DENSITY DISTRIBUTIONS WITHIN CERAMIC MATERIALS SATURATED FOR USE IN SUCTION MEASUREMENT

Abstract

Unsaturated soil contains air and water within the voids of the skeleton formed by soil particles.
To investigate the complicated behavior of these materials through unsaturated soil testing, pore air and water
pressure must be measured and controlled independently. For this purpose, a microporous ceramic material is
used. The ceramic, which is installed in tensiometers and other experimental apparatus used for testing
unsaturated soil, must be saturated using degassed water. The degree of saturation of the ceramic influences
the accuracy of measuring and controlling suction. However, microporous ceramic is difficult to saturate.
Currently, the ceramic material is saturated using empirical methods, the applicability of which have not been
confirmed up until now. In this study, the effects of ceramic saturation methods were investigated. Three kinds
of saturation methods, the vacuum method, the pressurization method, and the Berthelot method, were utilized.
In each method, saturation time and the number of saturation cycles was varied. The saturated ceramic was
also exposed to air drying to check the saturation effect, and X-ray computed tomography was used to visualize
the degree of saturation of the ceramic. These efforts determined that trends in the distribution of saturation
within the ceramic are dependent on saturation method.