STABILIZATION OF BLACK COTTON SOIL WITH SAND AND CEMENT AS A SUBGRADE PAVEMENT

Transcription

1 International Journal of Civil Engineering and Technology (IJCIET) Volume 7, Issue 2, March-April 216, pp , Article ID: IJCIET_7_2_3 Available online at Journal Impact Factor (216): (Calculated by GISI) ISSN Print: and ISSN Online: IAEME Publication STABILIZATION OF BLACK COTTON SOIL WITH SAND AND CEMENT AS A SUBGRADE PAVEMENT V. Ramesh Babu Asst. Professor, Department of Civil Engineering, K.S.R.M.College of Engineering, Kadapa, AP K. Niveditha Asst. Professor, Department of Civil Engineering, K.S.R.M.College of Engineering, Kadapa, AP Dr. B. Ramesh Babu Principal, Ananthalakshi College of Engineering, Anantapur, AP ABSTRACT The present work is done in stabilizing the black cotton soil by using cement and sand. the tests conducted for this work were atterberg limits, specific gravity, standard proctor test, unconfined compression test, California bearing ratio. All construction should rest on the soil. So, the soil bearing capacity plays a vital role in constructions. All soils will not have good strength and bearing capacity. So there is a need to increase the soil strength and bearing capacity. The black cotton soils pose many problems in construction. So in this present work, the black soil collected from chintakommadinne mandal has been stabilized by using sand and cement. The present work aims at determines the optimum percentage of sand and cement addition to the black cotton soil in improving the strength characteristics of the soil. Key words: Unified soil classification system (USCS), CBR and Ordinary Portland cement (OPC) Cite this Article: V. Ramesh Babu, K. Niveditha and Dr. B. Ramesh Babu. Stabilization of Black Cotton Soil with Sand and Cement as A Subgrade Pavement, International Journal of Civil Engineering and Technology, 7(2), 216, pp

2 V. Ramesh Babu, K. Niveditha and Dr. B. Ramesh Babu 1. INTRODUCTION Soil is defined as sediments or other accumulation of mineral particles produced by the physical (or) chemical disintegration of rocks plus the air, water, organic matter and other substances that may be included. Soil is typically a non homogenous, porous, earthen material whose engineering behavior is influenced by changes on moisture content and density. Based on the origin, soil can be broadly classified as organic and inorganic. Organic soils are mixture derived from growth and decay of plant life and also accumulation of skeleton or shell of small organism. Inorganic soils are derived from the mechanical (or) chemical weathering of rocks. Inorganic soil that is still located at the place where it was formed is referred to residual soil. If the soil has been moved to another location by gravity, water or wind, it is referred as transported soil. Soil may remain at the place of its origin (or) it may be transported by various natural agencies. It is said to be 'residual' in the earlier situation and 'transported' in the latter. The clumping of the soil textural components of sand, silt and clay forms aggregates and the further association of those aggregates into larger unit s forms soil structure called peds. Major deposits of India The soil deposits of India can be broadly classifies into the following: Red soils, Laterite soils, Alluvial soils, Desert soils, Saline and Alkaline soils, Peaty and marshy soils and Black cotton soils. 2. LITERATURE REVIEW Mrs. Neetu B.ramteke, Prof. Anilkumar saxena, Prof. T.R.Arora (214) (9) did theirwork on the stabilization of black cotton soil with sand and cement as sub grade for pavement thus stabilization with cement is fairly independent of soil properties. The improvement of strength and compressibility characteristics of soil. The soil is then stabilized with sand and cement. The amount of sand for stabilization is taken in the proportion of 1%, 2%, 3%, and 4% by dry weight of soil and the amount of cement was taken as 2% by dry weight of soil. Using these proportions, mix samples were prepared as given below and a set of laboratory tests were performed to determine the index properties and CBR values of both natural soil and mixed proportion samples. Conducting sieve analysis test the soil is classified as: By AASHTO Classification Chart, it lies under the range of A-7 group, A- 7-5 subgroup. And by Unified soil classification system (USCS) and IS Classification system the soil is classified as MH (Silt of High Compressibility). The Atterberg limits are a basic measure of the nature of fine grained soil. Depending upon the water content of the soil, it may appear in four states namely Soild, Semi solid, Plastic, Liquid. In each state the consistency and behavior of the soil is different and thus so are its engineering properties. Thus, the boundary between each state can be defined based on a change in the soil s behavior. To assess the amount of compaction and the water content required in the field, compaction tests are done on the soil samples in the laboratory.. The study reveals that the CBR value increases with the increase in sand content and reaches to a desirable CBR value for sub grade of pavement. Normally soaked CBR value is considered for pavement design. Experimentally it is found that the addition of sand content in the soil results in the improvement of soaked CBR value from 1.93% to 7.39%. The maximum CBR is obtained while using 4% sand and 2% cement with 342

