1 Influence of nano-materials on compaction and strength behaviour of clayey soils B. A. Mir & S. Hariprasad Reddy Department of Civil Engineering, National Institute of Technology, Srinagar-190006, J&K, India ABSTRACT Soil being particulate system, encompasses a wide variety of particles, which has made it one of the most complicated natural materials to be modeled. Among soils, soft soil deposits pose challenging problems to geotechnical engineers for the assessment of reliable behaviour of these soils to be used either as a foundation medium or construction material. In this study, Nano-Material additives have been chosen to investigate their influence on strength behavior of clayey soil. Two soil samples are treated with Nano-material additives of Nano- copper (CuO) and Nano-Gypsum (CaSO4·2H2O) at varying percentages of 0.5%, 1.0%, 1.5% and 2.0% respectively. The test results revealed that the unconfined compressive strength of soil increased significantly with increasing Nano-Material additives. However, the optimum value of Nano-Material additives content was observed around 1.5%. Therefore, the main goal of this study was to stabilize soft soil deposits for its bulk utilization in various geotechnical applications for sustainable environment. 1 INTRODUCTION The Nanotechnologies idea was first suggested by Richard Feynman in 1959 (Feynman 1959). After that, this technology developed in all branch of sciences. Research and technology development at the atomic, molecular or macromolecular levels, at a length scale of approximately 1-100nm (NNI 2007). There are so many methods of soil stabilization used today like Mechanical, cement, Chemical and additives. In that, Nano materials is one of the newest additives being used in the geotechnical engineering field. Soft soil deposits are usually weak with a very low bearing capacity and even undergo excessive settlement that takes place over along period of time (Mir et al. 2015; Mir et al. 2016). In recent years Nanotechnology is also getting popularity in the field of Civil engineering and Geotechnical engineering. In particular methods, there are two basic methods of defining particle size. First method is to assay the particles and make actual measurements of their dimensions. Microscopic techniques, for example, measure many dimensional parameters from particle images (Abhishek arya et al 2017). Second method is utilizing the relationship among particle behaviour and its volume. This frequently suggest an assumption of equivalent spherical size developed using a size-dependent property of the particle and relating it to a linear dimension. In this research, scanning electron microscopy (SEM) have been used to characterize the particle size of Nano- copper (CuO) and Nano-Gypsum (CasO4.2H2O). (Arabania et al. 2012) In this study Investigated results of Unconfined compressive strength (UCS) and California Bearing Ratio (CBR) of sand cement mixtures are contain varies percentage of Nano-clay. The results showed that the reaction of alumina-silicate elements in nano-clay calcium hydroxide in cement increased bond strength and consequently giving in higher tensile strength of hardened cement paste. Due to the addition of Nano-clay, the structure of soil cement mixture has become denser and even very small voids have been expelled. (Firoozi et al. 2014) In this present study, performed on a clayey soil sample mixed with Nano-Zeolite of different percentages (0.0, 0.1, 0.3, 0.5, 0.7, 1.0, 2.0, and 3.0%). The consistency limits tests showed that the consistency limits vary with addition of different percentages of Nano-Zeolite. (priyadharshini et al. 2015) Conducted an experimental research on "Improvement of Bearing capacity of soft clay using nano materials" In this research nano material's (i.e., Nano clay, Nano-Magnesium oxide and Nano-Alumina) are added at different percentages to the soft clay. with the increase in the different percentages of Nano clay and Nano-Alumina, the optimum moisture content increase and maximum dry density decrease. similarly, with increase in Nano-Magnesium oxide vice versa. This study involves assessment of the geotechnical properties of clayey soils treated with nano materials as the sumptuous nature of soil gets decrease on addition of Nano-Silica and Nano-Zeolite. It is examined the consistency limits increase with increase of Nano-Silica. On addition of Nano-Zeolite decreases the consistency limits with the increase in the different percentages of Nano-Silica and Nano-Zeolite, the optimum moisture content increase and dry density gets decreases. The shear strength parameters of soils are improved on the addition of varying percentages of Nano-Silica and Nano-Zeolite (Hareesh et al. 2016). This study carried out investigation on the basic geotechnical properties of admixtures of natural soils. SEM analysis showed that more nano sized particles were obtained after the process. Consistency limits and specific surface area were checked and after addition of