FINAL SUMMARY REPORT-FATIGUE OF CONCRETE

A SUMMARY IS PRESENTED OF FUNDAMENTAL RESEARCH CONDUCTED ON FATIGUE OF CONCRETE. FATIGUE TESTS WERE MADE ON MORTAR BEAMS CONTAINING VARIOUS TYPES OF PRE-SHAPED INCLUSIONS. THESE BEAMS WERE ASSUMED TO BE SIMPLIFIED MODELS OF CONCRETE AND WERE USED TO STUDY AGGREGATE-MORTAR BOND, DRYING SHRINKAGE, AND INFLUENCE OF AGGREGATES' ELASTIC MODULUS. FATIGUE STUDIES INVESTIGATED THE FRACTURE MECHANICS APPROACH TO FATIGUE FAILURE. BEAMS WERE TESTED STATICALLY TO DETERMINE RELATIONSHIPS BETWEEN FLEXIBILITY AND FLOW DEPTH. THE REMAINING PHASES DEALT WITH RESTRAINED SHRINKAGE, STRESS RATE, AND RELATION BETWEEN MODULUS OF RUPTURE AND THE DYNAMIC PROPERTIES OF CONCRETE. TEST RESULTS SHOWED THAT INCLUSIONS PLACED IN TENSILE REGION REDUCED STATIC STRENGTH 13 TO 47 PERCENT AND SEVERELY RESTRICTED THE PLANE OF FAILURE. HOWEVER, WHEN FATIGUE BEHAVIOR WAS EXPRESSED IN TERMS OF STATIC STRENGTH, NO STATISTICALLY SIGNIFICANT DIFFERENCE EXISTED BETWEEN BEAMS WITH AND WITHOUT INCLUSIONS, NOR WERE ANY NOTICEABLE EFFECTS ATTRIBUTED TO SHRINKAGE STRESSES IN MORTARS OF VARIATIONS IN ELASTIC MODULUS OF INCLUSIONS. STATIC TESTS INDICATE THAT FATIGUE DAMAGE EXISTS ON MICROSCOPIC LEVEL AS SLOW AND STABLE PROPAGATION OF ONE OR MORE CRACKS. BOND BETWEEN COARSE AGGREGATE AND MORTAR MATRIX AFFECTS THE RESPONSE OF CONCRETE TO STATIC AND REPEATED LOADING.

  • Supplemental Notes:
    • Ihr 73, Hpr
  • Corporate Authors:

    University of Illinois, Urbana-Champaign

    Urbana, IL  USA  61801

    Illinois Department of Transportation

    Division of Highways, 2300 South Dirksen Parkway
    Springfield, IL  USA  62764

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  USA  20590
  • Authors:
    • Lloyd, J P
    • Lott, J L
    • Kesler, C E
  • Publication Date: 1967-9

Subject/Index Terms

Filing Info

  • Accession Number: 00212029
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: Jan 16 1994 12:00AM