In the experiment, a heat-reflective coating (HRC) was applied to the surface of asphalt pavement. The coating temperature reduction principle and the mechanism to mitigate the urban heat island effect (UHI) were explored by analyzing the material characteristics and features of atmospheric absorption spectrum. HRC features a good waterproof ability, strong oil resistance, abrasion resistance, and aging resistance. When it was painted on the surface of the dense-graded asphalt concrete, the pavement temperature could be reduced by approximately 9°C in hot seasons. The comprehensive pavement performance was evaluated through the following tests: antiskid, accelerated abrasion, freeze-thaw cycle, and permeability. The results show the asphalt concrete pavement with adopting HRC has a strong abrasion resistance, a good resistance to temperature fluctuation, and significantly reduces water damage. The skid-resistant ceramic granular should be added in the dense-graded asphalt pavement with HRC, which was shown to greatly improve the antiskid capability.

This paper mainly concentrates on the thermal conductivity and photo-thermal conversion performance of polyethylene glycol (PEG)/graphene nanoplatelets (GNPs) composite phase change materials (PCMs). The temperature-assisted solution blending method is used to prepare PCM with different mass fraction of GNPs. According to the scanning electron microscope (SEM), GNPs are evenly distributed in the PEG matrix, forming a thermal conduction pathway. The Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD) results show that the composites can still inherit the crystallization structure of PEG, moreover, there are only physical reactions between PEG and GNPs rather than chemical reactions. Differential scanning calorimeter (DSC) and thermal conductivity analysis results indicate that it may be beneficial to add a low loading ration of GNPs to obtain the suitable latent heat as well as enhance the thermal conductivity of composites. To investigate the change in the rheological behavior due to the effect of GNPs, the viscosity of the composites was measured as well. The photo-thermal energy conversion experiment indicates that the PEG/GNPs composites show better performance in photothermal energy conversion, moreover, the Ultraviolet-visible-Near Infrared spectroscopy is applied to illustrate the reasons for the higher absorption efficiency of PEG/GNPs for solar irradiation.