## 4 Results and Discussion
### Effect of Deicing Salt Concentration
Figure 10: Effect of deicing salt concentration on pavement surface temperature: (**a**–**i**), respectively, show the results under different combinations of air temperature and wind speed, with values of (\(-10\)\({}^{\circ}\)C, 2 m/s), (\(-10\)\({}^{\circ}\)C, 4 m/s), (\(-10\)\({}^{\circ}\)C,  
The experimental results clearly demonstrate that the concentration of deicing salt significantly influences the cooling of airport pavement surfaces and delays the onset of icing. As the concentration of deicing salt increases, the pavement surface temperature decreases more markedly, and the icing onset time is notably prolonged. This phenomenon primarily occurs because the deicing salt lowers the freezing point of the surface solution. Consequently, as the concentration of deicing salt increases, the freezing point of the  
Figure 11: Variation in the icing onset time vs. the salt concentration and wind speed: (**a–f**), respectively, show the results under air temperatures of \(-3\)\({}^{\circ}\)C, \(-5\)\({}^{\circ}\)C, \(-7\)\({}^{\circ}\)C, \(-10\)\({}^{\circ}\)C, \(-15\)\({}^{\circ}\)C and \(-20\)\({}^{\circ}\)C.  
Figure 12: Variation in the icing onset time vs. the salt concentration and air temperature: (**a–c**), respectively, show the results under wind speeds of 2 m/s, 4 m/s, and 6 m/s. solution decreases, meaning that the pavement surface temperature must drop further to reach freezing conditions. This results in a lower surface temperature and a delayed onset of icing. To further elucidate this effect, as the concentration of salt increases, the corresponding freezing point decreases. Under uniform environmental temperatures, surfaces with lower salt concentrations begin to freeze. This freezing process involves heat absorption, which slows the rate of temperature decline on the surface. Conversely, at higher salt concentrations, the lower freezing point prevents the onset of freezing, resulting in no heat absorption. Consequently, the surface temperature continues to decrease at a faster rate. This mechanism explains why surfaces treated with higher concentrations of salt exhibit more rapid cooling under the same environmental conditions, as they are less likely to reach the conditions necessary for icing to initiate. However, the experiment also indicates that under higher wind speed conditions, the effectiveness of deicing salt may be compromised. This may occur because an increased wind speed can lead to an uneven distribution of the salt solution on the pavement surface. It may be challenging to directly study the impact of the wind speed as a variable, but similar studies have found that although the transport of salt by wind is minimal, in exposed areas, an increased wind speed can hinder the distribution of salt solution, thereby affecting its effectiveness in preventing ice formation [23]. Additionally, under extreme low-temperature conditions, while deicing salt can significantly delay the onset of icing, its effectiveness is somewhat diminished in higher wind speed scenarios. This observation aligns with findings by [PERSON] et al. [24], who developed a road surface freezing model based on the heat, water, and salt balance, which was validated through field experiments. Their study found that the distribution and dissolution rate of salt solutions on road surfaces significantly influence the icing process, particularly in situations where vehicle traffic causes the dispersion of the solution. These findings underscore the importance of considering the complex interactions between environmental conditions and deicing salt concentrations when developing deicing strategies for airport pavements. Selecting an appropriate deicing salt concentration based on real-time weather conditions, such as the wind speed and air temperature, can maximize the effectiveness of deicing efforts and ensure the safety and operational efficiency of airport pavements.