Bcs is confined to the semiarid regions of tropical and temperate climatic zones. The black color in black cotton soil is due to the presence of titanium oxide in a little concentration. For expansive type of soil 1 black cotton soil is one of the major regional soil deposits in india, covering an area of about 3. Similarly for other proportions same procedure was followed.
The soil contracts due to its clay minerals and the structure of the clay allowing water to be imbedded inbetween the clay layers process is reversible, and causes contraction of the soil black cotton soils properties. This behaviour is attributed to the presence of a clay mineral called as montmorillonite. Light sandy soils low clay content shallow low nutrient exchange capacity entisols. Black cotton soils are generally reddish brown to black in color and occur from 0. It is well known that interlayer of clay minerals, such as montmorillonite and vermiculite, are fixed with specific cations such as potassium 8. A study on stabilization of black cotton soil and red soil. Black cotton soil is a heavy clayey soil, varying from clay to loam. The swelling property gives rise to serious problems in civil engineering on condition that it was used directly for construction. Black soil also known as regur or black cotton soil. Black cotton soils are inorganic clay of medium to high compressibility and form a major soil group of india. The sharing strength of the soil is extremely low, is highly.
Further, it is also known that magnesium ions in the exchangeable complex of the swelling minerals. The soils used in the study are dark grey clay soil classified as a76 in the aashto soil classification system, aashto 1 and cl in the united soil classification system, astm 3 2. They are found in many parts of the world, such kind of soil generally consists of active clay minerals. Swell and shrink behaviour of black cotton soils can be reduced considerably by replacing expansive soil black cotton soil with nonexpansive material. Properties black cotton soil color black specific gravity 2. Pdf black cotton soil modification by the application of. Among the in situ soils of india, the black soils found in the lavacovered areas are the most conspicuous. It is highly sensitive to moisture changes, compressible subgrade material. Black soils are derivatives of trap lava and are spread mostly across interior gujarat. Black cotton soils for the study were derived from indrasagar rockfill dam, polavaram, andhra pradesh india from a depth of 1m, 1.
Role of mineralogical composition in the activity of. They contain essentially the clay mineral montmorillonite, which is the most unstable clay mineral, thus the soils have high shrinkage and swelling characteristics. In india, about 20% of the soil cover is comprises of expansive soils also commonly known as black cotton soil. Black cotton soil modification using sea salt ejge paper styles. Studying the behaviour of the black cotton soil, cement, flyash, and metakaolin were mixed with different percentage by dry weight of soil such as 10%, 20% and 30% and the test were conducted for the different mix proportions to find the optimum values. Swelling suppression of black cotton soil by means of. Most of the area in the central region covered with the black cotton soil. Tropical black cotton clay soil tropical black cotton clay soils were collected along the dikwagamboru rd, borno state, nigeria. If the soil has been moved to another location by gravity, water or wind, it is referred to as transported soil.
The generally observed characteristics of black cotton soils are recorded in table below table 1. Effective utilization of sugar industry waste bagasse ash. What is the difference between black cotton soil and clay. Black cotton soils are worldwide problems that possess several challenges for civil engineers. The swellingshrinkage behavior changed with moisture gives rise to serious problem in civil engineering. A vertisol, or vertosol, is a soil type in which there is a high content of expansive clay minerals, many of them known as montmorillonite, that form deep cracks in drier seasons or years. Expansive soils are problematic soils because of their inherent potential to undergo volume changes corresponding to changes in the moisture regime. Black cotton soil consists of clay minerals like montmorrilonite, illite and kaolinite, chemicals like iron oxide and calcium carbonate in the form of kankars, and organic matter like humus. Pdf geotechnical investigation of black cotton soils. If the free swell index is lower than 100, the soil may be treated as nonexpansive. Vadakkunatham lime kankar quarry lease rcl quarry leasev of.
Analysis of strength characteristics of black cotton soil. Contains high percentage of montmorillonite has high swelling and shrinkage potential has very low bearing capacity formed from chemical weathering of basalt loam. C soils are also varying in their clay content and activity from region to. On the black cotton soils of north cameroon sciencedirect. Black cotton soil is very favorable for the cultivation of cotton. The main objective of the study is to characterize the black cotton soil of the area from. Black cotton soils are highly clay soil grayish to blackish in color. The name is derived from the fact that cotton grows well in the black soil. Clay minerals are made of colloidal particles having diameters less than one micron. It expands during rainy season due to presence of water and shrinks during summer season. They are abundant in regions where the annual evaporation is more than the precipitation 8. Effect of mineral additives on the behavior of an expansive soil for. Expansive soils generally called as black cotton soils covers nearly twenty percent of the geographical area in india. Black cotton soils are highly clayey soils, grayish to blackish in colour found in several states in india.
Black earths, black cotton soils, dark cracking soils, grumusols and regurs in other classification systems dudal 1965. Production of fired clay bricks and pozzolana from expansive soil. It is essential to known the clay soil and its significance related to engineering applications. Pdf comparative study on stabilized black cotton soil. Black clay soils or tropical black earth or black cotton soils are known to be. Classification of soil for engineering purpose civil.
