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A chemical approach to the problem of alkali-reactive carbonate aggregates

✍ Scribed by M.A. Pagano; P.D. Cady


Publisher
Elsevier Science
Year
1982
Tongue
English
Weight
569 KB
Volume
12
Category
Article
ISSN
0008-8846

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✦ Synopsis


Refereed) (Received Jan. 22; in final form July 27, 198].)

ABSTRAC~

This paper presents the results of a laboratory investigation of postulated mechanisms and potential remedial measures involving alkali carbonate reaction in concrete. This reaction involving certain carbonate (limestone) aggregates when used with high alkali cement has resulted in distress (cracking) of concrete pavements and slabs.

The observed distress has been attributed to dedolomitization of the aggregates and osmotic pressures.

This study was conducted to determine whether a chemical approach to the problem could reduce the expansion to acceptable levels.

The results were encouraging. Expansion was reduced by as much as 50% using two common chemical substances, lithium carbonate and ferric chloride, introduced into a high alkali portland cement concrete made with a very reactive coarse aggregate, Gull River limestone from Kingston, Ontario, Canada. Another substance, dimethylsulfoxide, was tested also, with insignificant changes in measured expansion.


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