STUDY OF SOIL PROPERTIES WITH SILICA FUME AS STABLIZER AND COMPARING THE SAME WITH RBI-81 AND COST...

VISVESVARAYA TECHNOLOGICAL UNIVERSITY

Belgaum-590 014

PROJECT REPORT

On

“STUDY OF SOIL PROPERTIES WITH SILICA FUME AS STABLIZER AND COMPARING THE SAME WITH RBI-81 AND COST ESTIMATION”

Submitted in partial fulfillment of the requirements for the Degree of

Post Graduate Diploma in Highway Technology

by

VENU GOPAL.N

USN: 1IR08CHT19

Under the Guidance of

Miss. G. KAVITHA

Lecturer,

RASTA – Center for Road Technology,

Bangalore.

RASTA – Center for Road Technology

VTU – Extension Center

VOLVO Construction Equipment Road Machinery Campus

1

Peenya, Bangalore – 560 058

RASTA – Center for Road Technology

VTU – Extension Center

VOLVO Construction Equipment Road Machinery Campus

Bangalore – 560 058.

CERTIFICATE

Certified that the Project work entitled “STUDY OF SOIL PROPERTIES

WITH SILICA FUME AS STABLIZER AND COMPARING THE

SAME WITH RBI-81 AND COST ESTIMATION” is a bonafied work carried

out by, Mr. VENU GOPAL.N, University Seat Number 1IR08CHT19 in partial fulfillment for the award of

M-Tech degree in Highway Technology of the Visvesvaraya Technological University, Belgaum during

the year 2008-2009. It is certified that all corrections/suggestions indicated for Internal Assessment have

been incorporated in the report. The Project report has been approved as it satisfies the academic

requirements in respect of Project work prescribed for the said Degree.

Signature of Guide Signature of Head of PG Studies

(Miss. G.Kavitha) (Dr. Krishnamurthy)

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ACKNOWLEDGEMENT

It’s indeed my immense pleasure to wish my deep sense of gratitude to our teaching faculty

who inexorably tried to get the best out of me. It is because of their valuable guidance and continuous

encouragement without which this milestone would not have been a success.

I extend my sincere thanks to Dr.Krishna Murthy, for his valuable guidance and

suggestions during the course of study.

I would like to express my sincere gratitude to Miss. G.Kavitha and Mr. Anjaneyappa faculties of

IR Rasta for excellent guidance and encouragement throughout the seminar.

Last but not the least, I also thankful to all my class mates, non-teaching staff and friends, who

have helped directly or indirectly for the successful completion of this work.

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SYNOPSIS

Soils exhibits high plasticity characteristics, low strength properties and high swell shrink

characteristics. The alternative swell- shrink seasons causes distress to the structures and the

pavements constructed on them. Maintenance and repair costs of the distressed structures and

pavements are quite high. It is, therefore, necessary either to bring suitable soils from far off

borrow areas or to stabilize locally available soils to improve their engineering properties.

In the present study, a soil sample was subjected to laboratory investigation to know the

grain size distribution pattern and to determine liquid limit, plastic limit and plasticity index,

optimum moisture content, maximum dry density and California bearing ratio values. The

laboratory investigations indicate the soil samples posses’ low strength. In order to improve the

strength of native soil, the soil samples were treated by varying Silica Fume and RBI-81 grade

content in the range of 1% to 4% by weight. The treated soil samples were subjected to triaxial

compression test to determine strength of soil.

The above obtained values such as CBR value, young’s Modulus etc were used for the

design of pavement based on IRC methods, thickness of pavement were calculated and

compared.

This involves replacing of base and sub-base course with stabilized locally available soil,

and comparing same with different stabilizer (RBI-81and Silica Fume). To evaluate the

difference in cost.

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INDEX

Topics Page No

Chapter.1 Introduction 4-6

1.1 General Studies 4

1.2 Desirable properties of soil 5

1.3 Objective of present study 6

1.4 Scope of Present Study 6

Chapter.2 Literature review 7-20


2.2 Characteristics of soil 7

2.3 Index properties 7

2.4 Determination of Soil Properties 9

2.5 Subgrade soil Strength 9

2.6 Soil Stabilization Using Inorganic stabilizer 11

2.7 Stabilized Soil with RBI-81 12

2.8 Silica Fume 15

2.9 Chemical Properties of silica fume 17

2.10 Physical properties and contribution 17

2.11 Soil Stabilization method 19

2.12 Technique of Stabilization 20

2.13 Design and Cost estimation 20

Chapter.3 Present Investigation 21-25


3.2 laboratory test conducted 22

5

Chapter.4 Analysis of Result 26-43


4.2 Laboratory test result 26

4.3 Design of Pavement 36

4.4 Materials Quantity 39

4.5 Cost Estimation 40

Chapter.5 Discussion and conclusion 44-45

5.1 Discussion 44

5.2 Conclusion 45

5.3 Scope for future studies 45

References 46

Annexure 1 47-57

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CHAPTER-1

INTRODUCTION

1.1 GENERAL

Soil - mineral matter formed by the disintegration of rocks due to action of water, frost,

temperature, pressure or by plant or animal life. Soil is the most abundantly available construction

material; the term soil has different connotations for scientists belonging to different disciplines. The

definition given to a soil by an agriculturist or a geologist is different from the one used by a civil

engineer. For a civil engineer, soils mean all naturally occurring, relatively unconsolidated earth

material- organic or inorganic in character that lies above the bed rock. Soils can be broken down into

their constituent particles relatively easily, such as by agitation in water.

Soil is the ultimate foundation material which supports the overlying structure. The proper

functioning of the above lying structure will therefore depend critically on the success of the

foundation element. Soil is the cheapest and the most widely used material in a highway system,

either in its natural form or in a processed form. All road pavement structures eventually rest on

soil foundation. However, soil is highly heterogeneous and anisotropic in nature and occurs in

unlimited varieties, with widely different engineering properties. Considering all these aspects, a

through study of the engineering properties of soil is of vital importance in working out an

appropriate design of the pavement structure which will yield an acceptable level of performance

of the road over the design life under the given traffic and climatic conditions. In any road

embankment, the bulk of the material used is soil and if properly designed, should possess stable

slopes and should not settle to any appreciable extent. Also, the embankments require a stable

foundation; if the foundation soil happens to be soft clay, unless properly designed; excessive

settlement or even ultimate failure can take place.

In developing countries like India the biggest handicap to provide a complete net work of road

system is the limited finances available to build road by the conventional methods. Therefore there is a

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need to resort to one of the suitable methods of low cost road construction to meet the growing needs of

the road traffic. The construction cost can be considerably decreased by selecting local materials

including local soils for the construction of the lower layers of the pavement such as the sub-base

course. If the stability of the local soil is not adequate for supporting wheel loads, the properties are

improved by soil stabilization techniques. Thus the principle of soil stabilized road construction

involves the effective utilization of local soils and other suitable stabilizing agents.

