Experimental study on the measurement of interfacial thermal contact resistance of layered porous materials

As a typical porous material, the thermal conduction characteristics of the interfaces between adjacent layers during the thermal consolidation of soil are one of the key issues that need to be considered in engineering design. Thermal contact resistance (TCR) is a core parameter for characterizing the heat transfer at the contact interface in thermal management. In order to deeply investigate the influence mechanism of TCR, this paper developed an experimental system designed for measuring the TCR of the interface of water-containing porous materials based on the steady-state heat flow method and Fourier's law of heat conduction. With saturated soil, sand and concrete as examples, the influence of various factors on the TCR of different specimen combinations are analyzed. Results show TCR exists at the interface of adjacent porous materials, causing hot-end temperature increment to rise and cold-end to fall; TCR decreases with the increase of the temperature increment gradually between saturated soil and sand; TCR is larger when the fine aggregate is manufactured sand. Moreover, both the increase in the temperature increment and the water-cement ratio will reduce the TCR gradually; Moisture content significantly influences TCR at the clay-sand interface, with significance decreasing in the order: moisture content > temperature > dry density.