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Preventive measures to counteract expansion of concrete containing alkali-reactive aggregates

From National Research Council Canada

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DOIResolve DOI: https://doi.org/10.4224/40001923
AuthorSearch for: 1
Affiliation
  1. National Research Council of Canada
FormatText, Technical Report
SubjectConcrete; concrete admixtures; alkalinity; cement; expansion; crackings (breaking); aggregate; alkali; beneficiation; blast furnace slag; cement; concrete; cracking; exposure; fly ash; moisture; pozzolan; silica fume; structural
Abstract
Alkali-aggregate reaction causes expansion and cracking of concrete structures exposed to high humidity. Deterioration is much exacerbated if de-icing salts are used on the concrete. The expansion, caused by reaction between the alkaline pore solution and certain minerals in the aggregate, can be prevented or minimized by a number of methods. The best solution is to use an alternative, non- reactive aggregate. Beneficiation of the aggregate by selective quarrying is often effective in eliminating reactive material, particularly in horizontally layered carbonate quarries. Limiting the alkali content of the concrete, by using either a low-alkali cement or a mix with a low cement content, or both, may also be effective in preventing premature deterioration of concrete containing reactive aggregates. Replacement of part of the cement with a pozzolan of proven effectiveness is an alternative method of preventing deleterious expansion. Major structures made with concrete containing reactive aggregate should be designed so as to prevent water from ponding on them. It is also important to establish an ongoing maintenance programme to keep joints sealed and cracks grouted, to prevent water from entering the structure.
Publication date
PublisherNational Research Council of Canada. Division of Building Research
Series
  • DBR Paper, no. DBR-P-1131.
Reprint of
  • Durability of Building Materials (1983): 363–376.
LanguageEnglish
Peer reviewedYes
NRC numberNRCC 22632
NRC-IRC-2097
NPARC number20386729
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Record identifier2d9cf60a-07fb-404c-84b4-59488d67092a
Record created2012-07-25
Record modified2024-03-22
Date modified: