Experimental research on thermal properties of reactive powder concrete at −165 °C–20 °C

RPC has stable thermal performance in ultra-low temperature environments, with significantly lower thermal conductivity than ordinary concrete. Its thermal parameters are less affected by temperature changes, providing key data support and engineering application verification for the full concrete design of liquefied natural gas storage tanks. This article investigates the thermal properties of reactive powder concrete (RPC) in ultra-low temperature environments inside liquefied natural gas storage tanks. The study found that within the temperature range of −165 °C to 20 °C, the specific heat capacity of RPC decreases linearly with decreasing temperature, while the addition of coarse aggregates and steel fibers has little effect on it. Meanwhile, the thermal expansion coefficient of the material does not show significant changes with decreasing temperature, but the addition of coarse aggregates and steel fibers can reduce this coefficient. The thermal conductivity of RPC increases first and then decreases with the decrease of temperature, but the overall change is small, and its thermal conductivity is significantly lower than that of ordinary concrete; Coarse aggregates and steel fibers will moderately improve their thermal conductivity. Through temperature field simulation verification, the experimental test results can accurately reflect the thermal parameter characteristics of the material under actual ultra-low temperature conditions, supporting its feasibility for application in liquefied natural gas storage tank engineering.