The Influence of Calcium Chloride Deicing Salt on Phase Changes and Damage Development in Cementitious Materials
Yaghoob Farnam, Sarah Dick, Andrew Wiese, Jeffrey M. Davis, Dale P. Bentz, Jason Weiss
The conventional CaCl2-H2O phase diagram is often used to describe how a calcium chloride behaves when it is used on a concrete pavement undergoing freezing and thawing damage. However, the existence of additional chemical compounds in concrete can alter the CaCl2-H2O phase diagram. This study shows that the Ca(OH)2 from Portland cement can add another phase to the CaCl2-H2O phase diagram. The Ca(OH)2 reacts with CaCl2 and H2O resulting in the formation of calcium oxychloride. The formation of the calcium oxychloride is expansive and can produce damage in concrete at temperatures above freezing. It can also cause a significant decrease in fluid ingress into concrete. A phase diagram is proposed for Ca(OH)2-CaCl2-H2O; and the temperature at which calcium oxychloride forms is determined. For concentrations greater than about 11.3 % CaCl2 by mass, it is found that calcium oxychloride forms rapidly and is stable at room temperature (23 °C).
, Dick, S.
, Wiese, A.
, Davis, J.
, Bentz, D.
and Weiss, J.
The Influence of Calcium Chloride Deicing Salt on Phase Changes and Damage Development in Cementitious Materials, Cement and Concrete Composites, [online], https://doi.org/10.1016/j.cemconcomp.2015.09.006, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916314
(Accessed December 9, 2023)