IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 15, Issue 4 Ver. III (Jul. - Aug. 2018), PP 41-46 www.iosrjournals.org DOI: 10.9790/1684-1504034146 www.iosrjournals.org 41 | Page A Study on Stabilization of Expansive Soil with Ground Granulated Blast Furnace Slag and Flash S. Ammireddy 1 , K.Sridevi 2 , Ch.Sivanarayana 3, Dr. D S V Prasad 4 1 (M.Tech Student, Department of Civil Engineering, BVC Engineering College, Odalarevu, AP, India) 2( Assistant Professor, Dept. of Civil Engineering, BVC Engineering College, Odalarevu, AP, India). 3( Assistant Professor, Dept. of Civil Engineering, BVC Engineering College, Odalarevu, AP, India) 4( Principal & Professor of Civil Engineering, BVC Engineering College, Odalarevu, AP, India) Corresponding Author: S. Ammireddy Abstract: Soil stabilization is one of most important for the construction which is widely used in connection with pavements and structures because it improves the engineering properties of soil. Utilization of industrial waste materials in the improvement of soils is a cost efficient and environmental friendly method. Stabilization of the expansive soil is studied by using flyash and Ground Granulated Blast Furnace. In the present investigation is to evaluate the compaction, CBR and unconfined compressive strength of stabilized black cotton soil using flyash and Ground Granulated Blast Furnace with different percentages. The geotechnical properties like compaction parameters has increased enabling increase California Bearing Ratio in both soaked and unsoaked conditions which indicates that improved in strength. From these results, it was found that optimum GGBS is 5 % and 5% flyash gives the maximum increment in the CBR and UCS values compared with all the other combinations. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 19-07-2018 Date of acceptance: 02-08-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Expansive soils popularly known as black cotton soils, because of their suitability for growing cotton, cover almost 20% of the geographical land available in India. These deposits, because of the specific physical and chemical makeup, are undergoing volume changes with seasonal variations (Snethen et al., 1975; Chen, 1988). Civil Engineers face many difficulties when construction activities are to be done in expansive soils such as Black Cotton Soil because of their unconventional behaviour. Soils, which exhibit a peculiar alternate swell- shrink behavior due to moisture fluctuations, are known as expansive soils. Stabilization is a method of processing available materials for the production of low-cost road design and construction, the emphasis is definitely placed upon the effective utilization of waste by products like flyash, GGBS with a view to decreasing the construction cost. Sharma and Sivapullaiah (2011), study the effectiveness of binder viz., Flyash or Ground Granulated Blast furnace slag (GGBS) were mixed with the expansive soil along with a small amount of lime to increase soil pH and enable pozzolanic reactions. Based on the findings, both Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) decreased with the addition of GGBS to the BC soil which isdue to predominant effects of reduced clay content and increased frictional resisting. Unconfined compressive strength (UCS) of the Flyash-GGBS mixture increases with the increase in the GGBS content. The reduction in strength in the Flyash-GGBS mixtures is overcome by addition of lime. Kiran B. Biradar et al., (2014), were studied the performance of crusher dust, flyash and steel slag mixing with different percentages blending in soil and from the results decrease in consistency limits, soil has exhibited lower void ratios with the addition of Quarry dust and Steel slag,improvement in compaction characteristics increase in maximum dry density and decrease in OMC with steel slag & quarry dust and an opposite trend with flyash. Both Unsoaked and soaked CBR has been improved with admixtures and the improvement is more pronounced in soaked performance over Unsoaked. Performance ratio improved for UCS with the addition of admixtures. 1.18, 1.27 and 1.09 times improvement is observed with addition of Quarry dust, Steel slag and flyash respectively. Dayalan (2016) studied the different amount of flyash and GGBS are mixed separately, i.e., 5%, 10%, 15% and 20% by dry weight of soil and conducted various physical and strength performance tests like specific gravity, Atterberg limits, standard proctor test and CBR tests. From the results, it was found that optimum value of flyash is 15% and GGBS is 20% for stabilization of given soil based on CBR value, and with the increases of flyash and GGBS percentage, OMC goes on decreasing while maximum dry density goes on increasing, hence compact ability of soil increases and making the soil more dense and hard. The CBR value increases with increase in amount of flyash and attained maximum value at 15%and again decreases. The same trend is also observed in GGBS in which the maximum CBR value (8.6%) is attained at 15% of GGBS. In this investigation, different