Dynamic variation and deterioration mechanism of the friction coefficient between tire and pavement under the icy and snowy circumstances

The accumulation and melting process of snow and ice contamination was simulated in an advanced environmental cabin. The pavement surface condition was monitored using the Vaisala mobile detector, and the friction coefficient between the tire and pavement was measured with the T2GO friction tester. The dynamic variation of the friction coefficient and its deterioration mechanism under various conditions were analyzed. Results show that after a thin ice layer develops on the surface of the coarse aggregate, the cohesion friction component decreases rapidly. Then, as the ice coverage widens, the hysteresis friction component decreases considerably. When the coverage rate of the ice layer reaches 100% and the thickness reaches 0.2–0.3 mm, the friction coefficient decreases to 0.2. In the process of snow accumulation, the friction coefficient is maintained at 0.43–0.45. As the snow layer is soft and easy to compact, the tire rubber can be embedded onto it; even if the thickness can sufficiently cover the macrotexture of the pavement, the hysteresis friction component can be maintained at a high level. In the early stage of snow melting, an ice layer forms on the snow layer's surface, which reduces the friction coefficient to 0.2.