3 Stabilization of Black Cotton Soil with Sand and Cement as A Subgrade Pavement the natural soil. Atterberg limits i.e. Liquid limit, plastic limit, plasticity index and free swelling index goes on decreasing with the increase in sand content, whereas moisture content goes on decreasing and maximum dry density increases with increasing sand content. The black cotton soil after stabilizing with sand and cement for higher MDD & CBR. 3. BLACK COTTON SOILS In India, expansive soils are called as Black Cotton soil. The name Black Cotton soil has an agricultural origin. Most of these soils are black in colour and are good for growing Cotton and occurring in Maharashtra, Gujarat, Madhya Pradesh, Karnataka, Parts of Andhra Pradesh and Tamilnadu. These are expansive in nature. On account of high swelling and shrinkage potential these are difficult soils to deal with in foundation design. All the black soils are not expansive soils and all the expansive soils are not black in colour. These soils passed high strength in summer and decreased rapidly in winter. The soil has a swelling property due to the presence of montmorillonite mineral. Blackcotton soils which has high expansive characteristics. These soils are low shrinkage limit and with high optimum moisture content. It is highly sensitive to moisture changes. 4. MATERIALS AND METHODOLOGY In the present study, the following materials are used 1. Expansive soils 2. Sand and Cement 4.1. Expansive soils Type of soil used in this investigation is of having high clay content, Black cotton soil. The soil was air dried pulverized and passing through IS: 424 micron sieve was taken for the study of properties. Different Engineering properties are soil initially can be find by conducting corresponding the experiments according to IS code specification Sand and Cement Sand and cement is used and in which minimum % of cement with maximum % of sand is added to black cotton soils. By utilizing this zero costing material for the purpose of stabilization, we are in one way getting the strength of soil by using this material. This soil is stabilized with the sand and cement. The cement is ordinary Portland cement and the sand is passing through 425microns and retained on pan Methodology In this work, the black cotton soil is stabilized with sand and cement, black cotton soil is extracted from chintakommadinne area and different engineering and index properties were studied to suggest the optimum percentage of sand and cement to stabilize the expansive soil. Sand is added 1 % and cement is added 2 % up to 3 % to the expansive soil at 1 % intervals

4 V. Ramesh Babu, K. Niveditha and Dr. B. Ramesh Babu The following are the different properties studied. 1. Specific gravity 2. Free swell index 3. Liquid limit 4. Plastic limit 5. Shrinkage limit 6. Standard proctor test 7. Unconfined compression test Specific gravity (IS: 272 (part II) 198) The specific gravity of solid is defined as the ratio of the mass of a given volume of solids to the mass of an equal amount of water. Specific gravity can be determined using a density bottle. Test is conducted as per IS: 272 (part II) 198. Oven dried sample of 2 gm passing 4.75 mm IS Sieve is poured into bottle and weighed (W 3). The bottle is emptied and filled with distilled water completely and weighed (W 4). Specific gravity is determined by the following formula: G = (W 2 -W 1 )/[(W 2 - W 1 ) - (W 3 -W 4 )] Where G is the specific gravity Figure 1 Specific gravity bottle 5. REMEDIAL MEASURES The following section presents the some of the remedial measures for strengthening the weak soils Stabilization Stabilization aims at improving soil strength and increasing resistance to softening by water through bonding the soil particles together water proofing the particles. Usually, the technology provides an alternative provision structural solution to a practical problem. The simplest stabilization processes are compaction and drainage (if water drains out of wet soil it becomes stronger). The other process is by improving gradation of particle size and further improvement can be achieved by adding binders to the weak soils. All these methods fall into two broad categories: Mechanical stabilization Chemical stabilization 344

