAVEMENT AT MORRO BAY IS APPROXIMATELY 5 1/2 YEARS.

  • Supplemental Notes:
    • Rept No Te 67-4, 70 PP, 29 FIG, 11 TAB, 4 APP
  • Corporate Authors:

    University of California, Berkeley

    Institute of Transportation and Traffic Engineering
    Berkeley, CA  United States 
  • Authors:
    • Monismith, C L
    • Kasianchuk, D A
    • Epps, J A
  • Publication Date: 1967-12

Subject/Index Terms

Filing Info

  • Accession Number: 00211531
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 26 1970 12:00AM