COOPERATIVE EXAMINATION OF CORES FROM THE MCPHERSON TEST ROAD
CORES WERE TAKEN FROM THE MCPHERSON TEST ROAD FOR EXAMINATION OF THE CONCRETE. THE CORES WERE SHOT-DRILLED FROM THE MIDDLE OF THE SLAB AT ABOUT THE MID-POINT OF EACH EXPERIMENTAL SECTION IN THE NORTH-BOUND LANE. EXAMINATIONS OF WEDGES OF CORES FROM SPECIFIED SECTIONS OF THE TEST ROAD AGREED WITH EVIDENCE OF ALKALI-AGGREGATE REACTION IN THE FOUR CORES. WETTING THE CORES SHOWED THAT NONE HAD EXHAUSTED ITS REACTIVE POTENTIAL. THE EVIDENCE OF DISTRESS IN THE CORES WAS RANKED IN THE SAME ORDER AS THE CONDITION OF THE PAVEMENT SECTIONS SAMPLED. CHEMICAL ANALYSES INDICATED THAT SULPHATE ATTACK WAS NOT A FACTOR. THE BOND BETWEEN CEMENT PASTE AND THE POLISHED GRANITE AND FELDSPAR AND SMOOTH QUARTZ WAS POOR. BOND BETWEEN CEMENT PASTE AND THE LIMESTONE OF THE SWEETENED CORES WAS EXCELLENT. A SUMMARY OF THE EXAMINATIONS INDICATED THAT THE AGENCIES CAUSING DISTRESS ARE NOT RESTRICTED TO ONE CEMENT OR ONE AGGREGATE OR ONE CEMENT-AGGREGATE COMBINATION. THE CEMENT WHICH SHOWED EXCESSIVE EXPANSION IN TESTS BEFORE THE ROAD WAS BUILT, PERFORMED WELL, WHEREAS THE CEMENT WHICH SHOWED THE LEAST EXPANSION IN PRECONSTRUCTION TESTS, SHOWED THE MOST CRACKING IN THE ROAD. THE REVERSAL MAY BE EXPLAINED BY DIFFERENCES IN AVAILABILITY OF WATER IN THE TEST AND IN THE PAVEMENT. ALKALI-AGGREGATE REACTION IS INVOLVED TO VARYING DEGREES IN SAND-GRAVEL CONCRETE IN THE FIELD AND LABORATORY TESTS, BUT THE DEGREE OF THE REACTION DOES NOT CORRELATE WITH OBSERVED DISTRESS. THE DELETERIOUS EXPANSION PRODUCED BY SAND-GRAVEL AGGREGATE UNDER CERTAIN CONDITIONS IS NOT SUBJECT TO CONTROL BY REDUCTION OF ALKALI CONTENT OR MAGNESIA CONTENT OF CEMENT. RESEARCH IS STILL NEEDED TO ESTABLISH THE FUNDAMENTAL CAUSE OF THE DELETERIOUS ACTION OF THE CEMENT- AGGREGATE COMBINATIONS, INCLUDING THE SAND-GRAVEL.
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Supplemental Notes:
- Vol 39, pp 205-216, 7 TAB, 15 REF. 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:
- Mather, K
- Mielenz, R C
- Publication Date: 1960
Media Info
- Media Type: Digital/other
- Monograph Title: Proceedings of the Thirty-Ninth Annual Meeting of the Highway Research Board, Washington, D.C., January 11-15, 1960
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Serial:
- Highway Research Board Proceedings
- Volume: 39
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Alkali aggregate reactions; Concrete pavements; Core samples; Defects; Deleterious materials; Expansive cement; Experimental roads; Pavement distress; Pavements
- Old TRIS Terms: Cores
- Subject Areas: Highways; Pavements;
Filing Info
- Accession Number: 00207360
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Sep 19 1971 12:00AM