Earthwork as an important part of road construction

In any highway engineering work the construction of the embankment or the sub

grade is a very important activity. The earthwork constitutes 30% of the cost of the road

project. The pavement directly rests on the artificially prepared soil sub grade and thus

derives considerable strength from it. The adequate design and construction of

embankments is therefore the key to the successful performance of the roads.

1.2 Desirable properties of Sub grade soil

Stability

Incompressibility

Permanency of strength

Minimum changes in volume and stability under adverse condition

Good drainage

Ease of compaction

The soil should possess adequate stability or resistance to permanent

deformation under loads and should possess resistance to weathering thus

retaining the desired subgrade support. Minimum variation in volume will ensure

minimum variation in differential expansion and differential strength values. Good

drainage is essential to avoid excessive moisture retention and to reduce the

potential frost action. Ease of compaction ensures higher dry density and strength under

particular type and amount of compaction (1)

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1.3 Objective of present study

To characterize the soil under investigation based on its index properties.

To classify the soil as per IRC Classification.

To compare the OMC of the given soil & to achieve Maximum Dry density by

Proctor compaction tests.

To determine the strength of soil by Triaxial method.

To study the effect of RBI-81 and Silica Fume on soil by varying percentage.

To determine the strength enhancement of the given soil with stabilizer.

To determine the thickness by conventional method and Annexure method.

To compare the variation in cost by above method.

1.4 Scope of present study

The present study deals with the testing of soil properties of soil sample. The

following tests were done on the soil:

Grain size analysis

Atterberg limits

Compaction

California bearing ratio

Triaxial test

The soil is stabilized with a commercially available stabilizer called Road

Building International -81 (RBI-81) and the strength enhancement of the soil is

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studied. And also compared with replacing RBI-81 with Silica fume, strength

enhancement is studied. Economically low cost design studies are done.

CHAPTER-2

LITERATURE REVIEW

2.1 General

Subgrade soil is an integral part of the road pavement structure as it provides the

support to the pavement from beneath. The main function of the subgrade is to give adequate

support to the pavement and for this the subgrade should posses’ sufficient stability under

adverse climatic and loading conditions .The formation of waves, corrugations, rutting and

shoving in black top pavements and the phenomenon of pumping, blowing and consequent

cracking of cement concrete pavements are generally attributed due to the poor subgrade

conditions.

When soil is used in embankment construction, in addition to stability

incompressibility is also important as differential settlement may cause failures. Compacted soil

and stabilized soil are often used in sub – base or base course of highway pavements. The soil is

therefore considered as one of the principle highway materials. (1)

2.2 Characteristics of soil

Soil consists mainly of mineral matter formed by the disintegration of rocks, by the

action of water, frost, temperature, pressure or by plant or animal life. Based on the individual

grain size of soil particles, soils have been classified as gravel, sand, silt and clay. The

characteristics of soil grains depend on the size, shape, surface texture, chemical composition

and electrical surface charges. Moisture and dry density influence the engineering behavior of a

soil mass. (1,2,3)

2.3 Index properties of soil

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The wide range of soil types available as highway construction materials have made it

obligatory on the part of the highway engineer to identify and classify the different soils. The soil

properties on which their identification and classification are based on are known as index

properties. The index properties which are generally used are grain size distribution, liquid limit,

plastic limit and plasticity index. (1,2,3)

Grain size analysis

The grain size distribution is found by mechanical analysis. The components of soils

which are coarse grained may be analyzed by sieve analysis and the soil fines by sedimentation

analysis. The grain size analysis or the mechanical analysis is hence carried out to determine the

percentage of individual grain size present in a soil sample. (1,2,3)

Consistency limits and indices

The physical properties of fine grained soils, especially of clays differ very much at

different water contents. Clay may be almost in a liquid state, or it may show plastic behavior or

may be stiff depending on the moisture content. Plasticity is a property of outstanding

importance for clayey soils, which may be explained as ability to undergo changes of shape

without rupture. Atterberg in 1911 proposed a series of tests, mostly empirical, for the

determination of the consistency and plastic properties of fine soils. These are known as

Atterberg limits and indices.

Liquid limit may be defined as the minimum water content at which the soil will flow

under the application of very small shearing force. It is determined usually in the laboratory

using a mechanical device.

Plastic limit may be defined as the minimum moisture content at which the soil remains

in a plastic state. The lower limit is arbitrarily defined and determined in the laboratory by a

prescribed test procedure.

Plasticity index is defined as the numerical difference between the liquid and the plastic

limits. Plasticity index thus indicates the range of moisture content over which the soil is in

plastic condition.(1,2,3)

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2.4 Determination of soil properties

There are various tests that are carried out to determine the various properties of the soil

1. Liquid limit: The water content at which the soil has a small shear that it flows to close a

groove of standard width when jarred in a specified manner.

2. Plastic limit: The plastic limit is the water content at which the soil to crumble when rolled

into threads of specified size.

3. Plasticity index: The amount of water which must be added to change a soil from its

plastic limit to its liquid limit is an indication of the plasticity of the soil. The plasticity is

measured by the “plasticity index” which is equal to the liquid limit minus the plastic limit.(5)

4. Grain size analysis: It is also known as mechanical analysis of soils is the determination of

the percentage of individual grain sizes present in the sample. The results of the test are of

great value in soil classification. There are two methods of sieve analysis :

(i) wet sieving applicable to all soils and

(ii) Dry sieving applicable to soils having negligible proportion

of clay and silt. (3)

5. Compaction test: This test is carried out to find out the optimum moisture content and the

maximum dry density of the given soil(2,3).

2.5 Sub-grade soil strength

The factors on which the strength characteristics of soil depend are:

(i) Soil type

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(ii) Moisture content

(iii) Dry density

(iv) Internal structure of the soil and

(v) The type and mode of stress application (1).

2.5.1 Evaluation of soil strength

The tests used to evaluate the strength properties of soils may be broadly divided into

three groups:

(i) Shear test

(ii) Bearing test and

(iii) Penetration test.

The following tests were carried out in the present study to find the strength of the soil

1. CBR test: This test was developed by the Californian Division of highways as a method of

classifying and evaluating soil sub-grade and base course materials for flexible pavement. The

CBR is a measure of resistance of a material to penetration of standard plunger under

controlled density and moisture conditions.

2. Triaxial compression test: This test is carried to evaluate the in-situ strength of the soil

sample under controlled loading.(2,3,)

Table: Density requirement of embankment and subgrade

Type of work Maximum laboratory dry unit weight when

tested as per IS:2720(part 8)

Embankments up to 3 meters

Height, not subjected to expensive flooding.Not less than 15.2kN/cu.m.

Embankments exceeding 3 meters height or

embankments of any height subject to long

periods of inundation

Not less than 16.0kN/cu.m.

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Subgrade and earthen Shoulders/ verges/

backfill Not less than 17.5kN/cu.m.

