Deicing Performance Improvement of Single-Component Polyurethane Pavement Materials

To enhance the deicing performance of polyurethane pavement and minimize its impact on water stability, this study reduces adhesion between ice and polyurethane and improves water stability by adding hydrophobic modifiers. Polycarbodiimide (PCDI), cetyltrimethoxysilane (HDTMS), and hydroxypolydimethylsiloxane (HPDMS) were selected as modifiers. Hydrophobic properties before and after modification were analyzed using contact angle measurements, tensile tests, and atomic force microscopy (AFM). Rubber particles were added to increase the elastic deformation ability of the polyurethane mixture, further improving its deicing performance. The effects of rubber particles on performance were evaluated through uniaxial compression, high-temperature performance, and freeze-thaw splitting tests. Ice layer rupture and oblique shear de-icing experiments verified the improvement in deicing performance. Results showed that HPDMS exhibited the strongest hydrophobicity and the best water resistance among the modifiers, significantly enhancing polyurethane’s mechanical properties after soaking. This improvement was attributed to HPDMS enhancing hydrogen bonding and increasing microphase separation during water-polyurethane reactions. The optimum HPDMS content was 2%, which significantly improved water stability with minimal effect on elastic modulus and high-temperature performance. Increasing the size of rubber particles reduced the elastic modulus, increased porosity, and slightly decreased water stability, while dynamic stability remained largely unchanged. A rubber particle size of 0.6–1.18 mm was recommended based on its ability to enhance elastic deformation and road performance. Deicing tests showed that compared to the unmodified mixture, the freeze-thaw splitting strength ratio of the mixture with 2% HPDMS and 0.6–1.18 mm rubber particles increased by 13.6%. However, rupture work decreased by 41.0%, and oblique shear strength decreased by 74.7%, 58.0%, and 46.8% under three ice thicknesses.