THE MECHANISM OF FATIGUE IN CEMENT PASTE AND PLAIN CONCRETE

AN INVESTIGATION WAS CONDUCTED TO DETERMINE THE FATIGUE BEHAVIOR OF CEMENT PASTE LOADED IN AXIAL COMPRESSION AND THE FATIGUE BEHAVIOR OF THE PASTE WHEN DILUTED WITH AGGREGATE. CEMENT PASTES WERE MADE WITH WATER-CEMENT RATIOS OF 0.70 AND 0.45 BY WEIGHT AND THESE SAME WATER-CEMENT RATIOS WERE USED IN CONCRETES CONTAINING NATURAL AGGREGATES AND CONCRETES CONTAINING SYNTHETIC AGGREGATES. CYLINDRICAL SPECIMENS, 2 IN . IN DIAMETER BY 4 IN. IN HEIGHT, WERE USED FOR EVALUATING THE CONCRETES. SPECIMENS WERE TESTED IN A SATURATED CONDITION AND AT MOISTURE CONTENTS LESS THAN SATURATION. OVER 500 SPECIMENS WERE TESTED STATICALLY IN UNCONFINED COMPRESSION AND OVER 150 SPECIMENS WERE TESTED IN UNCONFINED COMPRESSION AT SPECIFIC STRESS LEVELS AT A SPEED OF 1000 CPM . IT WAS FOUND THAT THE FATIGUE BEHAVIOR OF CEMENT PASTE IS SENSITIVE TO CHANGES IN THE WATER-CEMENT RATIO OF THE PASTE AND TO CHANGES IN THE MOISTURE CONTENT OF THE PASTE. WITHIN THE LIMITS OF THE INVESTIGATION, THE FATIGUE CHARACTERISTICS OF PLAIN CONCRETE ARE APPARENTLY GOVERENED PRIMARILY BY THE FATIGUE CHARACTERISTICS OF THE CEMENT PASTE. THE FATIGUE MECHANISM PROPOSED FOR CEMENT PASTE AND PLAIN CONCRETE IS BASICALLY THE SAME; I.E., FATIGUE FAILURE OCCURS BECAUSE SMALL CRACKS FORM AND PROPAGATE IN THE CEMENT PASTE UNDER REPEATED APPLICATIONS OF LOADS LESS THAN THE STATIC FAILURE LOAD. THE RESULTING CRACK PATTERN WEAKENS THE SECTION TO THE POINT WHERE IT CANNOT MAINTAIN THE APPLIED LOAD. THE DEVELOPMENT OF THIS DAMAGING CRACK PATTERN DEPENDS PRIMARILY ON THE WATER-CEMENT RATIO OF THE CEMENT PASTE AND THE PRESENCE OF SHRINKAGE STRESSES IN THE CEMENT PASTE. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrr/1967/210/210-004.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Mechanical Properties of Concrete and presented at the 46th Annual Meeting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Antrim, John D
• Conference:
  • Symposium on concrete strength, 1966, Washington, DC, USA
• Publication Date: 1967

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 95-107
• Monograph Title: A Symposium on Concrete Strength
• Serial:
  • Highway Research Record
  • Issue Number: 210
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Aggregates; Artificial aggregates; Axial compression; Cement; Concrete; Cracking; Dilution; Fatigue (Physiological condition); Fatigue tests; Moisture content; Natural aggregates; Pastes; Percent saturation; Shrinkage; Specimens; Static tests; Stresses; Water cement ratio
• Old TRIS Terms: Unconfined compression tests
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00212322
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Feb 2 1994 12:00AM