International Journal of Science and Engineering Research (IJ0SER), Vol 2 Issue 7 july-2014 Shahabas banu. . . . (IJ0SER) July- 2014 Experimental Investigation Of Soil Stabilization shahabas banu.s M.E structural engineering J.C.T College Of Engineering And Technology Coimbatore, Tamilnadu,India. * Abstract— Clays exhibit generally undesirable engineering properties. They tend to have low shear strengths and to lose shear strength further upon wetting or other physical disturbances. They can be plastic and compressible and they expand when wetted and shrink when dried. Some types expand and shrink greatly upon wetting and drying – a very undesirable feature. Cohesive soils can creep over time under constant load, especially when the shear stress is approaching its shear strength, making them prone to sliding. They develop large lateral pressures. They tend to have low resilient modulus values. For these reasons, clays are generally poor materials for foundations. The annual cost of damage done to non-military engineering structures constructed on expansive soils is estimated as many billions of dollars worldwide. Many admixtures are successfully used for stabilizing expansive clays. The strength characteristics of stabilized clays are measured by means of unconfined compressive strength (UCS) or California Bearing Ratio (CBR) values. Depending upon the soil type, the effective admixtures content for improving the engineering properties of the soil is varied. Keywords— California Bearing Ratio, Cohesive soils, Proctor Compaction Test, specific gravity. I. INTRODUCTION Soil stabilization refers to the procedure in which a special soil, a cementing material, or other chemical material is added to a natural soil to improve one or more of its properties. One may achieve stabilization by mechanically mixing the natural soil and stabilizing material together so as to achieve a homogeneous mixture or by adding stabilizing material to an undisturbed soil deposit and obtaining interaction by letting it permeate through soil voids. Where the soil and stabilizing agent are blended and worked together, the placement process usually includes compaction. Soil stabilizing additives are used to improve the properties of less–desirable rood soils. When used these stabilizing agents can improve and maintain soil moisture content, increase soil particle cohesion and serve as cementing and water proofing agents. A difficult problem in civil engineering works exists when the sub-grade is found to be clay soil. Soils having high clay content have the tendency to swell when their moisture content is allowed to increase. Many research have been done on the subject of soil stabilization using various additives, the most common methods of soil stabilization of clay soils in pavement work are cement and lime stabilization. The high strengths obtained from cement and lime stabilization may not always be required, however, and there is justification for seeking cheaper additives which may be used to alter the soil properties. A. OBJECTIVE Soils are highly susceptible to volume and strength changes and hence can cause severe roughness and accelerate the detoriation of the pavement structure in the form of increased cracking and decreased ride quality, when combined with truck traffic. In some cases, the sub grade soils can be treated with various materials to improve the strength and stiffness characteristics of the soil. This thesis investigates the potential of using vegetable fiber such as coir in ground engineering applications. In order to better understand the role of reinforcing material (coir) in improving the strength sub grade pavement, an attempt is made in this present study with the following objectives. To find the most efficient way of using coir fibers to reinforce the available soil sample, since its environmental and financial advantages are considerable. Effect of change of percentage fiber content on the engineering properties of compacted soil II. REQUIREMENTS OF SOIL STABILISATION Every stabilization process will be satisfactory when it provides required qualities and fulfills the following criteria: (1) Be compactable with soil material (2) Be permanent (3) Be easily handled and processed (4) Cheap and safe
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International Journal of Science and Engineering Research (IJ0SER),
Vol 2 Issue 7 july-2014
Shahabas banu. . . . (IJ0SER) July- 2014
Experimental Investigation Of Soil Stabilization
shahabas banu.s M.E structural engineering
J.C.T College Of Engineering And Technology
Coimbatore, Tamilnadu,India.
*
Abstract— Clays exhibit generally undesirable engineering properties. They tend to have low shear strengths and to lose shear
strength further upon wetting or other physical disturbances. They can be plastic and compressible and they expand when wetted and
shrink when dried. Some types expand and shrink greatly upon wetting and drying – a very undesirable feature. Cohesive soils can
creep over time under constant load, especially when the shear stress is approaching its shear strength, making them prone to sliding.
