Preparation of temperature-controlled salt storage materials and application in ultra-thin friction course

Salt-storage anti-icing ultra-thin friction courses (SAUTFC) are an effective preventive maintenance treatment to improve road performance and ensure the safety of winter pavement traffic. However, the addition of salt storage agents and precipitates decreases the engineering and anti-icing performance. Hence, this study used the temperature-controlled salt-controlled-release deicer (SCD) to prepare and characterize SAUTFC. The microstructure and properties of SCD were investigated. The SAUTFC preparation procedures and content of SCD were determined. Subsequently, the interlayer bonding properties, skid resistance performance, and anti-freeze properties were evaluated. The results indicated that SCD with a glass transition temperature of −4 ℃ can control the precipitation of salts before the winter. The SCD dosing in SAUTFC is 75% of the replacement mineral powder, and interlayer shear strength reaches its maximum when the application rate of the tack coat is 1 kg/m². The wear resistance of SAUTFC was investigated by accelerated loading tests, which showed that SAUTFC still provides excellent skid resistance after four years. In addition, the SAUTFC accelerates the melting rate of snow and ice and decreases the bonding force between ice and the specimen surface, with excellent anti-freeze durability. Therefore, the application of salt storage materials in ultra-thin friction courses to provide active snow and ice removal on winter pavements is feasible.