A probabilistic approach for the assessment of the influence of the dielectric constant of pore fluids on the liquid limit of smectite and kaolinite

Liquid limit (LL) is defined as a limiting water content separating the viscous liquid state and plastic state of soil consistency. LL of clays, being a basic physico-chemical property, plays a role in environmental geotechnical engineering practice. Since it is well-known that kaolinite and smectite behave quite differently from each other from the geotechnical point of view, ninety-one data regarding smectite (Na and Ca) and kaolinite mixed with organic pore fluids having different dielectric constant (ε) values have been carefully analyzed. Data confirm that for a decreasing ε value of the pore fluid a decrease in LL is observed for the smectitic clays, with different magnitude depending on the main ion, whereas for kaolinitic clays this decreasing ε causes an increase in attractive forces causing flocculation and increase in LL values. A probabilistic approach has been performed to assess the robustness of the regression functions. For smectitic and kaolinitic clays the mathematical dependency of LL with ε is validated by the probabilistic analysis.