Using Low-Temperature Differential Scanning Calorimetry to Quantify Calcium Oxychloride Formation for Cementitious Materials in the Presence of Calcium Chloride

• Published in: Advances in civil engineering materials 2016-12, Vol.5 (2), p.142-156
• Main Authors: Monical, J., Villani, C., Farnam, Y., Unal, E., Weiss, W. J.
• Format: Article
• Language: English
• ISSN: 2165-3984; 2379-1357; 2165-3984
• DOI: 10.1520/ACEM20150024

Whereas many concrete pavements have exhibited service lives of 30 to 50 years, a portion of these pavements in regions that are exposed to snow, ice, and salt have shown premature distress at the joints. This distress has been observed to occur between 5 and 20 years and requires extensive repair of an otherwise well-functioning pavement. Although there are several potential mechanisms that can lead to this deterioration, a reaction can occur between calcium chloride coming from deicing salt (CaCl2) and the tricalcium aluminate (C3A) and/or calcium hydroxide (CH) in the cementitious matrix. This paper describes the development of a test method that can be used to evaluate the potential for a cementitious binder to react with the calcium chloride deicing salts to form calcium oxychloride (the reaction between CaCl2 and CH). The test method enables the quantity of calcium oxychloride to be determined for each binder system. The results indicate that the amount of calcium oxychloride can be reduced with the replacement of cement with supplementary cementitious materials (fly ash, slag, silica fume, etc.). It is anticipated that the proposed test method could be used to better understand the role of binder chemistry on the calcium oxide formation and to optimize the binder composition to reduce the calcium chloride formation to an acceptable level and ultimately reduce the risk for deterioration.