Investigation of the effects of anisotropic pores on material properties of insulating concrete using computed tomography and probabilistic methods

Concrete is a random heterogeneous materials and its properties are affected by the spatial distribution of its constituents. In particular, insulating concrete, a material designed for reducing heat conduction, contains numerous voids within the material, and these voids strongly affect the physical properties of the material, such as thermal conductivity and strength. The thermal insulation property of the material is enhanced as the void ratio increases, while the strength of the material decreases as void ratio increases. In this study, the effect of anisotropic pores on the material properties of insulating concrete is investigated to overcome this contradiction. A concrete specimen with anisotropic artificial pores is utilized in order to examine the effect of anisotropic pores on the material properties. The spatial distribution of pores within the specimen is visualized using X-ray tomography (CT) and quantitatively characterized using probabilistic description methods. The thermal and mechanical properties of the specimens are also examined by means of experiments and numerical simulations. The results show that an appropriate arrangement of anisotropic pores for a specific direction can be utilized for the reduction of thermal conductivity by minimizing the loss of material strength, and it can be a promising approach for developing more advanced insulating material.