Relation Between Rheological Properties and Dry‐state b Dimension of Various Na‐smectites

Abstract

AbstractThe liquid limits of pastes of five different Na‐smectites were determined with the conventional liquid‐limit device. In addition, the penetration rate of a Teflon cone into each paste was determined at different water contents by means of a precision penetrometer. The water content at which a curve of penetration rate versus water content showed maximal curvature was called the “critical” water content. Both the liquid limit and “critical” water content were shown to decrease as the b dimension of the Na‐smectite increased. Since recent work has shown that the specific surface area of a Na‐smectite depends on its dry‐state b dimension, plots were made of the liquid limit and critical water content against specific surface area. They showed that both indicators of consistency increased curvilinearly with specific surface area. However, at a given state of consistency, the interparticle distance was not the same in the different smectite‐water systems but depended on the b dimension. Reasons for these findings were discussed in relation to the theory of plastic flow.