Dynamic investigation of mass transfer in freezing soil with computer tomograph

With X-ray scanning through the sample of freezing soil section by section, we can obtain the data reflecting the changing of water content and density of each section without destruction. We have done several tests on freezing clay with initial water content 22.40%. The heights and diameters of samples are 6cm and 10cm respectively. The temperature is -2.7C on top and +0.75C at bottom. The tests run for 14 hours in closed system. We scanned the sample at different time section by section. The data reflect the dynamic changing or redistribution of water content and density. Combined with the relationship between frost heave amount and elapsed time, the change of water content and density in each section with elapsed time has been determined. The results are significant for dynamic study of mass transfer, ice formation, cryotexture development and mechanism of frost heave in freezing soil.