2.6 Soil stabilization using powder based inorganic stabilizer

The effectiveness of this stabilizer both plastic & non-plastic soils is studied by carrying

out a detailed laboratory study. Different types of soils that is gravelly, sandy, silty, clayey are

stabilized with inorganic stabilizer in the range of 2-12%. Apart from the study of geotechnical

properties of individual soils, strength in terms of UU & CBR of stabilized soils was evaluated.

The selected soils viz. gravelly, sandy & silty are observed to be non-plastic. Clayey soil

is observed to be highly compressible in nature.

The Triaxial strength of all the soils increases with the addition of stabilizer content for

different curing periods. The rate of increase is more in silty & gravelly soils as compared

to sandy & clayey soils.

The CBR value increases with stabilizer content for all soils. It is observed that the value

increases significantly after addition of 2% content. The rate of increase is more in

gravelly & silty soils as compared to sandy & clayey soils.

Gravelly soil with 6% & silty soil with 4% stabilizer content may be used as a sub-base

layer of pavement. Gravelly & silty soils with 8% stabilizer content may be used as a

base layer of pavement.

All the soils stabilized with 2% stabilizer content may be used for shoulder construction.

It can be concluded that powder based inorganic stabilizer has the potential for

stabilization of gravelly & silty soils to make it suitable for its use in improved sub

base/base layer/shoulder construction of a road pavement. Solution to a typical practical

problem indicated substantial reduction in the total pavement thickness which not only

reduces the total cost but also avoids the use of natural depleting conventional materials.

Test tracks of suitable length may be constructed & monitored over a period of time

before adopting such specifications for large scale field applications.

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2.7 Stabilized road

If the stability of the local soil is not adequate for supporting the wheel loads, the

properties are improved by soil-stabilization techniques. Thus the principle of soil stabilized road

construction involves the effective utilization of local soils and other suitable stabilizing agents.

The term soil stabilization means the improvement of the stability or bearing power of

the soil by the use of controlled compaction, proportioning and or the addition of suitable

admixture or stabilizers. Soil stabilization deals with physical physico-chemical and chemical

methods to make the stabilized soil serve its purpose as a pavement component material. (1,4)

2.7.1 Advantages of stabilization

(i) It improves the engineering properties of poor soils as well as enhancing that of good

soils to meet the specified requirements.

(ii) It helps reduce the need of existing borrow pit materials and prospecting of new

borrow pit sources there by protecting environment.

(iii) It eliminates the need for the landfill sites for dumping of poor materials and

environmental harmful materials as well as construction waste

(iv) It allows faster construction because removal of substandard material and

transportation of good materials is not required.

(v) Time saved also adds to cost saving of the project and allows more projects to be

undertaken and complete within the same time frame.

2.7.2 Properties of stabilization

Bonds soil particles together (increases strength & stiffness).

Reduces permeability (fills voids, forms membrane).

Improves compaction (lubrication, particle restructuring).

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2.7.3 Features & Benefits

Higher resistance (R) values

Reduction in plasticity

Lower permeability

Reduction of pavement thickness

Elimination of excavation, material hauling and handling, and base importation

Aids compaction

Provides "all-weather” access onto and within project sites.

The principles are:

Evaluating the properties of given soil

Deciding the method of supplementing the lacking property by the effective and economical

method of stabilization.

Designing the stabilized soil mix for intended stability and durability values.

RBI Grade 81 soil stabilizer is an advanced technological development with economic and

environmental benefits. It is a unique, environmentally friendly, comprehensive and irreversible

inorganic stabilizer for road construction. The technology was developed by scientists incorporating

natural materials with well proven efficacy and durability. It has undergone a rigorous development and

verification process internationally coordinated by Road Building International and has been granted an

international patent. Road Building International has engineered an inorganic product:

is extremely effective

whose action is irreversible

is produced from natural ingredients

is capable of providing rapid infrastructure development progress while preserving the

environment by using the in-situ natural soil.

Avoids the environmental burdens associated with conventional road construction.

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RBI Grade 81 can be effectively applied to all soil types:

• In-situ application with RBI Grade 81 causes no interruption to traffic.

• Resultant cost savings of 60% (in comparison to conventional methods).

• RBI Grade 81 avoids the otherwise necessary removal and dumping of asphalt (5).

2.7.4 Properties of RBI-81 stabilizer

Table 2.1: properties of RBI-81 stabilizer(5)

CHEMICAL COMPOSITION

POWDER

Properties % by mass

Ca CaO- 52-56

Si SiO215-19

S SO3 9-11

Al Al2O3 5-7

Fe Fe2O3 0-2

Mg MgO 0-1

Mn, K, Cu, Zn Mn+K+Cu+Zn 0,1-0,3

H2o 1-3

Fibers (polypropylene) 0-1

Additives 0-4

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2.8 Silica fume

2.8.1 Definition for silica fume

The American Concrete Institute (ACI) defines silica fume as “very fine non-

Crystalline silica produced in electric arc furnaces as a by-product of the production of elemental

silicon or alloys containing silicon” (ACI 116R). It is usually a gray colored powder, somewhat

similar to Portland cement or some fly ashes(6,7).

2.8.2 Pozzolanic — will not gain strength when mixed with water. Examples include silica

fume meeting the requirements of ASTM C 1240, Standard Specification for Silica Fume Used

in Cementitious Mixtures, and low-calcium fly ash meeting the requirements of ASTM C 618,

Standard Specification for Coal Ash and Raw or Calcined Natural Pozzolanic for Use in

Concrete, Class F.

2.8.3 Cementitious — will gain strength when mixed with water. Examples include ground

granulated blast-furnace slag meeting the requirements of ASTMC989, Standard Specification

for Ground Granulated Blast-Furnace Slag for use Concrete and Mortars, or high-calcium fly

ash meeting the requirements of ASTM C 618, Class C.

2.8.4 Production

Silica fume is a by-product of producing silicon metal or ferrosilicon alloys in

smelters using electric arc furnaces. These metals are used in many industrial applications to

include aluminum and steel production, computer chip fabrication, and production of silicones,

which are widely used in lubricants and sealants. While these are very valuable materials, the by-

product silica fume is of more importance to the concrete industry(7).

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Fig shows production of Silica

Fig 1.2 EMISSION OF SILICA FUME

Figure 1.2 shows a smelter in the days before silica fume was being captured for use in concrete

and other applications. The “smoke” leaving the plant is actually silica fume. Today in the

United States, no silica fume is allowed to escape to the atmosphere. The silica fume is collected

in very large filters in the bag house and then made available for use in concrete

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2.9 Chemical Properties

Amorphous. This term simply means that silica fume is not a crystalline material. A

crystalline material will not dissolve in concrete, which must occur before the material can react.

Don’t forget that there is a crystalline material in concrete that is chemically similar to silica

fume. That material is sand. While sand is essentially silicon dioxide (SiO2), it does not react

because of its crystalline nature.

Trace elements. There may be additional materials in the silica fume based upon the metal

being produced in the smelter from which the fume was recovered. Usually, these materials have

no impact on the performance of silica fume in concrete.