Pdf black cotton soil modification by the application of waste. Expansive soils subjected to volume change when it comes in contact with water. Vertisols are mineral soils that have a mesic, isomesic or warmer soil. Bcs is a type of clay with high swelling potential when exposed to water 1.
Definition the definition of a vertisol varies with the classification systems used, but for convenience we have used the one adopted in india u. The black colour in black cotton soil is due to the presence of titanium oxide in small concentration. It is highly water absorbent and has high shrinkage and swelling characteristics. Black cotton soil extracted from khadakwasala pune, maharashtra state of india. Clay mineral adsorbed layer crystal face octahedral layer black cotton soil these keywords were added by machine and not by the authors. The soils are generally rich in montmorillonites and beidellite group of clay minerals. Black cotton soil properties, chemical composition, and. Clay soil is composed of very small fine particles and not much organic in nature. The black cotton soils contain the montmorillonite as a clay mineral, which causes the swelling nature in soil, due to water bond between the particles of soil.
Stabilization of black cotton soil using waste fishing net. Montmorrilonite is the predominant mineral of black cotton soils. It is a highly plastic clay, resulting from the decomposition of volcanic ash. The minerals in the clay fractions of a black cotton soil and a red. After scraping the top overburdened soil at a depth of one meter, then the sample collected. Aug 17, 2020 black cotton soils are potentially expansive soils that is they easily undergoes swelling and shrinkage due to seasonal volumetric changes. The black cotton soils contain the montmorillonite as a clay. Principally such soils contain montomorollite as main clay mineral and they exhibit high swelling and shrinkage with the seasonal moisture fluctuations. In the present study the black cotton soil was collected from belagavi region of karnataka state, and the initial tests on the black cotton soil was conducted to understand the geotechnical properties of the soil and studied for the improvement in engineering properties. The geology and geotechnical properties of the black. The swelling and shrinkage behavior of black cotton soil originate mainly from this mineral.
Ijermce vol 3, issue 5, may 2018 a study on manufacturing. A study on engineering behavior of black cotton soil and. Investigation of the effect of wpa and mdp 0,2,4,6 and 8% by dry weight of soil on the index and the strength properties of the black cotton soil stabilized with cement 0,2,4,6, and 8% by dry weight of the. Table 41 ranges of cation exchange capacities of various clay minerals. Artificial neural networks prediction of compaction. The figure below shows the weight of black cotton soil weighed for determination of liquid limit. Compaction characteristics studies of black cotton soil with. This, plus the high clay content, appears to be the main reason. The mixture of nacl solution and black cotton soil is mixed with sieved red soil in different proportion as described below. The swelling and shrinkage behavior of black cotton soil originate mainly from.
Tropical black cotton clay soils were collected along the dikwagamboru rd, borno state, nigeria. Augmenting the properties of black cotton soil using additives. Jan 25, 2020 the clay mineral that are dominant in most black cotton soil is seems to be montmorillonite. It is called black cotton soil because it is black in color formed by the presence of titaniferous magnetite. Based on classification tests, three samples were selected for mineralogical analysis. Expansive soils containing high clay content are susceptible to unfavorable volumetric changes. If the free swell index of a soil is more than 100, the soil may be expansive. Black cotton soils bcs are expansive soils which are so named due to their mostly dark color and suitability for growing cotton. Improvement of stabilization characteristics of black cotton. Principally such soils contain montomorollite as main clay mineral and they exhibit. The mineral compositions of the clays from a red earth and a black cotton soil from hyderabad, deccan state, india, occurring in close proximity in the field are. They contain montmorillonite clay mineral which has high expensive.
Effect of lignosulfonate on compaction and strength. This expansive nature is due to the presence of montmorillonite which is the predominant clay mineral in. Differential thermal analysis and xray diffraction pattern analysis have shown that montmorillonite mineral is predominant in expansive soil 1. Thered soil contained predominantly kaolin, whereas the black. Swelling suppression of black cotton soil by means of liquid. The best soil for cotton the cotton favorite, sandy loam, is silt and clay that contains some sand. Presence of montmorillonite clay minerals is mainly responsible for swelling and shrinkage characteristic of black cotton soil. Determine the physical and natural properties of the black cotton soil. Pdf stabilisation of black cotton soil using sawdust. The maximum dry density and optimum moisture content of black cotton soil. Black cotton soil was first pulverized and then dried in the oven to conduct a sieve analysis as per is 2720 part iv 1985. Introduction black cotton soil bcs is a type of highly expansive soils that are widely discovered in tropical areas, e. Statement of the problem black cotton soils are tropical expansive clay. Fired hollow clay bricks manufactured from black cotton soils.
