Influence of fabric variables on clay-water-air capillary meniscus

The mechanical behavior of unsaturated clays is strongly governed by capillary water and the resulting capillary forces. In this paper, the influence of fabric variables on the air-water capillary meniscus between clay particles is studied using molecular dynamics. Considering a system of two clay particles, the fabric variables studied are the angle between particles, edge-to-face separation, clay-water contact length, and particle thickness. The molecular dynamic results are analyzed to determine the contact angle and radius of curvature of the meniscus. It is found that the values of the contact angle fall within a narrow range for the fabric variables considered. The radius of curvature varies with the spacing and angle, but is derivable from knowledge of the contact angle.