GTU Design Engineering Report on Sustainable Soil Stabilization
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GUJARAT TECHNOLOGICAL UNIVERSITY
Chandkheda , Ahmedabad
Affiliated
GOVERNMENT ENGINEERING
COLLEGE,
VALSAD
A
Project Report
On
SUSTAINABLE STABILIZATION OF SOIL
Under Subject Of
DESIGN ENGINEERING – II – A
B.E.III, Semester – V
(Civil Branch)
Submitted By:
Group:
Sr. Name of Student Enrollment No.
1 Patel Aditya Harnishbhai 190190106029
2 Patel Bhavin Rajendrabhai 190190106033
3 Patel Digant Pratapkumar 190190106036
4 Prajapati Savan Shambhubhai 190190106060
Prof. Priyanka S Patel
(Faculty Guide)
Prof. D J Patel
(Head of the Department)
Academic Year
(2021-22)
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INDEX
Sr. Title Page No.
1 Introduction – Sustainable Stabilization of Soil 3
2 Soil Stabilization 4
3 Stabilizing Using Polyurethane 5
4 Stabilizing Using Cement 8
5 Stabilizing Uising Bitumen 9
6 Stabilizing Using Lime 10
7 Canvas 11
8 Conclusion 18
9 Reference 18
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INTRODUCTION :
Soil Stabilization is defined as chemical or physical treatments
which increase or maintain the stability of soil or improve its engineering
properties.
The main purpose of soil stabilization is substituting poor grade
soils with aggregate processing more favourable engineering properties. It
is also promote the use of waste geomaterials in construction. It is enhancing
the properties of soil on site. It gives the strength and bearing capacity of the
soil. It is also useful in waterproofing for conservation of natural or
manmade structures.
Mechanical stabilazion, Chemical stabilization and biological
stabilization are the methods of soil stabilization. The method of stabilizing
soils is a commonly undertaken procedure in the construction of airfields,
parking lots, landfills, embankments, roads and foundations, waterway
management, agriculture and mining sites. The type of stabilization that
might be used depend upon the site; it may use a single method or a
combination of the two.
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SOIL STABILIZATION
WHAT IS SOIL STABILIZATION ?
Soil stabilization is a technique to refine and improve the engineering
properties of soils. These properties include mechanical strength,
permeability, compressibility, durability and plasticity. Physical or
mechanical improvement is common but some schools of thought prefer to
use the term ‘stabilization’ in reference to chemical improvements in the soil
properties by adding chemical admixtures.
WHAT IS THE SOIL STABILIZATION PROCESS ?
Understand the material properties involved in the mixture and the
intended outcome after mixing.
Evaluate the effects of the process on the nearby structures and
surrounding conditions.
Consider factors such as mixing and spreading, selection of roller,
compaction, layer thickness.
Choose the sequence of operation
If working with chemicals evaluate curing, environmental and climatic
conditions.
WHAT ARE THE MATERIALS USED IN SOIL STABILIZATION ?
Different grades of soil.
Different grades of aggregates
Seedlings
Geomaterials – geogrids, geoblankets
Polymers -synthetic and natural
Cement
Lime
Fly ash
Bitumen
Recycled and waste products – solid municipal, mining and industrial
wastes.
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STABILIZING USING POLYURETHANE
POLYURETHANE AS A GROUTING MATERIAL
The broad category of polyurethane chemical grout has a number of
applications to rock mechanics and civil engineering as a whole due to the
wide range of strengths and chemical properties that are available. Because
of the wide range of polyurethanes available, it is clear from the literature
that there is some ambiguity in naming convention of these different types
of Polyurethane products, which generally causes confusion. Most research
recognizes and separates polyurethane grouts based on their chemical and
physical properties, however the names each category are given become
interchanged amongst various sources.
The efficiency of the polyurethane foam as a stabilizing agent for the
pavement subbase layer and foundation systems concerned with relative
movement and excessive settlement problems has been confirmed in many
experimental and in-situ studies.
ADVANTAGE OF POLYURETHANE
POLYURETHANE has a number of advantages over other types of grouting
materials. It has a low viscosity, allowing it to penetrate small fractures. In
addition, the material itself can reach strengths that are 3 to 4 times those
reached by cementitious grouts.
Perhaps the biggest advantage of Polyurethane over other types of grouting
materials is the control over the properties of the material. Through
chemistry of the Polyurethane mixture alone, viscosity, set time, strength,
and expansion properties can be controlled at a much higher resolution
than other types of grouting materials.
DISADVANTAGE OF POLYURETHANE
Polyurethane products are typically harder to pump than less viscous
cementitious grouts Additionally, with water, Polyurethane products may
foam and expel through open fractures on a rock face, requiring quick
cleanup of the overrun material, before it hardens and removal becomes a
more difficult task. Also, Polyurethane is typically higher in cost than other
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types of cementitious grouts. For this reason, Polyurethane is sometimes
used in conjunction with other types of stabilization to lower project costs.
Polyurethane can be cost effective for a project provided a good
characterization of the rock mass is performed and material is not wasted
on poor field implementation.
GEOTEXTILE AS A STABILIZER
Geotextiles are made from porous synthetic materials such as polyethylene,
polyester, nylons, and polyvinyl chloride. There is a different variety of
geotextiles available like woven, non-woven, and grid. Geotextiles materials
generally have high strength.
When geotextile is properly combined and embedded in the soil which will
contribute to its stability. This type of soil stabilization method is generally
used for the construction of unpaved roads over soft soils. Reinforcing the
soil by geotextile materials or metallic strips and providing an anchor or tie
back to restrain a facing skin element.
