Corrosion Effects of Municipal Anti-icing and De-icing Programs

Abstract Anti-icing and de-icing chemicals are commonly used for winter road maintenance in areas that experience icy conditions. Anti-icing is a preventative strategy, while de-icing is a reactive strategy. In many jurisdictions, these two strategies are used in combination to improve the overall effectiveness of winter road maintenance programs. The City of Edmonton currently utilizes a combination of sodium chloride and sand as a de-icing program. To improve the economics and effectiveness of the overall winter road maintenance program, the City of Edmonton began a pilot program that utilizes corrosion-inhibited calcium chloride brine as an anti-icing agent. Anti-icing is utilized as a tool in the City of Edmonton’s Vision Zero safety goal which identifies bare pavement as the highest standard to promote safety. However, there is public concern that the anti-icing pilot program is causing increased corrosion to metal infrastructure and vehicles. This study investigates the corrosion effects of the anti-icing pilot program through field and laboratory testing of metal coupons. The field testing produced inconclusive results due to insufficient time in the field and varied/atypical application of calcium chloride brine in winter 2018/2019. The laboratory testing results showed that the amount of corrosion observed varied due to a myriad of factors. Generally, increased exposure to corrosive solutions and environments led to an increased amount of corrosion observed. Overall, the results did not indicate that the pilot program was more or less corrosive than the existing program. It is recommended that additional corrosion prevention methods be applied to metal surfaces exposed to corrosive environments, such as those found on Edmonton roads. Further research should be conducted to investigate the many factors that can influence the corrosive effects of anti-icing and de-icing programs.