Influence of soil structure and clay mineralogy on Atterberg limits

Plasticity properties of fine-grained soils in the form of Atterberg limits are very important inferential properties used for classification and preliminary qualitative assessment of their suitability for any geotechnical engineering applications. Through extensive research, it is well understood that clay mineralogy and soil structure are the main factors that control the Atterberg limits of soils. To further the understanding of the factors influencing the Atterberg limit of soils at the macro level with an insight at the micro level through SEM studies, the present study was taken up using various soil mixtures prepared with extreme clay minerals (Bentonite and Kaolinite), fine sand, and silt (extracted from a natural soil). From the experimental results reported herein, the changes observed in the Atterberg limits as influenced by the variation in the composition of the fractions in the clay-sand-silt mixture may be due to the influence of clay mineral type and the clay structure which are supported by the SEM images.