Optimizing thermal stability in permafrost regions: A comprehensive evaluation of encapsulated phase change material enhanced energy storage embankments

Abstract

The melting of permafrost can cause serious damage to road structures. This study prepares a phase change geotextile (PCG) with heat absorption and waterproofing properties and proposes a new type of cooling structure called a phase change energy storage embankment (PCESE). A finite element model of the road is established to quantify the artificial permafrost table (APT), mean annual ground temperature (MAGT) at the bottom of the embankment, and mean daily cooling rate (MDCR) of the asphalt pavement surface under different PCESE structures. This study focuses on exploring the effects of the type of epoxy resin composite phase change material (ERPCM), dosage of ERPCM, and position of the PCG on various indices. The Entropy-TOPSIS method is used to evaluate the comprehensive performance of the PCESE and determine the optimal structure and optimization strategy. The results demonstrate that the addition of PCG to an embankment always improves the APT and MDCR, but does not necessarily reduce the MAGT. The optimal type of ERPCM, dosage of ERPCM, and position of PCG are ERPCM2, 12 kg/m2, and 3.0 m, respectively. The dosage of the ERPCM had the highest positive correlation with comprehensive performance. Considering the distribution of comprehensive performance and coefficient of variation under different structures, the recommended type of ERPCM, dosage of ERPCM, and position of the PCG are ERPCM1, 12 kg/m2, and 2.5 m, respectively.