Superhydrophobic Coatings on Asphalt Concrete Surfaces: Toward Smart Solutions for Winter Pavement Maintenance

Millions of dollars are annually spent for ice or snow removal from the roadways and airport paved surfaces in cold regions. The presence of snow or ice on paved areas can cause traffic accidents and financial loss because of flight cancellations or delays. For mitigating winter pavement maintenance issues, the use of superhydrophobic (super-water-repellent) coating techniques is gaining attention as a smart and cost-effective alternative to traditional snow and ice removal practices. This study focuses on creating, characterizing, and evaluating innovative superhydrophobic coatings on asphalt concrete surfaces for ice- and snow-free flexible pavement applications. The layer-by-layer (LBL) method was used to create an asphalt concrete surface coating with polytetrafluoroethylene (PTFE) as a well-known super-ice- and super-water-repellent material. Superhydrophobicity and skid resistance of the coated asphalt concrete surface were characterized by the water contact angle, the work of adhesion, and the coefficient of friction at the microtexture level. These properties were evaluated for test variables including spray times and dosage rates of PTFE under a statistical design–based experimental test program. The measurement results indicate that uses of the LBL method for spray-depositing the PTFE particles and the microtribometer for measuring coefficient of friction at the microtexture level are promising methods for creating and characterizing superhydrophobic coatings on asphalt concrete. The results of statistical analyses indicate that the spray time and dosage of PTFE significantly affect the ability of a coated flexible pavement to be icephobic or superhydrophobic and skid resistant.