Title:
An Alkali-Silica Reaction Preventing Chemical Admixture
Author(s):
Frank Ong, Bailey Farleman, Mark Bury, Paul Seiler, and Eric Castner
Publication:
Symposium Paper
Volume:
369
Issue:
Appears on pages(s):
143-158
Keywords:
Alkali–silica reaction (ASR); Calcium nitrate; Compressive strength; Expansion
DOI:
10.14359/51750728
Date:
5/1/2026
Abstract:
Alkali–silica reaction (ASR) is a major concrete durability problem. The occurrence of ASR results in significant maintenance and reconstruction costs to concrete infrastructures all over the world. Current market solutions are not always sustainable, such as hauling non-reactive aggregates or fly ash from long distances; or use of a lithium-based admixture that has availability, and lead time challenges. The current article will present an ASR mitigating admixture, which is based on the abundant water-soluble calcium salts, such as Ca(NO3)2. The current ASTM C1567 test method is not suitable for evaluating this new ASR mitigating technology due to the potential for leaching of soluble Ca(NO3)2 into the soak solution. A slight modification to the ASTM C1567 test using additional Ca(NO3)2 in soak solution to buffer any potential leaching has been developed for evaluating this new ASR preventing technology. Twenty-seven aggregates have been evaluated with this innovative technology. Depending on the reactivity of the aggregate and the alkali content of the cement, the dosage of this new admixture required to inhibit ASR ranges from 32 to 81 mL/kg of cement for aggregates tested. This new admixture is formulated to be set neutral, provides water reduction, and significantly improves the compressive strength of concrete in addition to preventing ASR expansion.
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