AN INTERPRETATION OF THE RESULTS FROM VIBRATING-WIRE STRAIN GAUGES IN FRESH CONCRETES
A PROGRAM OF TESTS CONCERNING CREEP, SHRINKAGE, AND TEMPERATURE MOVEMENTS IN HIGHWAY BRIDGES IS BEING CONDUCTED BY THE BRIDGES SECTION OF THE DESIGN DIVISION OF THE ROAD RESEARCH LABORATORY. THIS PAPER DESCRIBES THE INTERPRETATION OF THE READINGS FROM ACOUSTIC STRAIN GAUGES IN FRESH CONCRETE, UP TO THE TIME THE HEAT OF HYDRATION IS DISSIPATED. CHARACTERISTICS OF THE VIBRATING-WIRE GAUGE ARE DESCRIBED, TOGETHER WITH THE RESULTS OF TWO LABORATORY EXPERIMENTS AND THREE FULL-SCALE SITE INVESTIGATIONS. THE RESULTS SHOW THAT USUALLY EXPANSIONS TAKE PLACE DURING THE HYDRATION OF TYPICAL BRIDGE CONCRETES AS USED IN THE UNITED KINGDOM. THESE WERE MANUFACTURED FROM NORMAL PORTLAND CEMENT HAVING WATER/CEMENT RATIOS IN THE RANGE 0.38 TO 0.40. ALSO DISCUSSED ARE THE STRAIN CHANGES THAT OCCUR ON COOLING DURING THE DISSIPATION OF THE HEAT OF HYDRATION IN FULL- SCALE STRUCTURES AND CRACKING CAUSED BY DIFFERENTIAL STRAINS ON COOLING. THE EFFECT OF USING A LIMESTONE AGGREGATE HAVING A LOW COEFFICIENT OF EXPANSION IS SHOWN, AND IT IS DEMONSTRATED THAT COOLING AFTER HYDRATION PRODUCES A SELF- STRAINING SET OF FORCES WITHIN THE CONCRETE, THE REINFORCEMENT BEING IN TENSION TO APPROXIMATELY 3,500 PSI WHILE THE CONCRETE IS IN COMPRESSION. /AUTHOR/
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Supplemental Notes:
- Paper sponsored by Committee on Mechanical Properties of Concrete and presented at the 47th 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.
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Authors:
- TYLER, R G
- Publication Date: 1968
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: pp 1-17
- Monograph Title: Mechanical properties of plastic concrete and pavement thickness measurement
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Serial:
- Highway Research Record
- Issue Number: 218
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Acoustics; Compression; Cooling; Creep; Heat of hydration; Highway bridges; Hydration; Limestone aggregates; Material reinforcement; Measurement; Polymer concrete; Portland cement concrete; Shrinkage; Strain gages; Temperature measurement; Tension; Thermal expansion; Vibration; Water cement ratio
- Old TRIS Terms: Shrinkage tests
- Subject Areas: Highways; Materials;
Filing Info
- Accession Number: 00212646
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Aug 28 1994 12:00AM