The influence of runway de-icing agents on the durability of asphalt concrete pavements for airfields

Results and experience from a Norwegian/Swedish joint project on the detrimental effect of runway de-icing agents on asphalt pavements are presented. Exposure of airfield pavements in a weather simulator forms a part of the project.Laboratory studies of bituminous binders and asphalt concrete have been performed. A certain softening effect was observed in bitumen. The studies found that resistance to de-icing agents increases with increasing hardness of the conventional bitumen. The effect becomes more pronounced with time, temperature and concentration of the chemical. Among the de-icing agents tested, potassium formate and sodium formate had the greatest influence on the binder.Other significant parameters concerning the de-icing agent are the pH value and the surface tension properties of the solution.A method has been developed for surface tensile strength. The method has been used for evaluating the pavements in the weather simulator test.