Alkali-aggregate reactions in Ontario

Abstract

In Ontario, two types of alkali-aggregate reaction exist. Each type is evaluated using different tests. Over the past few years, new tests have been introduced to replace some existing test methods. The new tests are faster and more reliable. Preventive measures such as the use of low-alkali cement and supplementary cementing materials, while they are effective, have not been extensively used with reactive aggregate in Ontario. Beneficiation or selective extraction is used with some potentially reactive aggregates.Key words: alkali-aggregate reaction, concrete, cracking, Ontario, structures.