2.10 Physical Properties

Particle size. Silica fume particles are extremely small, with more than 95%

of the particles being less than 1 µm (one micrometer). Particle size is extremely important for

both the physical and chemical contributions (discussed below) of silica fume in concrete.

Bulk density. This is just another term for unit weight. The bulk density of the as-

produced fume depends upon the metal being made in the furnace and upon how the furnace is

operated. Because the bulk density of the as-produced silica fume is usually very low, it is not

very economical to transport it for long distances.

Specific gravity. Specific gravity is a relative number that tells how silica fume compares

to water, which has a specific gravity of 1.00. Silica fume has a specific gravity of about 2.2,

which is somewhat lighter than portland cement, which has a specific gravity of 3.15.

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PHYSICAL PORPERTIES OF SILICA FUME(7)

Specific surface.

Specific surface is the total surface area of a given mass of a material. Because the particles

of silica fume are very small, the surface area is very large. We know that water demand

increases for sand as the particles become smaller; the same happens for silica fume. This fact is

why it is necessary to use silica fume in combination with a water-reducing admixture or a super

plasticizer. A specialized test called the “BET method” or “nitrogen adsorption method” must be

used to measure the specific surface of silica fume. Specific surface determinations based on

sieve analysis or air-permeability testing are meaningless for silica fume.

Figure 2.1

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Figure2.1. Photomicrograph of Portland cement grains (left) and silica-fume particles (right) at

the same magnification. The longer white bar in the silica fume side is 1 micrometer long. Note

that ACI 234R, Guide for the Use of Silica Fume in Concrete, estimates that for a 15 percent

silica-fume replacement of cement, there are approximately 2,000,000 particles of silica fume for

each grain of Portland cement.

Chemical contributions

Because of its very high amorphous silicon dioxide content, silica fume is a very reactive

pozzolanic material in concrete. As the Portland cement in concrete begins to react chemically, it

releases calcium hydroxide. The silica fume reacts with this calcium hydroxide to form

additional binder material called calcium silicate hydrate, which is very similar to the calcium

silicate hydrate formed from the portland cement.

Physical contributions

Adding silica fume brings millions and millions of very small particles to a concrete

mixture. Just like fine aggregate fills in the spaces between coarse aggregate particles, silica

fume fills in the spaces between cement grains. This phenomenon is frequently referred to as

particle packing or micro-filling. Even if silica fume did not react chemically, the micro-filler

effect would bring about significant improvements in the nature of the concrete. Below table

present a comparison of the size of silica-fume particles to other concrete ingredients to help

understand how small these particles actually are.

2.11 Soil stabilization methods

The methods of soil stabilization which are in common use are:

(i) Chemical Stabilization

(ii) Mechanical stabilization(1)

2.11.1 Effects of stabilization

Soil stabilization may result in any one or more of the following changes:

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1. Increase in stability, change in properties like density or swelling, change in

physical characteristics.

2. Change in chemical properties.

3. Retaining and desired strength by water proofing(1)

2.12 Techniques of soil stabilization

Based on the above principles, the various technique of soil stabilization may be grouped

Proportioning technique

1. Cementing agents

2. Modifying agents

3. Water proofing agents

4. Water repelling agents

5. Water retaining agents

6. Heat treatment

7. Chemical stabilization

8. In all the above methods, adequate compaction of the stabilized layers is the most

essential requirement. (1)

2.13 Design and cost estimation.

As per IRC-37 the conventional methods was used to calculate the thickness of different

layer, which was further compared with IRC-37 Annexure method difference in thickness is

calculated. (8)

The cost which are involved for materials were taken from Schedule Rate (SR), and

calculated. (9)

CHAPTER-3

PRESENT INVESTIGATION

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3.1 General Studies:

Soil is one of the principle materials of construction in soil embankments and in

stabilized soil base and sub-base courses.

Various types of soil have various properties at different stretch of the sub grade.

Thus, it is important to carry out basic soil tests at a stretch of 300mts.

In view of the wide diversity in soil type, it is desirable to classify the subgrade soil

into groups possessing similar physical properties.

In the present investigation the soil is classified on the basis of simple laboratory

tests such as grain size analysis and consistency limit tests.

Soil compaction is an important phenomenon in highway construction as compacted

subgrade improves the load supporting ability of the pavement; in turn resulting in pavement

thickness requirement. Compaction of earth embankments would result in decreased

settlement. Thus the behavior of soil subgrade material could be considerably improved by

adequate compaction under controlled conditions. The laboratory compaction tests are

conducted and the optimum moisture content at which the soil should be compacted and the

dry density that should be achieved at the construction site has been determined.

Soil for the present study was obtained from the project site. The basic tests like

Atterberg limits, compaction test, California bearing resistance & Triaxial test was done to

characterize the soil based on its properties.

The representative soils were stabilized using the stabilizers Road Building

International-81 and Silica Fume for different proportions i.e. 1%, 2% and 4% stabilizer to

assess their properties and the results were analyzed. Road Building International has

engineered as an inorganic product:

• Is capable of providing rapid infrastructure development progress while preserving

the environment by using the in-situ natural soil.

24

• Avoids the environmental burdens associated with conventional road construction. In

the present study, soil was subjected to basic tests like:

• Grain size analysis

• Atterberg limits

• Compaction

• California bearing ratio test

• Triaxial test (at 0.7, 1.4 and 2.1 kg/sqcm confinement)

3.2 Laboratory test conducted on soil: (2,3)

3.2.1 Grain size analysis:

The percentage of various sizes of particle in a given dry soil sample is determined by

grain size analysis. Grain size analysis also knows as mechanical analysis of soils is the

determination of the percent of individual grain sizes present in the sample.

Fig 1: Indian standard grain size soil classification system

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Fig-3.1 Sieve Analysis Apparatus

3.2.2 Atterberg limits:

By consistency is meant the relative ease with which soil can be deformed. This

term is mostly used for fine grained soils for which the consistency is related to a large

extent to water content. Consistency denotes degree of firmness of the soil which may be

termed as soft, firm, stiff or hard. In 1911 Atterberg divided the entire range from liquid to

solid state into four stages liquid state, plastic state, semi -solid state and solid state. He

set arbitrary limits known as consistency limits or Atterberg limits, for these divisions in

terms of water content. Thus the consistency limits are the water contents at which the soil

mass passes from one state to the next.

Liquid limit (WI): It is defined as the minimum water content at which the soil is

still in the liquid state, but has a small shearing strength against flowing which can be

measured by standard available means. With reference to the standard liquid limit device,

it is defined as the minimum water content at which a part of soil cut by a groove

of standard dimensions will flow together for a distance of 12mm under an impact of 25

26

blows in the device.

Plastic limit (WP): plastic limit is the water content corresponding to an arbitrary limit

between the plastic and the semi-solid states of consistency of a soil. It is defined as the

minimum water content at which a soil will just begin to crumble when rolled

into a thread approximately 3mm in dia.

