Laboratory investigation of effect of deicing chemicals on airfield asphalt concrete pavements materials

Every year, large amounts of deicers/anti-icers are used for snow and ice control on Canadian highway and airfield pavements. Due to the potential corrosive effect of road salts on aircraft, Canadian airport authorities have adopted alternative deicing chemicals that are less corrosive. However, the potential deleterious effects of these alternative deicers on pavement materials need to be quantified and compared with those caused by conventional road salt. This paper presents the results of an investigation to assess the destructive effect of ordinary road salt, as well as four alternative runway deicers, and evaluate the impact they may have on the durability of asphalt concrete pavements. Core samples were immersed in solutions of road salt as well as in solutions made of Urea, Sodium Formate, Potassium Acetate, and Sodium Acetate, and then subjected to 50 freeze-thaw cycles. Two types of control samples were considered by using dry samples, which were left at room temperature, and samples that were immersed in distilled water and subjected to the same number of freeze-thaw cycles. The testing program involved weighing the samples at the end of every five cycles to establish the trend of weight change. The samples were then tested for their indirect tensile strength, where half the samples were tested after 25 cycles and the other half after the completion of the 50 cycles. The results show that all samples, including those immersed in distilled water, have experienced some damage and loss of strength relative to the control dry samples. When compared with the specimens in distilled water, only those immersed in Urea solution suffered a loss of strength and elasticity.