AIJREAS VOLUME 1, ISSUE 10 (2016, OCT) (ISSN-2455-6300) ONLINE ANVESHANA’S INTERNATIONAL JOURNAL OF RESEARCH IN ENGINEERING AND APPLIED SCIENCES SOIL STABILIZATION USING GEOPOLYMER AND BIOPOLYMER P.DILIP KUMAR RAO, M.Tech(Geotech) SRINIVAS GANTA Department of Civil Engineering Associate professor, Abhinav Hitech College of Engineering Department of Civil Engineering E-mail: [email protected] Abhinav Hitech College of Engineering E-mail: [email protected] ABSTRACT permeability, durability and dust control is improved, which makes the soil suitable As stabilization of soil improves its engineering for use. There are different methods of properties, chemical and mechanical stabilization processes are in use. In the present study two stabilization, which include physical, difficult soils; expansive soil and dispersive soil are chemical and polymer methods of stabilized with geopolymer and biopolymer. stabilization. Physical methods involve Sodium based alkaline activators and fly ash as an physical processes to improve soil additive is used as geopolymer and Xanthan gum properties. This includes compaction and Guar gum are used as biopolymers. The effectiveness of geopolymer is studied in terms of methods and drainage. Drainage is an unconfined compressive strength (UCS), efficient way to remove excessive water differential free swelling (DFS), swelling pressure from soil by means of pumps, pipes and (SP), durability and dispersion tests. The swelling canal with an aim to prevent soil from pressure got reduced by 97.14% finally with swelling due to saturation with water. addition of 40% fly ash and 15% bentonite. The dispersion test showed bentonite to be an extremely Compaction processes lead to increase in dispersive soil, whose dispersiveness is controlled water resistance capacity of soil. Drainage by addition of alkali activated fly ash. From UCS is less common due to generally poor and durability test it is observed that bentonite connection between method effectiveness added with 40% fly ash and 10% solution gave and cost. But, compaction is very common better results. The effectiveness of biopolymer is studied based on UCS tests on dispersive soil and method. Although, it makes soil more pond ash at their moisture content. For dispersive resistant to water, this resistance will be soil, durability, dispersion and DFS tests are also reducing over time. Chemical soil done. It is observed that dispersive soil and pond stabilization uses chemicals and emulsions ash mixed with various percentages of Xanthan as compaction aids, water repellents and gum and Guar gum are not dispersive and are more durable than ordinary bottom ash and binders. The most effective chemical soil dispersive soil samples. Guar gum is found to stabilization is one which results in non- imparts higher confined compressive strength and water-soluble and hard soil matrix. durability than Xanthan gum. Polymer methods of stabilization have a number of significant advantages over INTRODUCTION physical and chemical methods. These Soil stabilization in a broad sense includes polymers are cheaper and are more various methods used for modifying the effective and significantly less dangerous properties of soil to enhance its for the environment as compared to many engineering performance. By stabilization chemical solutions. In the present study the major properties of soil, i.e., volume difficult soil i.e, expansive soil is stability, strength, compressibility, ANVESHANA’S INTERNATIONAL JOURNAL OF RESEARCH IN ENGINEERING AND APPLIED SCIENCES EMAIL ID: [email protected] , WEBSITE: www.anveshanaindia.com 280 AIJREAS VOLUME 1, ISSUE 10 (2016, OCT) (ISSN-2455-6300) ONLINE ANVESHANA’S INTERNATIONAL JOURNAL OF RESEARCH IN ENGINEERING AND APPLIED SCIENCES considered for effectiveness of percentage of lime (0 to 8%) was added geopolymer and biopolymer stabilization. with the expansive soil-fly ash- desulphogypsum mixture. The treated Objective and Scope samples were cured for 7 and 28 days. The objective of the current research work Swelling percentage was found to reduced is to determine the suitability of and rate of swell was found to increase geopolymer (alkali-activated fly ash) and with increase in stabilizer percentage. biopolymer as soil stabilizing agent for Curing resulted in further reduction in expansive soil. swelling percentage. With addition of 25 Scope percent fly ash and 30 percent Laboratory investigation for desulphogypsum, the swelling percentage characterization of bentonite soil reduced to levels comparable to lime with alkali activated fly ash stabilization. (geopolymer) as binding material. Amu et al. (2005) used cement and fly ash It includes laboratory investigation mixture for stabilization of expansive for