Some relationships between shrink-swell index, liquid limit, plasticity index, activity and free swell index

Many laboratory experimental methods have been proposed to measure soil reactivity, some methods leading to direct measurement whilst other methods propose indirect estimations. Reactivity measurements based on plasticity properties appear to be commonly used and preferred over many other methods in the identification of soil expansivity, which may be due to the simplicity and easiness of test procedure. In this study, volume change potentials of several clay soil samples, containing different percentages of montmorillonite clay, are evaluated using shrink-swell index (Iss), indirect estimations based on liquid limit (LL), plasticity index (PI), activity (A) and a new approach based on free swell index (FSI). The analysis of test results presented in this paper shows that FSI could be a satisfactory indicator for the classification of the volume change potential of clayey soils.