ABSTRACT
Institute for Research in Construction, National Research Council of Canada, Building M20, Ottawa, Canada, K1A 0R6
1. INTRODUCTION
Test methods such as the mortar bar method (ASTM C227 [1]) and the concrete prism test method (CSA A 23.2-14 [2]) which have traditionally been used to evaluate the potential reactivity of aggregates are no longer considered satisfactory as they take too long to complete. The chemical method, (ASTM C289 [3]) while it is rapid, it is not suitable for use with all types of aggregates and and furthermore because it does not give an estimate of the expansion potential of the aggregate, is not suitable as an acceptance test. In the evaluation of new rapid test methods it is essential that the results obtained are compared with those of reliable standard tests, or with field performance; the latter is often not available. Recent research [4] has shown that standard tests such as the mortar bar method ASTM 0,2211 may seriously underestimate the expansiveness of an aggregate; there is thus a need to refine existing standard tests, and to the develop new methods. Both the above topics will be addressed in this paper.
