A STUDY OF THE FLEXURAL PROPERTIES OF CERTAIN BLACK BASE MIXTURES

THE DATA PRESENTED IN THIS PAPER REPRESENT AN EXTENSION OF THE ORIGINAL WORK PERFORMED BY JIMENEZ (1) AND LATER AMPLIFIED BY JIMENEZ AND GALLAWAY (2) AND (3) AND MOST RECENTLY BY JIMENEZ (4). FOR EQUIPMENT AND TEST METHODS USED IN MIXING, COMPACTING AND TESTING THE FLEXURE-FATIGUE SPECIMENS AND FOR AN EVALUATION OF THE DEFLECTOMETER AS AN APPROPRIATE TESTING PROCEDURE, THE READER IS REFERRED TO THE REFERENCES CITED ABOVE AND TO LAYMAN (5). IN THIS REGARD, A SERIES OF PAPERS PRESENTED AT THE SECOND INTERNATIONAL CONFERENCE ON THE STRUCTURAL DESIGN OF ASPHALT PAVEMENTS (6) BESPEAK A GROWING APPRECIATION OF THE SYMBIOTIC RELATIONSHIP THAT MAY EXIST BETWEEN THE VISCOELASTIC PROPERTIES OF FLEXIBLE PAVEMENTS ON THE ONE HAND AND THEIR VARIABLE ELASTIC PARAMETERS ON THE OTHER. THE STUDY BY JIMENEZ INVOLVED COARSE SHEET-ASPHALT MIXES COMPACTED INTO SPECIMENS OF FIXED DIAMETER AND MINOR VARIATIONS IN THICKNESS. THREE DIFFERENT PENETRATION GRADES OF ASPHALT CEMENT WERE EMPLOYED AND ALL SPECIMENS WERE TESTED AT THE SAME TEMPERATURE. IN THE STUDY REPORTED IN THIS PAPER A SINGLE PENETRATION GRADE ASPHALT CEMENT WAS EMPLOYED. SPECIMEN DIAMETER REMAINED FIXED, BUT THE THICKNESS AND TEST TEMPERATURE WERE VARIED THROUGH BROADER LIMITS SO AS TO EVALUATE THE INFLUENCE OF BOTH FACTORS ON THE FLEXURAL CHARACTERISTICS OF THE BLACK-BASE MIXTURE DESIGNATED AS "GRADING A." ADDITIONAL SPECIMENS OF VARIABLE THICKNESS WERE CONSTRUCTED USING THE SAME MATERIALS IN A FINER GRADATION, "GRADING B," AND A COARSER GRADATION, "GRADING C." THESE FINER AND COARSER SPECIMENS WERE TESTED AT A SINGLE TEMPERATURE. FOR THE "GRADING A" SPECIMENS A MULTIPLE CORRELATION WAS FOUND TO EXIST BETWEEN THICKNESS AND TEMPERATURE AS INDEPENDENT VARIABLES AND BOTH STIFFNESS AND RESISTANCE TO FLEXURAL FATIGUE AS DEPENDENT VARIABLES. THE RELATIVE DEGREE OF THESE CORRELATIONS BETWEEN THE INDEPENDENT VARIABLES (SINGLY AND IN COMBINATION) AND EACH OF THE TWO DEPENDENT VARIABLES WAS EXPLORED. IT IS THOUGHT THAT THE CORRELATIONS ACHIEVED PROVIDE A METHOD OF EVALUATING THE FLEXURAL PROPERTIES OF PAVING MIXTURES. TEST DATA OBTAINED INDICATE THAT THE FACTOR OF GRADATION AFFECTED TEH FLEXURAL CHARACTERISTICS OF THE BLACK-BASE MIXTURES TESTED TO A LESSER DEGREE THAN THE FACTORS OF THICKNESS AND TEMPERATURE. /AUTHOR/

• Supplemental Notes:
  • Vol 38, pp 684-705, 12 FIG, 12 TAB, 24 REF
• Authors:
  • Layman, A H
  • Phillippi, S W
• Conference:
  • Association of Asphalt Paving Technologists Proc
• Publication Date: 1969-2

Subject/Index Terms

• TRT Terms: Aggregate gradation; Asphalt cement; Bituminous aggregates; Bituminous mixtures; Flexible pavements; Flexural strength; Flexure; Pendulum tests; Sheet asphalt; Temperature; Thickness
• Old TRIS Terms: Gradation
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00211514
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM