INFLUENCE OF MIXTURE VARIABLES ON THE FLEXURAL FATIGUE PROPERTIES OF ASPHALT CONCRETE

STUDY WAS CONDUCTED TO OBTAIN MORE DEFINITIVE INFORMATION ON THE FATIGUE BEHAVIOR OF ASPHALT PAVING MIXTURES. CONTROLLED-STRESS FLEXURAL FATIGUE TESTS WERE MADE ON ASPHALT CONCRETE MIXTURES. DATA ARE PRESENTED TO ILLUSTRATE THE INFLUENCE OF: MIXTURE STIFFNESS, AIR VOID CONTENT, AGGREGATE GRADATION, AGGREGATE TYPE, ASPHALT CONTENT, AND ASPHALT TYPE. A SUMMARY IS PRESENTED OF THE NUMBER OF VARIABLES INFLUENCING FATIGUE RESPONSE. THE FOLLOWING FINDINGS APPEAR WARRANTED: (1) BOTH FATIGUE LIFE AND MIXTURE STIFFNESS ARE REDUCED BY AN INCREASE IN AIR VOID CONTENT, (2) SINCE THE AIR VOID CONTENT VERSUS FATIGUE LIFE RELATIONSHIPS ARE NOT IDENTICAL AT THE SAME STRESS LEVEL FOR THE MIXES INVESTIGATED, IT IS POSSIBLE THAT THE STRUCTURE OF THE VOIDS AS WELL AS THE ABSOLUTE VALUE OF THE VOID CONTENT OF MIXES HAS AN IMPORTANT INFLUENCE ON FATIGUE LIFE, (3) RESULTS OF TESTS CONDUCTED AS WELL AS TESTS PERFORMED BY OTHER INVESTIGATORS SUGGEST THAT AGGREGATE GRADING HAS LITTLE EFFECT ON THE LOCATION OF THE STRAIN VS. FATIGUE LIFE RELATIONSHIP THAT CANNOT BE EXPLAINED BY DIFFERENCES IN ASPHALT OR AIR VOID CONTENT, (4) THE EFFECT OF AGGREGATE TYPE ON FATIGUE BEHAVIOR IS NOT CLEAR, (5) ASPHALT TYPE WAS SHOWN TO INFLUENCE BOTH THE LOCATION AND SLOPE OF REGRESSION LINES RELATING BOTH STRESS AND STRAIN AND FATIGUE LIFE, (6) DATA OBTAINED FROM THIS INVESTIGATION AS WELL AS FROM ELSEWHERE INDICATE AN OPTIMUM ASPHALT CONTENT FOR BEST FATIGUE RESPONSE, (7) A METHOD WAS DEVELOPED TO PERMIT THE ENGINEER TO DETERMINE A MIXTURE STRAIN VS. FATIGUE LIFE RELATIONSHIP BY PERFORMING A LIMITED NUMBER OF FATIGUE TESTS OVER A RANGE IN ASPHALT CONTENTS SO THAT AN OPTIMUM ASPHALT CONTENT MAY BE SELECTED, AND (8) A RELATIONSHIP IS PRESENTED OF THE FATIGUE RESPONSE OF MIXES CONTAINING DENSE-GRADED AGGREGATE REPRESENTATIVE OF CALIFORNIA REQUIREMENTS WITH CERTAIN STIFFNESSES.

• Supplemental Notes:
  • Vol 38, pp 423-464, 23 RIG, 11 TAB, 14 REF, 1 APP
• Authors:
  • Epps, J A
  • Monismith, C L
  • Warden, W B
  • Pell, P S
  • Kallas, B F
  • Terrell, R L
  • Busching, H W
  • Mcleod, N W
• Discussers:
  • Marker
• Conference:
  • Association of Asphalt Paving Technologists Proc
• Publication Date: 1969-2

Subject/Index Terms

• TRT Terms: Aggregate gradation; Air voids; Asphalt; Asphalt concrete; Asphalt content; Bituminous mixtures; Fatigue (Mechanics); Fatigue (Physiological condition); Fatigue tests; Stiffness
• Uncontrolled Terms: Fatigue life
• Old TRIS Terms: Air voids content
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 00207106
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM