Effect of Kaolinite Clay and Different Sand Gradation Mixture on Compaction Parameters

Abstract

In nature, various types of soils are distributed in such a way that they are found together. It is very much difficult to find clay, sand, silt, gravel in a pure condition. Also, these soils (clay, sand, silt, gravel) have different geotechnical properties. Although various researchers have focused on effect of clay particles on various geotechnical properties of sand–clay mixture. But, sand is available in different size and gradations. So, the effect of sand gradation and various particle size on geotechnical properties of sand–clay mixture is still not clear or very less information available about that. In this study, effort have been made to understand the effect of clay particles (kaolinite) on compaction parameters (OMC, MDD) of various sizes and gradation of sand. Experimental work involves the preparation of six samples of sand (i.e., three poorly or uniformly graded and three well graded) from procured materials. Poorly graded samples were obtained by following sand size: coarse sand (>2 mm), medium sand (>0.425 mm and <2 mm), fine sand (<0.425 mm). For preparation of well-graded samples, efforts had been made by combining two or three types of sands, i.e., coarse, medium, and fine (C + M, M + F, C + M + F). Kaolinite clay was used as cohesive fine fraction. Different amounts of kaolin clay were added in each of the sample, i.e., 0, 5, 10, and 15%. Preliminary tests were performed on all the three well graded, three poorly graded as well as on kaolinite clay in pure condition for finding out the physical properties of the soils. (i.e., Atterberg’s limits, grain size distribution, specific gravity). Relative density test was performed for finding out the density of all the sand samples at 0% kaolin content ant 70% relative value was adopted. For all other sand–kaolin mixture (5, 10, 15%) standard proctor tests were carried out. Results indicated that among all the samples (coarse + medium + fine + 15% kaolin) exhibits greater maximum dry density (MDD) and lesser optimum moisture content (OMC) while (fine + 5%kaolinite) has lesser maximum dry density and greater optimum moisture content. So, from the results we can say for (C + M + F + 15%) sample all the particles are well arranged so the gap between the particles are minimum so the MDD of the sample goes to increase.