Experimental study of phase change energy pile based on Gum Arabic and Polyethylene Glycol 600 under multiple Thermal-Cold cycles

Temperature fluctuations cause energy piles to experience thermomechanical responses that affect their structural stability. The current trend in innovative energy pile technology is the application of phase change concrete to mitigate adverse thermomechanical responses. The exceptional feature of this research is that phase change concrete (GPC) based on Gum Arabic (GA) and Polyethylene glycol 600 (PEG-600) was used to cast phase change energy piles (GPEP). During five thermal-cold cycles, an indoor model test compared the GPEP to a traditional energy pile (TEP). The results demonstrated that the heat exchange efficiency of GPEP was 46.8 % (thermal cycle) and 27.1 % (cold cycle) higher than that of TEP. In addition, GPEP exhibited a lower pile temperature response and temperature fluctuation than TEP. GPEP exhibited a smaller perimeter soil influence range (2.0D) than TEP. GPEP exhibited a lower additional temperature stress variation than TEP (maximum shrinkage of 50.91 %). After five thermal-cold cycles, GPEP and TEP experienced subsidence accumulation, but GPEP exhibited 77.24 % less accumulated subsidence than TEP. This study provides a reference for the practical engineering applications of GPEP.