3.2.3 Compaction test:

Compaction of soil is a process by which the soil particles are constrained to be packed

more closely together by reducing the air voids. It causes decrease in air voids and consequently

increases in dry density. This may result in increase in shearing strength. Degree of compaction

is usually measured quantitatively by dry density.

Compaction refers to a more or less rapid reduction mainly in the air voids under a loading of

short duration Increase in dry density of soil due to compaction mainly depends on two factors.

Compacting moisture content

The amount of compaction.

3.2.4 California bearing ratio test (CBR):

The CBR is a measure of resistance of a material to penetration of standard

plunger under controlled density and moisture conditions. CBR test is mainly utilized for

the design of pavement structure. The test is simple and has been extensively

investigated for field correlations of flexible pavement thickness requirement.

The test consists of causing a cylindrical plunger of 50mm diameter to penetrate a

pavement component material a 1.25mm/min. The load for 2.5mm and 5mm are

recorded. This load is expressed as a percentage of standard load value at a

respective deformation level to obtain CBR value.

27

Fig-3.2 CBR mould preparation Fig 3.3- CBR Testing Machine

3.2.5 Triaxial compression test:

The triaxial compression test in which the test specimen is compressed by

applying all the three principal stress. The cell pressure in the triaxial cell is also called

the confining pressure.

Fig-3.4 Triaxial testing machine Fig-4.5 Mould Extractor

28

CHAPTER-4

ANALYSIS OF RESULTS

4.1 General

The laboratory tests for the various properties of the soil were conducted and the results thus obtained are tabulated and analyzed.

The test was conducted on locally available soil and the properties were compared with

and without the use of stabilizer.

4.2 Laboratory tests on soil material

4.2.1 Wet sieve analysis

Sample Calculation:

Sample: Native Red Soil

Wt of sample taken: 500gms

Table 4.1 shows the sample calculation

sample Red Soil

sieve size

Wt of sample reained

cumulative Wt retained cum % wt ret %fine passing

4.75 122.17 122.17 24.434 75.566

2.36 24.44 146.61 29.322 70.678

1.18 41.22 187.83 37.566 62.434

0.6 40.65 228.48 45.696 54.304

0.425 29.94 258.42 51.684 48.316

0.15 36 294.42 58.884 41.116

0.075 9.59 304.01 60.802 39.198

Gravel Sand Fines24.434 24.434 24.434

29

0

10

20

30

40

50

60

70

80

Seive size

Graph of wet sieve analysis

Type of soil as per IS-Classification: Sandy Clayey (SC) Soil

4.2.2 Atterberg limit: Native Red Soil

Table 4.2 shows the liquid limit calculation

30

Cu=23.54

Cc=3.1

No of blows M/C %10 45.9413 44.0824 42.5829 41.72

Table 4.2.1 shows Plastic limit

M/C container No 123 75 52 21Wt of container gms (W1) 23.86 21.98 27.18 40.47Wt of cont + wit soil (W2) 26.03 23.58 29.15 42.34Wt of cont + dry soil % (W3) 25.54 23.23 28.71 41.92

M/c % 29.17 28.00 28.76 28.97 28.72

Remarks

LL "from graph" 42.4PL 28.72PI 13.68

Liquid limit and Plastic Index table

soil Native(RS) RS+1% RBI RS+2% RBI RS+4% RBI RS+1% SF RS+2% SF RS+4% SF

LL 42.4 42 41.61 40.01 40 39.57 38.6

PL 28.72 28.74 28.76 27.92 26.97 27.51 26.93

PI 13.68 13.24 12.87 12.09 13.03 12.06 11.63

0 0.5 1 1.5 2 2.5 3 3.5 4 4.510.5

11

11.5

12

12.5

13

13.5

14

RBI-81% SF

% dosage

PI

31

4.2.3 Compaction test

Sample Calculation:

Sample: Red Soil

Type of Compaction : Modified Proctor

Type of Soil : New

Type of Mould : Small

Type of Hammer : 4.89

No. of Layers : 5

No. of Blows : 25

Table 4.2.2 shows the sample calculation

Moisture Content (%) Bulk Density (g/cc) Dry Density (g/cc)9.07 1.90 1.74

11.33 1.96 1.7612.91 2.11 1.8614.73 2.12 1.8516.41 2.08 1.79

8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.001.65

1.70

1.75

1.80

1.85

1.90

M/C (%)

Dry D

ensit

y(gm

/cc)

32

OMC=13.54%

MDD=1.877gm/cc

Remarks: MDD and OMC for different % are of RBI-81 & Silica Fume.

Type of Stabilizer Native(RS) RBI-81 Silica fumepercentage 0% 1% 2% 4% 1% 2% 4%Compaction

OMC (%) 13.54 13.48 13.52 13.89 12.34 13.16 13.1MDD (gm/cc) 1.877 1.882 1.887 1.869 1.887 1.893 1.94

4.2.4 California bearing ratio test

Sample Calculation:

Sample: Red Soil

Area of plunger = 19.64cm2

CBR = 8% (This has been assumed as per Guidelines) (1), the value is on lower side.

4.2.5 Triaxial Compression Test:

Sample Calculation: Red soil

Specimen details:

Diameter: 3.8cm

Height: 7.6cm

Volume, V = (πd2/4) * h

= (π*3.82/4) * 7.6

V = 86.19 cm3

Mass = volume * density

= 86.19 * 1.87

= 167.48gms

Water = 13.54% * 161.78

= 20.07gms

33

RBI Silica Fume

1.0% = 1.62 gms 1.63gms

2.0% = 3.52 gms 3.26gms

4.0% = 6.44 gms 6.69gms

The above calculated mass of soil, water and RBI according to varying percentages are mixed together and put into the mould, mould is extracted and placed for moist curing for 3days.

Table 4.2.5 sample calculation at different confining pressure says 0.7, 1.4 and 2.1kg/cm2.

Native Red soil cm mm pressure(σ 31) kg/cm2 2.1

length of specimen 7.6 76 Load at Failure (kg)

Dia of specimen 3.8 38 least count (dial gauge), mm 0.001

area of specimen(Ai) 11.34 1133.90 least count ( proving ring), mm 0.002

dial gauge

∆ (mm)

proving

load(kg) Strain()

Corrected area

Ac=(Ai/(1-)cm2

Stress (kg/cm2)

noted taken readings

0 0.00 0 0 0 0.00E+00 11.339 0.00 10 0.01 3 3 0.66 1.32E-04 11.338 0.06 20 0.02 4 4 0.88 2.63E-04 11.336 0.08 30 0.03 1 5 1.1 3.95E-04 11.335 0.10 40 0.04 1.2 7 1.54 5.26E-04 11.333 0.14 50 0.05 1.2 7 1.54 6.58E-04 11.332 0.14 60 0.06 2.2 12 2.64 7.89E-04 11.330 0.23 70 0.07 4.3 23 5.06 9.21E-04 11.329 0.45 80 0.08 9.2 47 10.34 1.05E-03 11.327 0.91 90 0.09 13.1 66 14.52 1.18E-03 11.326 1.28

