IDENTIFICATION OF CLAY MINERALS IN THE SOIL USING ATTERBERG LIMIT PARAMETERS

Montmorillonite clay is a problematic soil for both geotechnical and pavement engineers. Therefore, identifying the presence of the expansive montmorillonite clay mineral within the soil matrix using a simple and inexpensive method is of paramount importance. This paper presents a simple method of identifying the primary clay minerals, namely kaolinite, illite, and montmorillonite, in the soil matrix using Atterberg limits parameters, namely plasticity index, plastic limit, and slope of the fall cone curve (defined as 20/LL). The proposed methods can be used as a preliminary indicator method of identifying the presence of expansive clay minerals within the soil matrix before carrying out an expensive definitive method of identifying clay minerals, such as XRD.