EX SITU LEACHING MEASUREMENT OF CONCRETE ALKALINITY

Evidence exists that as the pH of concrete pore water increases, the chloride-induced corrosion threshold also increases. On the other hand, high pore water alkalinity promotes a reaction with certain alkali-reactive aggregates, which leads to the expansion and possibly the cracking of concrete. This article reports on a new technique involving ex situ leaching (ESL) of concrete particles in deionized water. The authors used chemical analysis of the resulting leachant to determine the concrete pore water alkalinity. The authors report their results using a water-to-concrete powder ratio no higher than 1 and a leaching time no less than 3 days. The concrete pore water hydroxide ion concentration was then calculated. The authors concluded that concrete pore water hydroxide ion was proportional to the cement equivalent alkali content but relatively insensitive to the concrete water-to-cement ratio. Additional comparisons either directly or indirectly confirmed the validity of the proposed method. The authors caution that applicability of the ESL method, as proposed, to concrete containing pozzolans or highly soluble inorganic salts (or both) needs to be further explored.

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    Elsevier

    The Boulevard, Langford Lane
    Kidlington, Oxford  United Kingdom  OX5 1GB
  • Authors:
    • Li, Li
    • Nam, Jeong-Hee
    • Hartt, W H
  • Publication Date: 2005-2

Language

  • English

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Filing Info

  • Accession Number: 00989027
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 29 2005 12:00AM