100 0.10 17.4 89 19.58 1.32E-03 11.324 1.73 110 0.11 1+2.3 113 24.86 1.45E-03 11.323 2.20 120 0.12 8.1 141 31.02 1.58E-03 11.321 2.74 130 0.13 12.3 163 35.86 1.71E-03 11.320 3.17 140 0.14 17.2 187 41.14 1.84E-03 11.318 3.63 150 0.15 2+2.3 213 46.86 1.97E-03 11.317 4.14 160 0.16 7.4 239 52.58 2.11E-03 11.315 4.65 170 0.17 12.1 261 57.42 2.24E-03 11.314 5.08 180 0.18 18.2 292 64.24 2.37E-03 11.312 5.68 190 0.19 3+3.4 319 70.18 2.50E-03 11.311 6.20

34

200 0.20 9 345 75.9 2.63E-03 11.309 6.71 210 0.21 14.4 374 82.28 2.76E-03 11.308 7.28 220 0.22 4+.2 402 88.44 2.89E-03 11.306 7.81 230 0.23 -0.1 401 94.6 3.03E-03 11.305 7.80 240 0.24 .4 398 99.88 3.16E-03 11.303 7.78 250 0.25 1.3 394 100.76 3.29E-03 11.302 7.73 260 0.26 1.4 391 111.32 3.42E-03 11.300 7.64

Table 4.2.6 Shear Strength obtained for Native soil (RS)

σ 31(Kg/cm2)ShearStrength

(kg/cm2)%Dosage

0.7 0.21301.4 0.287

2.1 0.311

Annexure 1: Shows Triaxial compression test Graphs with different %dosage at 0.7, 1.4 and

2.1kg/sqcm confinement pressure.

35

Deviator stress (σd=F/Ac)

1.294

Normal Stress (σ 11)kg/cm2

3.394

Table 4.2.7 Abstract of Triaxial Test Result.

Sample Native Soil

sl noload area'Ac' Stress (Kg/cm) Atterberg limits E3 value

Kg Sqcm σ 31 σ d σ 11 LL PI Kg/sqcm Mpa1 4.93 11.267 0.7 0.962 1.662 42.04 13.68 2430 238.302 5.87 11.284 1.4 1.001 2.401 42.04 13.68 2580 253.013 7.81 11.28 2.1 1.293 3.393 42.04 13.68 2751 269.78

SampleNative Soil + 1%

RBI81

sl noload area'Ac' Stress (Kg/cm) Atterberg limits E3 value

Kg Sqcm σ 31 σ d σ 11 LL PI Kg/sqcm Mpa1 7.59 11.289 0.7 0.437 1.137 42 13.24 3500 343.232 10.35 11.312 1.4 0.519 1.919 42 13.24 3622 355.203 11.33 11.29 2.1 0.692 2.792 42 13.24 3667.67 359.68


RBI81

sl noload Area 'Ac' Stress (Kg/cm) Atterberg limits E3 value



RBI81



Sample Native Soil + 1%Silica

36

Fume


Kg Sqcm σ 31 σ d σ 11 LL PIKg/sqcm Mpa

1 8.86 11.284 0.7 1.021 1.721 40.00 12.96 3689 361.772 11.55 11.259 1.4 1.133 2.533 40.00 12.96 3846 377.173 12.61 11.275 2.1 1.701 3.801 40.00 12.96 4000 392.27

SampleNative Soil + 2%Silica

Fume



1 11.52 11.281 0.7 0.785 1.485 39.47 12.04 3816 374.222 12.76 11.294 1.4 1.023 2.423 39.47 12.04 4000 392.273 19.18 11.287 2.1 1.117 3.217 39.47 12.04 4966 487.00

SampleNative Soil + 4%Silica

Fume



1 14.37 11.284 0.7 1.273 1.973 38.60 11.62 4333.3 424.952 21.44 11.275 1.4 1.902 3.302 38.60 11.62 5000 490.343 23.7 11.25 2.1 2.107 4.207 38.60 11.62 5125 502.59

37

Table 4.2.8 sample calculation at different confining pressure says 0.7, 1.4 and 2.1kg/cm2.

Sl No.

Type of soil

Days Confinement pressure (kg/cm 2 )

E3 in kg/cm 2

0% 1% 2% 4%

1) Native Soil(RS)

3 0.7 2430 - - -

1.4 2580 - - -

2.1 2751 - - -

1) RS + % RBI-81

3 0.7 - 3500 3600 3743

1.4 - 3622 3681 4090

2.1 - 3733 4090 4600

3) RS +% Silica Fume

3 0.7 - 3689 3816 4333

1.4 - 3846 4000 5000

2.1 - 4333 4966 5125

Table 4.2.10 Test result for %Dosage for 1.4 kg/cm2 confinements

Atterberg limits

LoadShear parameter E3 value

Soil + % Stabilizer

LL PI Kg σ 31

(Kg/cm2)

σ d

(Kg/cm2)

Shear strength(Kg/cm2)

Kg/cm2 Mpa

Native (RS) 42.04 13.68 5.87 1.4 0.519 0.287 2580253.0

1

RS+1% RBI-81 42 13.24 10.35 1.4 0.917 0.361 3622355.2

0

RS+2% RBI-81 41.61 12.87 11.29 1.4 1.001 0.507 3681360.9

8

RS+4% RBI-81 40.01 12.09 15.47 1.4 1.370 0.674 4090401.0

9

RS +1% SF 40 13.03 11.35 1.4 1.023 0.417 3846377.1

7RS +2% SF 39.57 12.06 12.76 1.4 1.133 0.571 4000 392.2

38

7

RS +4% SF 38.6 11.63 21.44 1.4 1.903 0.922 5000490.3

4

Table 4.2.11 Shear Strength obtained for Native soil (RS) with % Dosage

σ 31(Kg/cm2)

Shear Strength kg/cm2

Red soil (RS)

RS+1% RBI-81

RS+2% RBI-81

RS+4% RBI-81

RS+1% SF

RS+2% SF

RS+4% SF

0.7 0.213 0.308 0.434 0.557 0.337 0.534 0.811

1.4 0.287 0.361 0.507 0.674 0.417 0.571 0.922

2.1 0.311 0.422 0.581 0.791 0.454 0.652 1.032

4.3. Design of pavement:

Method 1: By IRC-37 CBR method,

Enter the Values For Design of Flexible Pavement as per ‘IRC37 Guidelines’

CBR value (%)8

Length of road 40 km

Type of Road 4 Lane Dual carriage way

Design life 'n' 10IRC 37 Guidelines

Growth factor 'r'0.07

VDF value 'F'4.5

Lane distribution factor 'D'0.75

Initial traffic in the year of completion (CVPD) 'A'

5000

Cumulative num of standard axle 'N' 85.101 msa

39

N= (365*((1+r) n -1)*A*D*F)/r

A=P (1+r) x

Table shows Thickness obtained for different layers by CBR method,

As per CBR method obtained thickness (mm) 630

Indivial layer thickness unit mt cm mm

BM0.04 4 40

DBM0.14 14 140

Base0.25 25 250

Sub-Base0.2 20 200

total0.63 63 630

Method 2: By IRC-37 Annexure1 method,

Moduls of Elasticity of Subgrade, Sub-base and Base layers

Step1 Input the data

Elastic Modulus of Subgrade 'E3' (Mpa)254.5686

Thickness of Granular Layer 'h' (mm) / H2 450

Composite Elastic Modulus of granular Sub-Base and base 'E2' (Mpa)E2=E3*0.2*h0.45

795.76Step2

Elastic Modulus of RBI81 'E1' (Mpa)505.68375

Thickness of Granular Layer H2 (mm)450

Changed thickness using stabilizer 'H1' (mm) 565

40

((E1 (H1)3)/ 12(1-µ12))= ((E2 (H2)3)/12(1-µ2

2))

From the above formula we calculate ‘H1’, µ is the Poisson’s ratio.

