Drying, Wetting, and Suction Characteristic Curves of a Bentonite-Sand Mixture

Abstract

The objective of the paper is to compare drying, wetting, and suction characteristic curves of a bentonite-sand mixture. A mixture, of 50 percent bentonite and 50 percent sand was prepared and used in this investigation. The main drying curve of the mixture was determined for a slurried specimen of the mixture using a chilled-mirror hygrometer. Several drying and wetting tests were also performed on the compacted mixture with an initial water content of about 9 percent and initial dry density of about 2 Mg/m3 incorporating different suction paths using a desiccator and a pressure plate apparatus. The suction characteristic curve for the mixture was obtained at loose as well as compacted states by utilizing the chilled-mirror hygrometer. The experimental results obtained are presented and compared. The drying, wetting, and suction characteristic curves of the material are different. Factors causing the differences including suction paths, hysteresis, and fabric effects are also discussed in this paper.