This paper presents findings obtained by evaluating the compressive strength, thermal conductivity, and durability of sand cylinder specimens stabilized with either epoxy emulsion (EM), acrylic polymer aqueous solution (APAS), EM-APAS mixture, or EM-APAS-lime mixture. Given the data obtained from the laboratory test, simulation analysis that uses a heat transfer fluid model of a ground-coupled heat pump (GCHP) system confirms the EM-APAS-lime binder performs best in the compressive strength and thermal conductivity; EM-APAS mixture performs best in the durability. However, the slake durability index of specimens containing EM-APAS-lime is equal to or greater than 80%. In addition, the compressive strength of sand stabilized with the EM-APAS-lime mixture is more than three times that of sand stabilized with cement. The thermal conductivity of sand stabilized with cement and that of sand treated with EM-APAS-lime mixture are 0.1 W/m·K and 0.9-1 W/m·K, respectively. It is confirmed that the heat collection of sand stabilized with EM-APAS-lime outperforms five times over that of sand stabilized with cement. These findings provide admissible evidence that the EM-APAS-lime mixture, which outperforms cement in compressive strength and thermal conductivity, is most suitable for ground improvement binder for GCHP systems.
Keywords: acrylic polymer; compressive strength; epoxy emulsion; ground-coupled heat pump; heat transfer fluid model; sand stabilization; thermal conductivity.