Soil‐Fabric Measurement using Phase Transition Porosimetry

Abstract

A new method for the study of soil fabric has been developed. This method has been referred to as conductometric phase transition porosimetry (CPTP). With CPTP, changes in electrical conductance and temperature of saturated soil samples are measured during a cycle of capillary freezing and melting. These measurements are used to calculate the sample's pore size distribution. The paper includes an introduction to CPTP, an investigation of the variability of test results, a comparison of results with mercury intrusion porosimetry (MIP), and a discussion of the advantages and disadvantages of CPTP. Experimental results show that the new methodology can provide a useful and valuable tool for quantitative studies of soil fabric and is capable of measuring pore sizes between 2.5 nm and 5,000 nm diameter. Pore sizes measured by CPTP are smaller than MIP‐measured pore sizes. Due to the lesser disturbance of pore structure and much larger sample size, CPTP provides a more accurate and representative measure of the pore structure of recompacted fine‐grained soils than MIP.