5 Stabilization of Black Cotton Soil with Sand and Cement as A Subgrade Pavement 5.2. Stabilizing agents These are hydraulic (Primary binders) or non-hydraulic (Secondary binders) materials that when in contact with water or in the presence of pozzolanic minerals reacts with water to form Cementations composite materials. The commonly used binders are: 1. Cement 2. Lime 3. Fly ash 4. Blast furnace slag 6. SAND AND CEMENT 6.1. Ordinary Portland cement Ordinary Portland cement (OPC) is the most important type of cement. The OPC was classified into three grades, namely 33 grade, 43 grade and 53 grade depending upon the strength of the cement at 28 days when tested as per IS If the 28 days strength is not less than 33N/mm 2, it is called 33 grade cement, if the strength is not less than 43N/mm 2, it is called 43 grade cement, and if the strength is not less then 53 N/mm 2, it is called 53 grade cement. It has been possible to upgrade the qualities of cement by using high quality limestone, modern equipments, closer on line control of constituents, maintaining better particle size distribution, finer grinding and better packing. Generally use of high grade cements offer many advantages for making stronger concrete. Although they are little costlier than low grade cement, they offer 1-2% savings in cement consumption and also they offer many other hidden benefits. One of the most important benefits is the faster rate of development Cross Section of Multicompartment Silos for storing different types of cement. In the modern construction activities, higher grade cements have become so popular that 33grade cement is almost out of the market. The manufacture of OPC is decreasing all over the world in view of the popularity of blended cement on account of lower energy consumption, environmental pollution, economic and other technical reasons. In advanced western countries the use of OPC has come down to about 4 per cent of the total cements production. In India for the year out of the total cement production i.e., 79 million tons, the production of OPC in 57. million tons i.e., 7%. The production of PPC is 16 million tons i.e., 19% and slag cement is 8 million tons i.e., 1%. In the years to come the use of OPC may still come down, but all the same the OPC will remain as an important type for general construction. Sand can be occurred from river beds and these are costly now days. 7. RESULTS & ANALYSIS Table 1 SPECIFIC GRAVITY (%) SL.NO DESCRIPTION Weight of density bottle W 1 in gms Weight of density bottle+ dry soil W 2 in gms Weight of density bottle+ soil+ water W 3 in gms Weight of density bottle+ water W 4 in gms Temperature of water T in c 29⁰ 29⁰ 6 Specific gravity of soil solids G

6 DRY DENSITY(ϒ d )g/cc V. Ramesh Babu, K. Niveditha and Dr. B. Ramesh Babu RESULT The average specific gravity of soil particles for density bottle method is 2.42 Table 2 STANDARD PROCTOR TEST (%) SL.NO DESCRIPTION Weight of mould Weight of mould +wet soil Weight of wet soil Container no Weight of container Weight o container + wet soil Weight of container + dry soil Weight of water Weight of dry soil Water content Wet density Dry density SPT (%) water content (%) Figure 2 SPT Analysis RESULT Optimum moisture content (OMC) = 11.8 % Maximum dry density (MDD) = 1.94 g/cc 346

7 PENETRATION (mm) Stabilization of Black Cotton Soil with Sand and Cement as A Subgrade Pavement Table 3 CALIFORNIA BEARING RATIO TEST (%) S. No Penetration dial reading Penetration in mm Proving ring dial readings in divisions Load in kg CBR(%) LOAD IN kg RESULT CBR of the given sample = 38.92mm Figure 3 CBR Analysis 347