Table 4.2.12 shows the thickness variation with different %Dosage

soil Native(RS)RS+1% RBI RS+2% RBI

RS+4% RBI RS+1% SF RS+2% SF

RS+4% SF

composite Elastic modulus of Granular Sub Base and Bas Layer(mm) E2Kg/cm2 - 8114 8114 8114 8114 8114 8114

Mpa - 795.76 795.76 795.76 795.76 795.76 795.76Thickness reqd - 588 584 564 576 568 528rounded thickness

-590 585 565

575 570 530

chip carpet - 20 20 2020 20 20

Total thickness - 610 605 585595 590 550

Table 4.2.13 shows the thickness variation by different layers

soil + % RBI Native RS

RS+1 % RBI

RS+2 % RBI RS+4 % RBI

RS+1 % SF RS+2 % SF RS+4 % SFThickness (mm)

BC 40 - -- - - -- -

DBM 140 - - - - - -

chip carpet - 20 20 20 20 20 20

BASE (WMM) 250590 585 565 575 570 530

SUBBASE (GSB) 200

total Thickness 630 610 605 585 595 590 550

41

4.4. Materials Quantity

Considering 4-lane dual carriage way with 4mt wide median and 2mt paved shoulder on either side.

Table 4.2.13 materials required per km stretch.

Materials required per Km in cum (as per IRC-37 CBR method)

Native soil thickness (mm) Qty (cum)BC 880

DBM 3080BASE (WMM) 5500

SUBBASE (GSB) 4400

Table 4.2.14 materials required per km stretch.

Soil + % Stabilizer

material Required per Km

BM DBM Chip carpet Base Sub-BaseB&SB

ReplacedStabilizer

Required(m3)

Unitm3 m3 m2 m3 m3 m3 RBI-81

Silica Fume

RS+1% RBI-81 - - 22000 - 12980 130 -RS+2% RBI-81 - - 22000 - - 12870 257 -RS+4% RBI-81 - - 22000 - - 12430 497 -

RS +1% SF - - 22000 - - 12650 - 127RS +2% SF - - 22000 - - 12540 - 251RS +4% SF - - 22000 - - 11660 - 466

42

4.5. Cost analysis,Cost are estimated based on scheduled rates and are noted6.

Table 4.2.15 Cost involved per m3

Cost per m3 (in Rs.) as per SR PWD

BM DBM Base Sub-Base Chip carpet B&SB Replaced

Stabilizer per m3

m3 m3 m3 m3 m2 m3 RBI-81 Silica Fume

6000 5500 1400 1100 280 350 37 5

Table 4.2.16 Cost involved per km of stretch as per CBR method design

Materials required(cum) and cost involved per Km as per IRC-37 CBR method

native soil qty rate per cum Amount(Rs.)BC 880 6500 57,20,000.00DBM 3080 5500 1,69,40,000.00BASE (WMM) 5500 1450 79,75,000.00SUBBASE (GSB) 4400 1100 48,40,000.00

Total cost(Rs). 3,54,75,000.00

43

Table 4.2.17 Cost involved per km of stretch as per IRC-37 Annexure1 method.

Material required per Km and cost estimated as per IRC-37 annexure method

qtyrate(Rs.

) amount(Rs.)

qtyrate(Rs.

) amount(Rs.)RBI 1% SF 1%

Chip carpet( sqm) 22000 285

62,70,000.00

Chip carpet sqm 22000 285

62,70,000.00

RBI in kgs11700

0 36 42,12,000.00 SF in kgs

190500 6

11,43,000.00

soil in cum 12980 350 45,43,000.00 soil in cum 12980 350

45,43,000.00

Total Cost

1,50,25,000.00 Total Cost

1,19,56,000.00

qtyrate(Rs.

) amount(Rs.)

qtyrate(Rs.



62,70,000


62,70,000.00

RBI in kgs23130

0 36 83,26,800 SF in kgs

376500 6

22,59,000.00

soil in cum 12870 350 45,04,500 soil in cum 12870 350

45,04,500.00

Total Cost 1,91,01,300 Total Cost

1,30,33,500.00

qtyrate(Rs.

) amount(Rs.)

qtyrate(Rs.



62,70,000


62,70,000.00

RBI in kgs44730

0 36 1,61,02,800 SF in kgs

684000 6

41,04,000.00

soil in cum 12430 350 43,50,500 soil in cum 12430 350

43,50,500.00

Total Cost Total Cost

44

2,67,23,300 1,47,24,500.00

Table 4.2.18 Abstract of Modulus of sub grade, plastic index, thickness and cost with % relationship at 1.4kg/sqcm confinement pressure.

soil + % RBI

Native RS RS+1 % RBI

RS+2 % RBI

RS+4 % RBI

RS+1 % SF RS+2 % SF RS+4 % SF

Dosage (%)

0 1 2 4 1 2 4

PI 13.68 13.24 12.87 12.09 13.03 12.06 11.63Total thickness (mm)

630 610 605 585 595 590 550

total cost(Rs.)

3,54,75,000

1,50,25,000

1,91,01,300

2,67,23,300

1,19,56,000

1,30,33,500

1,47,24,500

Modulus of Sub-grade E3 (@ 1.4kg/sqcm confinement pressure)

Kg/cm2 2580 3622 3681 4090 3846 4000 5000Mpa 253.01 355.2 360.98 451.11 377.17 392.27 490.34

% Decreas

e in thicknes

s 0 3.17 3.97 7.14 5.56 6.35 12.70%

Savings 0 57.65 46.16 24.67 66.30 63.26 58.49%

increase in E3 value 0.00 40.39 42.67 58.53 49.07 55.04 93.80

45

0 0.5 1 1.5 2 2.5 3 3.5 4 4.50

2

4

6

8

10

12

14

% Dosage

% D

ecr

ease

in

th

ickn

ess

RBI-

81

SF

The above graph1 shows % decrease in Thickness verses % Dosage of stabilizer

0 0.5 1 1.5 2 2.5 3 3.5 4 4.50.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

% Dosage

% in

cre

ase

in E

3

SF

RBI-

81

The above graph2 shows % increase in modulus value verses % Dosage of stabilizer

46

0 0.5 1 1.5 2 2.5 3 3.5 4 4.50

10

20

30

40

50

60

70

% Dosage

% S

avin

gs

SF

RBI-81

The above graph3 shows % Savings in cost verses % Dosage of stabilizer

CHAPTER-5

DISCUSSION AND CONCLUSION

5.1 Discussion

The study of soil characteristics and the analysis is very important aspect in the design of

the pavement which involves several complexities due to variable factors. This study is aimed at

evaluating the strength properties of the given soils by stabilization using the given stabilizers

and the results are compared.

