POZZOLANS IN SAND-GRAVEL AGGREGATE CONCRETE
SAND-GRAVEL AGGREGATES PRODUCED OVER A LARGE AREA OF NEBRASKA ARE REACTIVE WITH CEMENTS IN CONCRETE STRUCTURES AND PAVEMENTS, GENERALLY CAUSING EXCESSIVE EXPANSION AND "MAP" CRACKING. SOME POZZOLAN MATERIALS WILL INHIBIT SEVERE CEMENT-AGGREGATE REACTION WHEN INTERGROUND WITH THE CEMENT OR WHEN USED TO REPLACE PART OF THE CEMENT IN A CONCRETE MIXTURE. TESTS WERE MADE ON A SERIES OF LABORATORY MIXES AND ON FIELD EXPERIMENTAL SECTIONS TO DETERMINE THE PHYSICAL CHARACTERISTICS AND DURABILITY OF AIR-ENTRAINED CONCRETE IN WHICH A POZZOLAN MATERIAL WAS INTERGROUND WITH THE CEMENT AND ALSO AIR-ENTRAINED CONCRETE IN WHICH PART OF THE CEMENT WAS REPLACED WITH FLYASH. THESE TESTS INDICATED THAT THE POZZOLAN CONCRETE HAD BETTER WORKABILITY AT NORMAL TEMPERATURES, SLIGHTLY LOWER EARLY STRENGTH, BUT USUALLY HIGHER STRENGTH AT LATER AGES AND IMPROVED DURABILITY IN FREEZING AND THAWING. THE EXPANSION OF CONCRETE BEAMS TESTED IN A WETTING-AND-DRYING TEST AND OF MORTAR BARS TESTED IN SEALED CONTAINERS AT 100 F. WAS DEFINITELY LESS OR WAS COMPLETELY INHIBITED IN THE CONCRETES OR MORTARS MADE WITH THESE POZZOLANS. THE CONCRETE MADE WITH THE MANUFACTURED POZZOLANIC CEMENT REQUIRED MORE MIXING WATER FOR A WORKABLE MIX WHICH RESULTED IN LOWER STRENGTH AND HIGHER ABSORPTION. /AUTHOR/
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Supplemental Notes:
- Vol 32, pp 317-328, 11 FIG, 3 TAB, 10 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:
- Bollen, R E
- Sutton, C A
- Publication Date: 1953
Media Info
- Media Type: Digital/other
- Monograph Title: Proceedings of the Thirty-Second Annual Meeting of the Highway Research Board, Washington, D.C., January 13-16, 1953
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Serial:
- Highway Research Board Proceedings
- Volume: 32
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Air entrained concrete; Alkali aggregate reactions; Concrete; Durability; Expansion; Fly ash; Pozzolan; Sandy gravels; Strength of materials; Workability
- Subject Areas: Geotechnology; Highways; Materials;
Filing Info
- Accession Number: 00217878
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Aug 15 1971 12:00AM