THE USE OF FALL CONE SLOPE IN ESTIMATION OF CLAY CONTENT
Description
The active and inactive clay content are delineated at a clay index of zero. The soil with a positive clay index is active clay, while the soil with a negative clay index is inactive clay. The soil with a positive clay index (active clay) is correlated to the liquid limit and plasticity index. In contrast, soil with a negative clay index (inactive clay) is not correlated with the liquid limit and plasticity index. This paper presents a model that predicts the clay content based on the correlation between the clay content of the soil with a positive clay index and the average fall cone slope (20/LL). The model was meticulously developed after analyzing 307 Atterberg limits and clay content test results collected from thirteen different literature. The proposed model was found to compute the clay content with an accuracy of 87% (87% of the calculated clay content results were within the statistical testing bound of ±12% given in AASHTO T88-10), ensuring its robustness.