They develop large lateral pressures. They tend to have low resilient modulus values. For these reasons, clays are generally poor
materials for foundations. The annual cost of damage done to non-military engineering structures constructed on expansive soils is
estimated as many billions of dollars worldwide. Many admixtures are successfully used for stabilizing expansive clays. The strength
characteristics of stabilized clays are measured by means of unconfined compressive strength (UCS) or California Bearing Ratio
(CBR) values. Depending upon the soil type, the effective admixtures content for improving the engineering properties of the soil is
varied.
Keywords— California Bearing Ratio, Cohesive soils, Proctor Compaction Test, specific gravity.
I. INTRODUCTION
Soil stabilization refers to the procedure in which a special
soil, a cementing material, or other chemical material is added
to a natural soil to improve one or more of its properties. One
may achieve stabilization by mechanically mixing the natural
soil and stabilizing material together so as to achieve a
homogeneous mixture or by adding stabilizing material to an
undisturbed soil deposit and obtaining interaction by letting it
permeate through soil voids. Where the soil and stabilizing
agent are blended and worked together, the placement process
usually includes compaction. Soil stabilizing additives are
used to improve the properties of less–desirable rood soils. When used these stabilizing agents can improve and maintain
soil moisture content, increase soil particle cohesion and serve
as cementing and water proofing agents.
A difficult problem in civil engineering works exists when
the sub-grade is found to be clay soil. Soils having high clay
content have the tendency to swell when their moisture
content is allowed to increase. Many research have been done
on the subject of soil stabilization using various additives, the
most common methods of soil stabilization of clay soils in pavement work are cement and lime stabilization. The high
strengths obtained from cement and lime stabilization may not
always be required, however, and there is justification for
seeking cheaper additives which may be used to alter the soil
properties.
A. OBJECTIVE
Soils are highly susceptible to volume and strength changes
and hence can cause severe roughness and accelerate the
detoriation of the pavement structure in the form of increased
cracking and decreased ride quality, when combined with
truck traffic. In some cases, the sub grade soils can be treated
with various materials to improve the strength and stiffness
characteristics of the soil.
This thesis investigates the potential of using
vegetable fiber such as coir in ground engineering
applications. In order to better understand the role of
reinforcing material (coir) in improving the strength sub grade pavement, an attempt is made in this
present study with the following objectives.
To find the most efficient way of using coir fibers to
reinforce the available soil sample, since its
environmental and financial advantages are
considerable.
Effect of change of percentage fiber content on the
engineering properties of compacted soil
II. REQUIREMENTS OF SOIL STABILISATION
Every stabilization process will be satisfactory when
it provides required qualities and fulfills the
following criteria:
(1) Be compactable with soil material
(2) Be permanent
(3) Be easily handled and processed
(4) Cheap and safe
International Journal of Science and Engineering Research (IJ0SER),
Vol 2 Issue 7 july-2014
Shahabas banu. . . . (IJ0SER) July- 2014
A. MECHANICAL STABILISATION:
Mechanical stabilization involves two operations,
(a) Changing the composition of the soil by addition or
removal of certain constituents
(b) Densification or compaction
B. CEMENT STABILISATION:
The soil stabilized with Portland cement is known as soil
cement. The cementing action is believed to be result of
chemical reaction of cement with the silicous soil during
hydration. The binding action individual particles through
cement may be possible only in coarse – grained soils. In fine grained, cohesive soils, only some of the particles have
expected to have cement bonds, and rest will be bonded
through natural cohesion.
C. LIME STABILISATION
Hydrated (or slaked) lime is very effective
in treating heavy, plastic, clayey, soils. Lime may be used
alone or in combination with cement, bitumen, or fly ash.
Sandy soils can also be stabilized with these combinations.
Lime has been mainly used for stabilizing the road bases and sub- grades.
On addition of lime to soil, two main types
of chemical reactions occur:
(a) Alteration in the nature of the absorbed
layer through base exchange phenomenon
(b) Cementing or pozzolanic action.
