EVALUATION OF THE QUICK CHEMICAL TEST FOR ALKALI REACTIVITY OF CONCRETE AGGREGATE

SINCE ITS PUBLICATION IN 1947, THE QUICK CHEMICAL TEST FOR ALKALI REACTIVITY OF CONCRETE AGGREGATE HAS BEEN USED BY MANY LABORATORIES, AND THE PROCEDURE WAS ACCEPTED AS A TENTATIVE STANDARD BY THE AMERICAN SOCIETY FOR TESTING MATERIALS IN 1952 (METHOD C 289). THE SIGNIFICANCE AND RELIABILITY OF THE TEST ARE EVALUATED IN THE LIGHT OF EXPERIENCE. AS WAS INDICATED IN THE ORIGINAL PUBLICATION OF THE METHOD, ANOMALOUS RESULTS CAN BE OBTAINED IF CERTAIN ROCKS OR MINERALS ARE PRESENT. MOREOVER, REPRODUCIBILITY OF RESULTS COMMONLY IS NOT SATISFACTORY, PRIMARILY BECAUSE CHEMICAL EQUILIBRIUM IS NOT ESTABLISHED BETWEEN THE SAMPLE AND THE SOLUTION. HENCE, THE CONCENTRATION OF SILICA IN SOLUTION AND THE REDUCTION EFFECTED IN THE ALKALINITY OF THE SOLUTION ARE INFLUENCED BY ALL ASPECTS OF THE PROCEDURE, BOTH DURING AND FOLLOWING THE REACTION PERIOD. IN ORDER TO ELUCIDATE THESE MATTERS, THE FOLLOWING FACTORS WERE INVESTIGATED: (1) PRESENCE IN THE AGGREGATE OF MINERALS EFFECTING EXTRANEOUS REDUCTION OF ALKALINITY, INCLUDING DOLOMITE, ANTIGORITE, AND CALCITE, (2) EFFECT OF AGITATION DURING THE REACTION PERIOD, (3) PRELIMINARY ACID TREATMENT OF SAMPLES TO REMOVE CARBONATES, (4) MEASUREMENT OF PH DURING TITRATION TO DETERMINE THE REDUCTION OF ALKALINITY, (5) MODIFICATION OF FILTERING PROCEDURES, AND (6) VARIATION IN VOLUME AND CONCENTRATION OF THE NAOH SOLUTION. THE RESULTS ARE SUMMARIZED AND DISCUSSED. THE FINDINGS DO NOT JUSTIFY MODIFICATION OF THE TEST PROCEDURE AT THIS TIME. HOWEVER, IT IS RECOMMENDED THAT A PETROGRAPHIC EXAMINATION OF THE AGGREGATE BE PERFORMED AS A GUIDE TO EVALUATION OF THE RESULTS OF THE CHEMICAL TEST. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/171/171-001.pdf
• Supplemental Notes:
  • No 171, pp 1-15, 7 FIG, 5 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.
• Authors:
  • Mielenz, Richard C
  • Benton, Elton J
• Publication Date: 1958

Media Info

• Media Type: Digital/other
• Pagination: 15p
• Monograph Title: Alkali-aggregate reaction
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 171
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Alkali aggregate reactions; Carbonates; Chemical reactivity; Chemical tests; Concrete aggregates; Filtration; Geological surveying; Mineral aggregates; Petrography; pH value; Reduction (Chemistry); Silica; Sodium hydroxide; Solutions (Chemistry)
• Old TRIS Terms: Petrographic investigations; Solutions
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00217762
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Sep 16 1994 12:00AM