Compaction characteristics studies of black cotton soil. It has a very low bearing capacity and high swelling and shrinkage properties. Those soils are often referred to as regur but are popularly known as black cotton soils, since cotton has been the most common traditional crop in areas where they are found. The locally available black cotton soil due to its high shrinkage and swelling characteristics is selected in the present study. Jun 15, 2017 black cotton soil bcs is mostly found in midafrica, southasia, and parts of china. Expansive soils are commonly found in arid and semi aired regions.
Clay mineralogy the dominant clay mineral in most, of the vertisols appears to be montmorillonite. Dec 01, 1975 during detailed geotechnical prospecting in north cameroon, extensive black cotton soil deposits were encountered. Mechanized opencast mining, without drilling and blasting, with deployment of heavy earth moving machineries of low hp will be adopted. The geology and geotechnical properties of the black cotton soils of. The amount of potential volume change is dependent on the mineralogical composition. Black cotton soil containing a high percentage of montmorillonite and colloidal material. Swelling properties of expansive soils treated with chemicals. It is a residual soil containing a high percentage of the clay mineral montmorillonite. Variation of plastic limit with increase in temperature plastic limit of black cotton soil is decreased from 24 to non plastic, for red soil 42 to 16 with the increase in temperature from100c to 400c. A study on stabilization of black cotton soil and red soil by. Lime was weighed using weighing balance and was mixed with black cotton soil. Black cotton soil shrink and swell with decrease and increase in water content respectively. Pdf expansive soil modification using sea salt researchgate. Various studies have tried stabilising black cotton soil by using lime, cement, flyash, and rice husk etc34567.
Experimental investigation of expansive soil on stabilization. The black cotton soil has a percentage of clay which is predominantly montmorillonite structures and black or blackish grey in colour. The surface modification of clay minerals has attracted much attention because the clay composite exhibits special characters suitable for many applications he et. Chemical analyses of clay subfractions for one black cotton soil p7 and one red earth p8, as percentages of ovendry clays black soil 121, 8 in.
In a phenomenon known as argillipedoturbation, alternate shrinking and swelling causes selfploughing, where the soil material consistently mixes itself. Improvement of stabilization characteristics of black. The swelling and shrinkage behavior of black cotton soils originate mainly from this mineral. The clay minerals are important in construction where they are constituents in brick and timajor les. The black cotton soils have been formed from basalt or trap and contain the clay mineral montmorillonate, which is responsible for the excessive swelling and shrinkage characteristics of soil. Montmorinolite is a predominant mineral of black cotton soil. However, any structure constructed on clayey soil is a troublesome. Black cotton soil is the indian name given to the expansive soil deposit in the central part of the country. Clay minerals are hydra silicate of aluminium and magnesium. Physical and chemical properties of vertisols and their. Expansive soils owe their characteristics to the presence of swelling clay minerals. This process is experimental and the keywords may be updated as the learning algorithm improves.
The clay mineral that are dominant in most black cotton soil is seems to be montmorillonite. Medium clay content dark or brown medium depth vertisols black cotton soil. Reserves of 80,90,087 tonnes lime kankar and 61,77,685 tonnes clay black cotton soil. This type of soils is mainly composed of clay minerals of smectite group which are highly expansive as exposure to water.
Clay minerals are almost ubiquitous in soil and rock and are among the most reactive silicates. Swelling properties of expansive soils treated with. The average depth of over burden black cotton soil is 1. In a phenomenon known as argillipedoturbation, alternate shrinking and swelling causes selfploughing, where the soil material consistently mixes itself, causing some vertisols to have an extremely deep a. A study on engineering behavior of black cotton soil and its. They contain montmorillonite clay mineral which has high expensive characteristics.
The soils used in the study are dark grey clay soils classified as a76 in the aashto soil classification system aashto 1986 and cl in the united soil classification system astm 1992. Bc soils have low shrinkage limit and high optimum moisture content. Volume change occurs with change in the moisture content of soil. The results indicated that the predominant clay mineral was the halloysite governing the geotechnical properties and behaviour of the cotton soils. All the clay minerals are crystalline hydrous which have lattice structure in which the atoms are arranged in several layers, this determines the type of clay mineral. Clay mineralogy of black cotton soil civil engineering world. Determine the properties of the admixture of wpa and mdp. High clay content deep one to several meters high water holding capacity high nutrient exchange capacity swell and shrink properties. The soils used in the study are dark grey clay soils classified as a76 in the aashto soil classification system aashto 1986 and cl in the united soil. Morin 1971 defined black cotton soil as dark grey to black soil which has high clay content usually over 50% and are potentially expansive. Limits, 100 grams of black cotton soil sample was weighed passing 425 micron sieve. Pdf stabilization of black cotton soil using pili and lime. This paper gives a clear idea about clay minerals and their significance.
Drastic changes observed in black cotton soil from 300c to 400c. Soil properties, soil fertility management and plant. The presence of montmorillonite in clay mineral of black cotton soil and high clay content are considered main reason of very high waterattracting or holding property of these soils. The maximum dry density and optimum moisture content of black cotton soil is 14.
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