III. STABILIZER
The admixtures that added to the soil to improve its
engineering performance are termed as stabilizers.
A. TYPES OF STABILIZERS
The types of stabilizers used are,
Coconut Coir
Sodium Chloride (NaCl)
Rice Husk Ash
B. COCONUT COIR
Coir is a natural fiber extracted from the husk of
coconut and used in products such as floor mats, doormats,
brushes, mattresses etc. Technically coir is the fibrous
material found between the hard, internal shell and the outer
coat of a coconut. Other uses of brown coir (made from ripe coconut) are in upholstery padding, sacking and horticulture.
White coir is harvested from unripe coconuts, and is used for
making finer brushes, string, rope and fishing nets.
Total world coir fiber production is 250,000 tonne (250,000
long tons; 280,000 short tons). The coir fiber industry is
particularly important in some areas of the developing world.
India, mainly in Pollachi 40% and the coastal region of Kerala
State, produces 20% of the total world supply of white coir
fiber. Sri Lanka produces annually throughout the world of
consumed in the countries of origin, mainly India. Together
India and Sri Lanka produce 90% of the 250,000 metric tons
of coir produced every year.
C PHYSICAL PROPERTIES OF COIR:
The physical appearance and quality of the fibers varies
widely. The color of the fiber is not influenced by the species
of the nut from which it is derived but also its maturity, time
lapse between dehusking and retting etc. However under identical conditions of these variables, the fibers extracted
from infant nuts exhibit a pale yellow color. The intensity of
color and thickness increase with age and the fibers are
remarkably stiff and posses good extensibility.
Morphologically, coir is a multi cellular fiber with 12 to 24
microns in diameter and the ratio of length to thickness is
observed to be 35.
D. SODIUM CHLORIDE
The stabilizing action of chloride is somewhat to that of calcium chloride, but it has not been so widely used. It attracts
and retains moisture and reduces the rate of evaporation.
Another beneficial phenomenon is the crystallization of the
salt in the soil pores near the surface, which retards further
evaporation and also reduces the formation of shrinkage
cracks.
E. RICE HUSK ASH
Rice Husk Ash (RHA) is obtained from the
burning of rice husk. The husk is a by-product of the rice milling industry. By weight, 10% of the rice grain is rice husk.
On burning the rice husk, about 20% becomes RHA
F. CHEMICAL COMPOSITION OF RICE HUSK ASH
Silica – SiO2 90.23%
Alumina – Al2O3 2.54%
Carbon 2.23%
Calcium Oxide – CaO 1.58%
Magnesium Oxide – MgO 0.53%
Potassium Oxide – KaO 0.39%
Ferric Oxide – Fe2O3 0.21%
G. SOIL SAMPLE
The soil sample is clay soil which is distributed in most of
the places around the coast of Bay of Bengal. A disturbed soil
sample is that in which a natural structure of soil get partly or
fully modified and is destroyed although with suitable
precautions for natural moisture content may be preserved.
Such a sample is called as representative soil sample. The representative soil sample for the thesis was collected
from a construction site near Pondicherry and it was analyzed
for its strength properties. An open pit was made up to a depth
of 1.5m below the ground surface where the representative
[3] Indian Standards METHODS OF TEST FOR SOILS (Second
Revision) IS: 2720 (Part 1 to Part 41) - 1983, Indian Standards
Institution, April 1984, New Delhi.
[4] Indian Standards METHODS OF TEST FOR STABILIZED IS: 4332
(Part 2 to Part 10) - 1967, Indian Standards Institution, January 1968,
New Delhi.
[5] Indian Standards GLOSSARY OF TERMS AND SYMBOLS (First
Revision) IS: 2809 - 1972, Indian Standards Institution, September
1972, New Delhi.
[6] National Building Code.
shahabas banu She is percusing M.E structural engineering in J.C.T college of Engg. & Tech., Coimbatore. She completed her B.E.(civil) in Nehru institute of technology, Coimbatore