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Description: The objective of this program is to critically review existing performance specifications and test methods on sulfate attack, to provide the technical basis for improved performance standards, and to provide criteria for evaluation, selection, and use of concrete materials for sulfate attack resistance.
The approach taken is based on procedures described in ASTM E 632. The performance of concrete under sulfate attack needs to be divided into several phenomena and therefore several tests had to be developed. The various phenomena are: Concrete properties: absorption and diffusion of sulfate (resistance to the ingress of sulfate solutions).
Cement paste properties: chemical reaction between the hydration product and the sulfate ions. In the literature this is referred as chemical attack [2].
Influence of environmental conditions: type of immersion (constant, partial, or cyclic) and temperature. In the literature, this is referred as physical attack [2].
Therefore the tests that were developed are:
Absorption of water by a concrete specimen. This test was submitted to ASTM and approved in 2004 as ASTM C 1585.
Diffusion of sulfate in saturated specimens. A methodology to modify existing methods is given.
A specimen test to determine the cement's resistance to sulfate attack, which is three to five times shorter than current tests.
A test to determine the resistance to sulfate attack when a concrete is not totally immersed in the solution.
This report also provides guidelines on how to combine the results of all these tests to determine a concrete's sulfate resistance.
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