Finite difference model for predicting road surface ice formation based on heat transfer and phase transition theory

Icy pavement surface significantly reduces the skid resistance of roads, and is an important cause of traffic accidents in winter. Reliable road surface icing prediction models are of great significance for decision making in winter road maintenance. This paper developed a finite difference model for predicting road surface ice formation based on heat transfer and phase transition theory. The input data included the meteorological data and road material properties. The output of the model included not only the road surface temperature, but also the road surface condition and ice thickness. To achieve this, the governing equation and boundary conditions were established based on the heat transfer theory. The energy exchanges during the transformation between ice and water were considered by calculating the latent heat based on the phase transition theory. The finite difference method was used to solve the above heat transfer problem. A series of laboratory experiments were designed and conducted to verify the accuracy of the prediction model. And an equation was established to estimate the time required for all surface water to condense into ice when necessary climatic factors were available. With the validated model, the effects of road materials and climatic factors on pavement surface ice formation were analyzed. The results show that cement concrete pavements are more likely to freeze than asphalt concrete pavement. Pavement consisted of a low-conductivity bottom layer, and high-conductivity surface and middle layers, is more suitable for preventing road surface ice in winter. The prediction model is useful for transportation agencies to understand the mechanism of road ice formation and ensure traffic safety in winter.