Regulating the albedo and radiation absorption of engineering surfaces for cooling the embankments in high-altitude permafrost regions

Abstract

Under the influences of global warming and strong solar radiation, the construction of the wide high-grade roads in high-altitude permafrost regions becomes more challenging. To reach the challenges and further improve the thermal-mechanical stabilities of the permafrost embankment, this study proposes a novel cooling embankment structure based on the heat-reflective coatings. The principle is to reduce and regulate the solar radiation absorption by the permafrost embankment surface, thus improving the temperature field of the embankment and preventing uneven settlement and other freeze-thaw damages of the embankment. First, a theoretical-empirical model is proposed to describe the transfer processes of incident radiations on the pavement and slope surfaces. Based on the model, we carry out a systematic study of the main factors influencing the solar radiation absorption of the embankment surfaces and their variation patterns. By analyzing the calculation results, we propose the regulating schemes of the heat-reflective coatings for the radiation absorption balance of the embankment surfaces. Meanwhile, the solar albedo properties of the heat-reflective coatings under different solar spectral are also studied. The results indicate that the heat-reflective coatings can significantly reduce the solar radiation absorbed by the embankment surfaces. It proves that the cooling embankment structure and albedo regulation schemes proposed in this paper are expected to be applied in practical engineering. Finally, we discuss the shortcomings of the current research and the next research plans.