Mitigation of Delayed Ettringite Formation in Laboratory Specimens

Abstract

The objective of this study was to determine if the growth of delayed ettringite formation (DEF) in existing concrete can be reduced or even prevented with commercial products. Additionally, the objectives were to determine if externally treating concrete specimens with water repellents and crystal growth inhibitors will decrease DEF-related expansion. The research required casting laboratory specimens for expansion and weight measurements, for strength testing, and for scanning electron microscope (SEM). Three of the four products, ChimneySaver, Dequest 2060S, and Good-Rite K752, reduced concrete expansion and weight change when compared to the control set. The study indicates that ettringite may have to be identified and mitigated early to prevent deleterious effects.