Entransy dissipation thermal resistance for asphalt pavement and application in optimization of cooling structure

Asphalt pavement cooling can alleviate urban heat island effect and promote sustainable urbanization. However, the current design of cooling pavement cannot meet the needs of efficient cooling due to the lack of optimization index. The goal of this study is to make the optimization design of cooling pavement more scientific by applying the entransy dissipation theory. The entransy balance equation of pavement was established. Then taking the gradient heat conduction pavement as the research object, the cooling mechanism was analyzed by using the entransy dissipation thermal resistance (R_g). Finally, according to the cooling mechanism, the optimized pavement was established with R_g as the optimization index, and the temperature and thermal effect of pavement before and after optimization were evaluated. The results indicated that resistance exists in the heat transfer process, which was defined as R_g. Gradient heat conduction pavement could realize cooling by increasing the R_g. The R_g of gradient heat conduction pavement was 1.30 times that of ordinary pavement. However, the temperature could only be reduced by 0.6 °C compared with that of the ordinary pavement. On the contrary, the optimized pavement could lower the temperature by 3.8 °C compared with that of the ordinary pavement, and the heat dissipation and absorption were 24.42% higher and 15.08% lower than those of the gradient heat conduction pavement. The cooling effect of optimized pavement was verified by an indoor irradiation test. In conclusion, the optimized pavement can be built with a good cooling effect by using R_g as optimization index.