Application of Phase Change Materials for Thermal Stabilization of Soils in Cold Regions

With increasing climate change, the sustainability of geotechnical infrastructure in cold regions has become a global issue. Phase Change Material (mPCM) absorbs and releases energy in the form of latent heat under varying ambient temperatures. Hence, mPCM is an alternative to stabilizing the temperature regime of an embankment, and it improves the mechanical performance of soils under freezethaw cycles. This paper aims to investigate the effectiveness of using PCM as a thermal controller in stabilizing the temperature regime of an embankment. Soils in seasonally frozen and degrading permafrost regions were selected in this study. Firstly, the soil temperature in these two regions was analyzed. After that, a comparative analysis of the effectiveness of various mPCM's was performed based on the thermogram of the differential scanning calorimetry test. At last, a PCM-soil model was developed to simulate the thermophysical properties of reinforced soil mixture in both regions. The results show that mPCM was the most effective in soil temperature control during its phase transition. The maximum temperature rise in the mPCM soil layer was 1.4 degrees C under seasonal freezing conditions. With the presence of mPCM, a decrease in the maximum seasonal freezing rate and depth was observed. Under permafrost conditions, the application of mPCM at a depth of 1.2 m led to the reduction of soil temperature by 1.2 degrees C. This study demonstrates the thermoregulatory effects of mPCM on the reduction of the embankment's temperature and therefore by the application of mPCM the degradation of permafrost is prevented.