Improvement in CBR Characteristics of Red Mud using Single Geogrid Layer Tanmaya Kumar Sahoo Postgraduate Student, Department of Civil Engineering National Institute of Technology Jamshedpur Jamshedpur,India Dr. Anil Kumar Choudhary Associate Professor, Department of Civil Engineering National Institute of Technology Jamshedpur Jamshedpur,India Abstract— In India millions of tons of red mud are produced from alumina industries. Its property is similar to sandy clay and it mainly comprises of oxides of aluminum, iron and silicon. Its storage has created enormous problems. To solve this problem alternate uses of red mud should be investigated. Improvement of load bearing characteristics of red mud with the help of geogrid is presented in this paper. This reinforced red mud will be useful as pavement materials for roads, particularly in areas nearer to alumina industries. This paper presents laboratory test, particularly soaked California Bearing Ratio test conducted on unreinforced and red mud reinforced with single geogrid layer. CBR test results are compared for reinforced red mud by varying the embedment depth of geogrid layer. Consequently, it is concluded that according to load bearing criteria optimum embedment depth of geogrid is equal to diameter of CBR loading plunger. Keywords— Embedment ratio, CBR, CBRI, Subgrade modulus, Pavement thickness. I.INTRODUCTION Red mud is a waste byproduct generated during the production of alumina from bauxite by the Bayer process. During the production of 1 ton of alumina 0.8 to 1.5 tons of red mud is produced (Liu and Zhang. 2011). In country like India, where land resource is scarce storage and disposal of red mud have created a great disaster. Therefore, researches are going on to find alternate uses of red mud. Literatures are available on alternate uses of red mud, like production of geopolymer(He et al. 2013; Kumar and Kumar 2013) (cement ((Singh et al. 1996; Tsakiridis et al. 2004)), brick (Kavas 2006; Yang and Xiao 2008), Red mud have also been used as a road construction material(Jianzhao 2005; Kehagia 2008) . Red mud have properties similar to clay and sand; even if it does not contains any quartz or clay minerals. Similarity in properties is may be due to presence of hydroxysodalite, goethite, and hematite in red mud. Frictional behavior of red mud is similar to sand and compression behavior similar to clay(Newson et al. 2006). Due to the similarity in properties with soil red mud can be used as substitute of soil, which can solve disposal and storage problem associated with it. In the present study attempts are made to illustrate effective use of geogrid to reinforce red mud to improve its load carrying capacity. Geogrids are reinforcing elements which is used to increase strength of soil subgrade. Polypropylene geogrids are preferred over jute geogrid for important projects because of its high strength and durability( Choudhary et al. 2012). In this experimental work, load bearing characteristics of unreinforced and reinforced red mud were studied by conducting soaked CBR tests on both type of samples. The main objective of paper is to study the effect of embedment depth of geogrid reinforcement on load carrying capacity of red mud so that red mud can be used as road construction material in areas nearer to alumina industries. To accomplish this objective soaked CBR tests on red mud reinforced by single geogrid layer having different embedment depths of 0.25d, 0.5d, 0.75d, 1.00d. 1.50d were conducted and test results are analyzed to investigate the effect of embedment depth of reinforcement on soaked CBR characteristics. II.MATERIALS Red mud taken for study had been collected from HINDALCO, Muri. Grain size distribution curve of red mud is shown in figure 1. Geogrid had collected from local market. Figure 1 Grain size distribution curve of red mud International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 www.ijert.org IJERTV4IS030100 (This work is licensed under a Creative Commons Attribution 4.0 International License.) Vol. 4 Issue 03, March-2015 1