8 water content Water content (%) V. Ramesh Babu, K. Niveditha and Dr. B. Ramesh Babu Table 4 LIQUID LIMIT 3% SL.NO DESCRIPTION Container no Weight of container No.of blows Weight of container + wet soil Weight of container + dry soil Weight of water Weight of dry soil Water content Chart Title no of blows Series1 RESULT Liquid limit of soil (LL) = 43% COMPARISON GRAPHS Chart Title LL - 1% LL - 2% LL - 3% no of blows Figure 3 LIQUID LIMIT 348

9 STRESS (kg/cm2) DRY DENSITY (g/cc) Stabilization of Black Cotton Soil with Sand and Cement as A Subgrade Pavement % 2% 3% WATER CONTENT (%) Figure 4 STANDARD PROCTOR TEST UCC - 1% UCC - 2% UCC - 3% STRAIN Figure 5 UNCONFINED COMPRESSION TEST 349

10 LOAD(KG) V. Ramesh Babu, K. Niveditha and Dr. B. Ramesh Babu CBR 1% CBR - 2% CBR - 3% PENETRATION(MM) Figure 6 CALIFORNIA BEARING RATIO TEST 8. CONCLUSIONS Black cotton soils were tested with sand and cement to ascertain the benefits of stabilization. Minimum quantity of cement i.e., 2% and sand i.e., 1% was added to target soils from 1% to 3% at 1% intervals. The tests conducted were: mechanical properties, Atterberg limits, Proctor compaction, UCC and CBR. The following trends are observed from the results of the experimental investigation: Specific Gravity: of the stabilized soil increased, in general, with increase in fly ash content. Decrease must be takes place. Liquid Limit: of stabilized soil definitely decreased with increase in sand and cement. However, there should be increase or decrease is marginal when increase in sand and cement in black cotton soils. Plastic Limit: of the stabilized soil decreased with increase in sand and cement content. However, the percentage decrease in plastic limit, at 2% sand and cement, is not related directly to the initial plastic limit of the soils. Proctor Density: There is a decrease in OMC and increase in MDD when addition of sand and cement for about 3%. Unconfined compressive strength: However, there is an gradual increase in 2% for unconfined compressive strength and decrease in 3%. There is an decrease in shear strength in 2% and increase in 3%. California Bearing Ratio: There is an decrease of CBR value for 2% and increase value for 3% 35

11 Stabilization of Black Cotton Soil with Sand and Cement as A Subgrade Pavement REFERENCES [1] K.R.Arora (1987) Soil Mechanics and Foundation Engineering, Standard Publishing Distributors. Page No: [2] BOWLES, Engineering properties of soil and their measurement. [3] TERZAGHI, Theoretical soil mechanics page No: 267 [4] IS 272: Part 16: 1987 Methods of Test for soil - part 16: Laboratory determination of CBR. [5] IS 272: Part 6: 1972 Methods of Test for soils - part 6: Determination of Shrinkage factors. [6] IS 272: Part XL: 1977 Methods of tests for soils - Part -XL: Determination of Free swell index of soils. [7] IS Part -17, Determination of water cement - Dry density relation using Light Compaction. [8] Determination of Liquid limit and Plastic limit. Indian Standard Methods for testing of soils - IS 272( a ) Indian Standard Institution New delhi, India, Part 5, pp , [9] Brijesh Kumar and Nitish Puri. Stabilization of Weak Pavement Subgrades Using Cement Kiln Dust, International Journal of Civil Engineering and Technology, 4(1), 213, pp [1] Umar Rashid Lone, Mohd Hanief Dar and Mohd Younus Ahanger. Effect of L/B Ratio of Stone Column on Bearing Capacity and Relative Settlement of Sandy Soil (An Experimental Study), International Journal of Civil Engineering and Technology, 6(1), 215, pp [11] Ahmed Neamah Naji, Dr. V. C. Agarwal, Prabhat Kumar Sinha and Mohammed Fadhil Obaid. Influence of Crude Oil Fouling on Geotechnical Properties of Clayey and Sandy Soils, International Journal of Civil Engineering and Technology, 5(3), 214, pp [12] Stabilization of black cotton soil with sand and cement as a sub grade for pavement Mrs. Neetu B. Ramteke, (june214), impact factor: