IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 16, Issue 3 Ser. I (May. - June. 2019), PP 24-29 www.iosrjournals.org DOI: 10.9790/1684-1603012429 www.iosrjournals.org 24 | Page Effect of Xanthan Gum on Shear Strength Parameters of Laterite Soil in Konkan Region Aditi Sawant 1 , Anagha Patil 1 , Rushikesh Thonge 1 , Vaishnav Trankatwar 1 , Shailendra Banne 2 1 (Student, Department of Civil Engineering, Pimpri Chinchawad College of Engineering, Pune-411044, Maharashtra, India) 2 (Assistant Professor, Department of Civil Engineering, Pimpri Chinchawad College of Engineering, Pune- 411044, Maharashtra, India) Corresponding Author: Aditi Sawant 1 Abstract: Laterite formation is noticed about 70.7% in Konkan region. When laterite soil comes in contact with water it loses its strength. Use of biopolymers instead of other chemical compounds for soil treatment will develop a sustainable geotechnical system. The current study illustrates the potential of Xanthan gum polymer stabilized laterite soil. Xanthan gum in proportion 1%, 2% and 3% by mass is used for stabilization. For DST conducted on samples, cohesion increased by 35% and angle of internal friction decreased by 20% as we varied the xanthan gum content from 0% to 3%. The significant change in shear strength properties were observed for curing period of 3 days. The direct shear test was conducted using four different normal stresses of 0.5, 1, 1.5 and 2 kgcm 2 . Keywords: Biopolymer, Direct shear test, Laterite Soil, Shear strength, Xanthan gum (XG) --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 01-05-2019 Date of acceptance: 15-05-2019 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Konkan region is covered by Laterite and Deccan trap. Ratnagiri and Sindhudurga district in Maharashtra consists of Laterite soil. Laterite formation occupies about 70% of the Konkan Region. During excavations in laterite soil, due to the lithomargic clay, engineering problems like instability of slopes, landslides, cavity formation in tunneling, foundation settlement can occur. Due to the heavy rainfall in Konkan region, water seeps through this pores of laterite soil, which has the tendency to gush out leading to engineering problems, safety problems and delays in project. Hence laterite soils in tropical regions often require some soil improvement be performed in order to use it in various civil engineering applications, such as soil stabilization. The laterite soil behaves as a hard material during dry season but when it comes in contact with water, it loses its strength and behaves like a liquid. It is a combination of hydrated iron and aluminum oxides with some impurities. Laterite soil is formed by sedimentation action of parent rock, „Laterite‟ (sedimentary rock). One of the most commonly utilized stabilization techniques for laterite soils is the application of additives that chemically react with the minerals present in soil to enhance its overall strength, effective soil stabilization can consequently result in significant cost savings for a given project. Several materials like cement and cementitious materials, polymers are used for soil strengthening. But the studies showed that, CO 2 emission from usage of cementitious material is harmful to the environment. Hence, to strengthen the soil in environmental friendly manner, biopolymers can be used. Biopolymers are the polymers produced by living organisms such as algae, fungus and bacteria. Among various types of biopolymers, xanthan gum is widely used due to its good strengthening efficiency and economic feasibility based on massive commercialization. The most advantageous characteristic of Xanthan gum is its 'pseudo-plasticity'. Under static conditions, a small amount of xanthan gum induces a large increase in viscosity of any liquid. Xanthan gum displays relatively high stability over a broad range of temperature and pHs. Its anionic and hydrophilic surface characteristics react with cations and various polysaccharides resulting in gel formation stabilizes and binds the soil. Use of biopolymers instead of cementitious materials or other chemical compounds for soil treatment or improvement will develop a sustainable geotechnical system and is also an important step towards reducing the emission of harmful gases leading to global warming.