Stabilization of black cotton soil using wooden ash


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Stabilization of black cotton soil using wooden ash..civil advanced project for future..

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Stabilization of black cotton soil using wooden ash

  2. 2. Introduction  Aimed at evaluating the possibility of utilizing wooden ash in the stabilization of black cotton soils  Black cotton soils possess low strength and undergo excessive volume changes, making their use in constructions very difficult  These soils cause more extensive damage than even natural disasters  Hence, we must increase the compressive strength of black cotton soil with using of wooden ash
  3. 3. Reasons for this Study  Economic progress and growth of a country is closely dependent on the infrastructural development  Pavements of least thickness are found to be the most economical  This is possible only when the underlying soil has greater strength  Black cotton soil possesses low strength. If the soil is weak, then the thickness of the pavements increases.  So for such problematic soil, it is essential to stabilize them in the most economic and affective way.
  4. 4. Feasibility of Wooden Ash  Various research works have been undertaken for improving the expansive nature of the black cotton soil using materials like wooden ash, as admixture.  Wooden ash is a locally available material residue powder left after the combustion of wood, such as burning wooden in a home fireplace or an industrial power plant.  It is used traditionally by gardeners as a good source of potash for domestic gardens.
  5. 5. Material Source Black cotton soil has been collected from a field in Athupalam, Coimbatore Wooden ash has been collected from Malumichapetti region.
  6. 6. Laboratory tests  The following are the various laboratory tests conducted on the samples collected Specific Gravity test Dry Sieve Analysis Relative Density Test Liquid Limit Test Plastic Limit Test Standard proctor compaction Test
  7. 7. Natural Moisture Content NATURAL MOISTURE CONTENT  All moisture content determination was done by the oven drying method  For the determination of natural moisture content, samples were collected in polythene bag and immediately taken to the laboratory for the test.  The water content is calculated from equation.
  8. 8. Where m1 = mass of container (g)  m2 = mass of container and wet soil (g)  m3 = mass of container and dry soil (g) The natural moisture content was determined to be 26.95 %
  9. 9. Specific Gravity The density bottle method The specific gravity of the soil sample was done by using density bottle method. The sieved sample was grouped into approximately four equal parts. Each part was placed into dried 50cm3 density bottle of known mass (M1) to the nearest 0.01gsing
  10. 10. The mass of each bottle with sample inside was measured (M2) to the nearest 0.01g.  Each bottle was then filled with water and mixed thoroughly removing all air bubbles. The bottle was weighed to a mass (M3).
  11. 11. Finally each bottle was washed and dried. Water was introduced and the mass of the bottle with water full taken (M4). The specific gravity is expressed as : Gs = =2.941 The average of the values was taken for various samples.
  12. 12. Pychnometer
  13. 13. Particle Size Distribution  The particle size distribution of the natural soil was determined using the method specify by BS 1377 (1990) for cohesive soil. It specifies the use of both sedimentation analysis and the dry sieving of the coarse fraction
  14. 14. When the black cotton soil was treated with 2 - 12% wood ash by dry weight of soil at optimum moisture content (OMC), less than 10% of the material passed through BS No.  200 sieve, and therefore did not meet the minimum requirement for sedimentation analysis to be carried out.
  15. 15. Sieve Panals
  16. 16. Liquid Limit  200g of the air dried BC soil passing 425–μm sieve size was taken and was mixed with water and kneaded for achieving uniformity.  The mixing time was specified as 5 to 10 min. The soil paste was placed in the liquid limit cup, and leveled off with the help of the spatula.  A clean and sharp groove was cut in the middle by means of a grooving tool.  The crank was rotated at about 2 revolutions per second and the number of blows required to make the halves of the soil pat separated by the groove meet for a length of about 12 mm was counted.
  17. 17. Conclusion • From this project we observed that when admixture is added to black cotton soil (wooden ash) there is a increase in strength of soil and less change in volume of soil. • Hence its can be used economical in construction.
  18. 18. References Study of Geotechnical properties of black cotton soil Electronic Journal of Geotechnical Engineering- Characteristics of wood ash and influence on soil properties www.ncbi.nlm.nih.govpubmed Wood ash –