Water Retention Characteristics of Non-plastic Granular Materials

Abstract

This paper presents experimentally determined water retention curve (WRC) for glass beads. Due to its usefulness in the determination of other unsaturated properties of particulate media, WRC has become pivotal to the implementation of the mechanics of unsaturated soil and other particulate materials. In the work reported herein tests were carried out on spherical glass beads using a pressure plate. Digital microscopic images were also taken at different matric suctions to observe water bridges between the particles as the sample dried out. Results indicate a marked difference, called the hysteresis, between the primary drying and wetting paths of the water retention curve. Within the pendular bridges zone, however, the hysteresis disappeared. It is also shown that as matric suction increases water menisci and distribution of water changes.