Impact of Airport De-Icing Chemicals and Freeze-Thaw on Rutting Resistance of Asphalt Mixture in Canada

Acetate-based ice control chemicals have been shown to have less environmental impact compared with traditional de-icing salts. However, their impact on the asphalt pavement’s performance has been underestimated and has drawn the attention of pavement engineers. This study was undertaken to evaluate the effect of de-icing chemicals (potassium acetate) and the freeze-thaw cycle on the rutting resistance of asphalt mixtures. Two types of airport pavement mixtures (AS and AB) and three roadway mixtures (HL3, HL3 HS, and HL1) were tested through the Hamburg wheel tracking test (HWTT) under three different treatments for the testing specimens: treated with potassium acetate solution, with one freeze-thaw cycle; and treated with potassium solution and one freeze-thaw cycle, respectively. The results show that potassium acetate solution and the freeze-thaw cycle can significantly affect the rutting resistance of all tested mixtures, and potassium acetate might have the potential to induce stripping damage on asphalt mixtures. A combination of de-icing treatment and the freeze-thaw cycle can potentially mitigate the stiffness compromise caused by their sole impact. Asphalt binder type, asphalt content, and different treatment methods have a statistical effect on the rutting resistance of asphalt mixture applied both on airside and roadway pavements.