These materials can improve the quality and durability of future highways
and may reduce the cost of construction. At present, lots of research and
studies are going on these materials based on tests conducted in the
laboratory that are only partially complete. Detailed study and practical
research are essential for the future use of geotextile materials.
ADVANTAGES OF GEOTEXTILE
a) Cost – saving material
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b) Increase construction speed
c) Achieves supplementing
d) Improve quality
PLASTIC WASTE AS A SOIL STABILIZER
There are lots of waste materials in the world and proper disposal of such
waste materials as crushed old asphalt pavement, copper and zinc slag,
paper mill sludge, and rubber tire chips are essential to developing proper
and effective Soil Stabilization method.
There is a service need to recycle hazardous materials, it will be necessary
to develop a realistic, economical, and effective means of assessing the risk
of pollution posed by these materials through leachates and emissions.
Plastics are one of the leading waste materials that are found to be suitable
for this purpose. They reduce the cost of stabilization at a large rate. Using
plastics for this purpose simultaneously solves the challenges of improper
plastic waste recycling that is currently a teething problem in most
developing countries. Polyethylene Terephthalate (PET) bottles are
conventional plastic bottles that currently are highly utilized. They are used
to package water, soft drinks, liquid foods, and various other beverages.
With their increasing demand, their disposal is becoming difficult. The
degradation of waste PET bottles takes a very long time in nature (more
than a hundred years).
Recycling and using these plastic bottles to stabilize expansive clay soil are
moves in the right direction making the construction industry an
appropriate candidate with its high consumption ability. This will be a
decent alternative for clearing and protecting the environment from waste
plastic bottles.
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STABILIZING USING CEMENT
Soil cements stabilization, in which soil particles are bonded together by
the cement hydration process which grows into crystals that can interlock
with one another giving a high compressive strength. To achieve a hard and
strong bond between soil particles cement particles need to coat most of
the material particles.
To assure good contact between cement and soil particles for proper bond
and efficient soil stabilization, cement particles must be well mixed with
certain particle size particles of soil. Soil cement is generally known as a
highly compact mixture of soil, cement, and water.
Soil – cement bond material is hard and durable material as the cement
hydrates and develops strength. Cement stabilization is mostly employed
when the compaction process is continuing. When cement is added to the
soil is fills the void between the soil particles, the void ratio of soil is
reduced.
As cement and soil particles mixed well the water is added to the soil,
cement reacts with water and goes hard. So, the unit weight of the soil is
increased. As cement in the soil get harder the shear strength and bearing
capacity are also increased. Cement in stabilized soil decreases the liquid
limit and increases the plasticity index and workability of clayey soils.
It is fact that Cement chemical reactions are not dependent on soil
minerals, and the key role is its reaction with water that may be available in
any soil. This is the primary reason that cement is mostly used to stabilize
soil of any type.
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STABILIZING USING BITUMEN
The bituminous soil stabilization method is the method in which is a
suitable amount of bituminous material is added and mixed in soil or
aggregate material to produce a stable base or wearing surface. Bituminous
materials in the soil increase the cohesion and load-bearing capacity of the
soil and render it resistant to the action of water.
Bitumen stabilization of soil is generally done by using asphalt cement,
asphalt cutback, or asphalt emulsions.
The types of bitumen to be used for stabilization is generally dependent on
the type of soil to be stabilized, method of construction, and weather
conditions. Tar binders in frost are must be avoided because of their high-
temperature maximum susceptibility.
Asphalts and tars are mostly used in pavement construction as bituminous
materials. Bituminous materials when added to soil improves soil cohesion
and reduced water absorption.
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STABILIZING USING LIME
Lime stabilization is one of the cheapest soil stabilization methods.
The soil stabilization method in which lime is added to the soil to improve
its properties is known as lime stabilization. There are different types of
lime used like hydrated high calcium lime, monohydrated dolomite lime,
calcite quick lime, dolomite lime. The amount of lime generally added in
most soil stabilizers is in the range of 5% to 10%.
Lime Soil stabilization method improvement properties show by increase
in strength brought by cation exchange capacity rather than the cementing
effect brought by the pozzolanic reaction.
Lime stabilization also indicated by the pozzolanic reaction in which
pozzolana materials react with lime in presence of water to produce
cementitious compounds. The effect created is indicated by either
quicklime, CaO, or hydrated lime, Ca(OH)2.
Lime stabilizations method is most widely utilized in geotechnical and
environmental applications.
It has some important applications like an encapsulation of contaminants,
highway, slope stabilization, rendering of backfill, and foundation
improvement.
However, any existence of sulphur and organic materials may inhibit the
lime stabilization process. Sulphate (e.g. gypsum) generally reacts with
lime and swell, which may have an effect on soil strength.
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CONCLUSION
This study is conducted with the objective to develop quality control
measure in soil stabilization and review the stabilizer selection criteria. Soil
stabilization should be well promoted among the professionals in industry
as a solution for the problem scarcity of soil with good quality. The
promotion should be done through improving their knowledge and loyalty
on stabilization technology.
REFERENCE
Soil Mechanics & Foundation , By B.C.Punmia
https://theconstructor.org/geotechnical/soil-stabilization-methods-
and-materials/9439/
https://www.ciconstructors.com/soil-stabilization-strong-
foundations-for-big-projects/
https://www.scirp.org/journal/paperinformation.aspx?paperid=989
76
https://youtu.be/gBJdrn0T1MI