characterization of bentonite clayey soil.The expansive soil was treated soil with two commercially with (i) 12% cement and (ii) 9% cement + available biopolymers i.e., Xanthan 3% fly ash and were tested for maximum gum and Guar gum. dry densities (MDD), optimum moisture contents (OMC), California bearing ratio LITERATURE REVIEW (CBR), unconfined compressive strength (UCS) and the undrainedtriaxial tests. The Satyanarayanaet al. (2004) studied the results showed that the soil sample combined effect of addition of fly ash and stabilized with a mixture of 9% cement + lime onengineering properties of 3% fly ash is better with respect to MDD, expansive soil and found that the optimum OMC, CBR and shearing resistance proportions of soil: fly ash: lime should be compared to samples stabilized with 12% 70:30:4 for construction of roads and cement, indicated the importance of fly ash embankments. in improving the stabilizing potential of Phani Kumar and Sharma (2004) cement on expansive soil. observed that plasticity, hydraulic Kumar et al. (2007) studied the effects of conductivity andswelling properties of the polyester fibre inclusions and lime expansive soil fly ash blends decreased stabilization onthe geotechnical and the dry unit weight and strength characteristics of fly ash-expansive soil increased with increase in fly ash content. mixtures. Lime and fly ash were added The resistance to penetration of the blends with an expansive soil at ranges of 1–10% increased significantly with an increase in and 1–20%, respectively. The samples fly ash content fora given water content. with optimum proportion of fly ash and They presented a statistical model to lime content (15% fly ash and 8% lime) predict the undrained shear strength of the based on compaction, unconfined treated soil. compression and split tensile strength, Baytar (2005) studied the stabilization of were added with 0, 0.5, 1.0,1.5 and 2% expansive soils using the fly ash and plain and crimped polyester fibres by desulpho-gypsum obtained from thermal weight. The MDD of soil-fly ash-lime power plant by 0 to 30 percent. Varied mixes decreased with increase in fly ash ANVESHANA’S INTERNATIONAL JOURNAL OF RESEARCH IN ENGINEERING AND APPLIED SCIENCES EMAIL ID: [email protected] , WEBSITE: www.anveshanaindia.com 281 AIJREAS VOLUME 1, ISSUE 10 (2016, OCT) (ISSN-2455-6300) ONLINE ANVESHANA’S INTERNATIONAL JOURNAL OF RESEARCH IN ENGINEERING AND APPLIED SCIENCES and lime content. The polyester fibres Similarly, a single literature (Chen et al.) (0.5–2.0%) had no significant effect on for the use of biopolymer in stabilization MDD and OMC of fly ash-soil-lime-fibre of soil is available. So, in this present study an attempt has been made to use mixtures. However, the unconfined geopolymer as an alternative cementitious compressive strength and split tensile material in stabilizing expansive soil and strength increased with addition of fibres. biopolymers (Xanthan gum and Guar gum) Buhler and Cerato (2007) studied the are used to stabilize expansive soil. stabilization of expansive soils using lime and Class C flyash. The reduction in linear MATERIAL AND METHODOLOGY shrinkage was better with lime In the present study soil are considered namely stabilization as compared to same bentonite soil have been stabilized using percentage of Class C fly ash. geopolymers (alkali activators, sodium Stabilization using quarry dust silicate: sodium hydroxide in 2:1 ratio) and The quarry dust/ crusher dust obtained biopolymers. The alkali solution sodium during crushing of stone to obtain silicate: sodium hydroxide in 2:1 ratio was aggregates causes health hazard in the used in different concentrations. vicinity and many times considered as an In the present study, methodology of aggregate waste. Stalin et al. (2004) made an investigation stabilizing soil using geopolymer and regarding control of swelling potential biopolymer is explained as follows. (SP)of expansive clays using quarry dust Stabilization using geopolymer and marble powder and observed that liquid limit and swelling pressure In the present study, the alkali was decreased with increase in quarry dust or marble powder content. prepared by taking sodium silicate and Stabilization using biopolymer sodium hydroxide keeping in view, the Chen et al. (2013) performed a preliminary study on using Xanthan gum ratio of sodium silicate to sodium and Guargum, two hydroxide in their dry mass as 2. The biopolymers that are naturally occurring prepared alkali (S) was added in varying and inexpensive, to stabilize mine tailings (MT). The addition of these two percentages (5%, 10%and 15%) with fly biopolymers increased both liquid limit ash (FA) in different percentages (20%, and the undrained shear strength of the MT.