Professor, The Pennsylvania State University, University Park, PA
Throughout its long history, sulfate soundness testing of aggregates has been frequently cited for poor reliability as a predictor of concrete durability. However, its use remains widespread, even to the point of constituting an acceptance test criterion for aggregates. Sodium sulfate soundness tests of coarse aggregates are compared in this paper with freezing and thawing tests of air-entrained concretes containing the aggregates. In one case, sodium sulfate soundness displayed a relationship to durability (freezing and thawing) test results, in a statistical sense, but the level of predictability was poor. In another test series, the level of predictability fell within the range of pure chance.
The attractiveness of sulfate soundness testing is apparently derived from its simplicity and directness. However, it is shown in this paper that a combination of two aggregate property tests, specific gravity and absorption, provide a better predictor of freezing and thawing durability. Furthermore, these two tests are routinely run on aggregates and are even simpler than the sulfate soundness test.
Paper ID: CCA10353J