Effects of Anti-Icing Agents on the Durability of Concrete

Different anti-icing agents are used in various locations in Ontario to meet the specific climate needs of the area in order to minimize, or help remove, snow and ice build-up. These anti-icing agents are generally applied in liquid form and, due to their low freezing temperatures, are able to stay liquid, thus also allowing them to penetrate concrete structures. It has been shown in previous studies that the cations of some of the solutions can react with the cementitious materials to form precipitates of expansive nature. In this project, concrete exposed to the different solutions has been subjected to freezing and thawing both in laboratory tests and in outdoor exposure and to compression testing. However, the salts prevented freezing at the lowest temperatures tested. Therefore, it has been observed that reactions with the calcium and magnesium chlorides can have a positive effect at early ages but a potentially detrimental effect over the long term. The penetration of salt into the dry concrete was determined to be very fast and resulted in a rapid initial increase in the concrete compressive strength but little subsequent strength gain, whereas the strength of concrete exposed to water continues to increase over a longer period.