Effects of Deicing and Anti-icing Materials on Resistance of Warm Mix Asphalt

The routes exposed to snow and rain, with a chance of freezing, need de-icing due to the possibility of exploitation of the route and protection against structural damage. Lack of maintenance and de-icing leads to swelling of the surface, contractile cracks, expansion of existing cracks, separation of the pavement layers and in some cases separation of the grains. Calcium chloride, magnesium chloride, sodium chloride and urea can be used as de-icing and liquid anti-icing materials. In using the above materials, in addition to the ecological and economical aspects, damages caused to asphalt surface due to the close contact with these materials should be evaluated. The aim of this study was laboratory investigation of the effect of using the above materials on asphaltic-mixture resistance. For this purpose, the prepared samples were cured according to AASHTO T283 and tested for Marshal stability, tensile strength and resilient modulus. Results indicated that deicing with calcium chloride solution in Marshal stability test, calcium chloride and urea solution in tensile strength test, and urea in resilient modulus test has the lowest negative effect. Also, since the mixture is in close contact with pure water and freeze-thaw cycle, it has the highest negative effct on the laboratory samples and this approves and emphasizes the need for proper maintenance and use of anti-icing and de-icing materials. Therefore, considering the negative ecological effects, effective temperature, price of the materials and results of this research, in areas where the temperature is 0 to -10, or -10 to -20 or lower than -20 °C, then urea, magnesium chloride and calcium chloride can be used as de-icing material, respectively, to have the lowest damages to asphalt pavement.