Extending low-temperature differential scanning calorimetry from paste to mortar and concrete to quantify the potential for calcium oxychloride formation

Calcium chloride-based deicing salts can react with calcium hydroxide in concrete pavements, resulting in the formation of calcium oxychloride. The formation of calcium oxychloride can cause damage in the pavements, especially at the joints. Recently, it has been shown that low-temperature differential scanning calorimetry can be used to measure calcium oxychloride contents in cement pastes exposed to calcium chloride. This article explores the extension of the low-temperature differential scanning calorimetry test method from applications on ground paste to ground mortar and concrete. Specifically, the influence of dilution due to the aggregate volume causes the measured amount of calcium oxychloride to be smaller in mortar and concrete than the pastes. To successfully measure the amount of calcium oxychloride, a higher powder-liquid ratio is used in concretes as compared to pastes. Low-temperature differential scanning calorimetry can successfully be used to measure the amount of calcium oxychloride in ground mortars and concrete; however, there is an increase in the variation of the measurement, and, as such, it is recommended that the average of three tests should be considered as a test specimen.