Plastic index was reduced when % Stabilizer dosage increased. But % decrease was

greater when Silica Fume was used.

Shear strength was also increased when specimen was subjected to Triaxial test with

different confinement pressure with different dosage. But the specimen with 4% RBI-81

showed shear failure at a confinement pressure of 0.7kg/cm2. But with same % of Silica

47

fume as stabilizer, bulging was observed .So from above point of view infra that with

increase in RBI dosage the stabilized layer shows rigid behavior.

Young’s modulus of stabilized soil also increased with increase in % stabilizer dosage to

about 60% and 90% with RBI-81 and Silica Fume as stabilizer.

All the above observations are based on 3days moist curing.

Design of pavement as per IRC-37 based on CBR showed required thickness of

630mm(BC=40mm,DBM=140mm,Base=250mm,Sub-Base=200mm), and cost involved

was around 3.6cr for 4-lane dual carriage way with 4mt median and 2mt paved shoulder

on either side, as per scheduled rate for materials.

When design was compared with IRC-37 Annexure method the thickness of pavement

was reduced by replacing all the layers with stabilized locally available soil, here the

Modulus of elasticity was taken at confining pressure of 1.4kg/sqcm.

From above design with different stabilizer shows that, when the Silica Fume as

stabilizer with 4% dosage at confining pressure of 1.4kg/ sqcm the thickness was

reduced by around49% with bulging . Similarly when RBI-81 as stabilizer the thickness

was reduced around 28% with shear failure.

Comparing with the cost estimated it showed around 46% and 62% savings with RBI-81

and Silica Fume as stabilizer with 2% dosage.

5.2 Conclusion

The conclusion given below are based on 3 days moist curing and testing for Sandy

clayey(SC) type of soil which was classified based on IS-Classification. And rates as

per scheduled rate6.

The above results when compared shows Silica Fume can be used as stabilizer.

When Silica fume as stabilizer comparing with RBI-81 with 2 and 4%dosage

shows around 15 and 30 % savings compared with conventional method design.

48

As test are need to be carried out for more soil samples and allowing for moist

curing for more number of days and observing the failure characteristic which

type stabilizer to use can be suggested .

As the above design method i.e. (IRC-37 Annexure) pavement thickness

obtained need be studied with trial stretch, observations are need to be made.

5.3 Scope for future studies

Since Silica fume is a byproduct it may be harmful for environment, using such

materials for construction in different forms at different level may reduce the harmful

effect in future.

Since Silica Fume as Cementitious property it can be used in highway construction.

Studies have be carried out for different types of pavement with waste materials like

Silica Fume, as stabilizer or partially replacing cement in rigid pavement or with

silica fume alone.

References

1. Highway Engineering by S.K.Khanna and C.E.G. Justo.

2. Highway materials and pavement testing by S.K.Khanna - C.E.G. Justo-

A.Veeraragavan.

3. Geotechnical Engineering by T.N.Ramamurthy and T.G. Sitharam.

4. Highway Engineering by Dr.L.R.Kadyali and Dr.N.B.Lal.

5. http://www.icjonline.com/views/2002_07_Singh.pdf ,

http://greenbuildings.santa-monica.org/appendices/apamaterials.html

6. www.chronicindia.org suppliers in Silica Fumes.

7. Civil Engineering Materials by Handoo, Mahajan Kaila.

8. IRC-37 Guidelines for design of flexible pavements by Indian Road

Congress

49

http://www.chronicindia.org/

http://greenbuildings.santa-monica.org/appendices/apamaterials.html

Annexure 1

Shows Triaxial compression test (Stress verses Strain) Graphs with different %dosage at 0.7, 1.4

and 2.1kg/sqcm confinement pressure.

1. Triaxial test result Graphs for Native Red Soil (RS) at 0.7kg/sqcm confinement pressure.

50

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-03 8.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

Strain

Shea

r st

ress

(kg/

cm2)

E=2430 Kg/sqcm

2. Triaxial test result Graphs for Native Red Soil (RS) at 1.4 kg/sqcm confinement pressure.

51

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00St

ress

E=2580.64 Kg/sqcm

3. Triaxial test result Graphs for RS +1% RBI-81 at 0.7 kg/sqcm confinement pressure.

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-030.00

1.00

2.00

3.00

4.00

5.00

6.00

Strain

Shea

r Str

ess(

kg/s

qcm

)

E=3500 Kg/ sq cm


52

0.00E+00 5.00E-04 1.00E-03 1.50E-03 2.00E-03 2.50E-03 3.00E-03 3.50E-030.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

Strain

She

ar s

tre

ss (

kg/s

qcn

)

E=3622Kg/sqcm


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-030.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

E=3689.17 Kg/sqcm


53

0.00E+00 5.00E-04 1.00E-03 1.50E-03 2.00E-03 2.50E-03 3.00E-03 3.50E-03 4.00E-03 4.50E-030.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

Strain

Shea

r St

ress

(Kg/

sqcm

)

E=3600 Kg/sqcm


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

Strain

Shea

r St

ress

(kg/

sqcm

)

E=3681.12 Kg/sqcm


54

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

Strain

She

ar s

tre

ss(K

g/sq

cm)

E=4090.32 Kg/sqcm


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

Strain

Shea

r St

ress

(kg/

sqcm

)

E=3733.33 Kg/sqcm


55

0.00E+00

5.00E-04

1.00E-03

1.50E-03

2.00E-03

2.50E-03

3.00E-03

3.50E-03

4.00E-03

4.50E-03

5.00E-03

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

Strain

Shea

r St

ress

(Kg/

sqcm

)


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-030.00

5.00

10.00

15.00

20.00

25.00

Strain

Shea

r St

ress

(kg/

sqcm

)

E=4600.90 Kg/sqcm

12. Triaxial test result Graphs for RS +1% SF at 0.7 kg/sqcm confinement pressure.

56

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

Strain

Shea

r St

ress

(Kg/

sqcm

)

E=3689.46 Kg/cm2


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-03 8.00E-03 9.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

E=3846.67Kg/cm2


57

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-030.00

5.00

10.00

15.00

20.00

25.00

Strain

Shea

r St

ress

(kg/

sqcm

)

E=4000.87Kg/cm2


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-030.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Strain

Shea

r Str

ess(

Kg/s

qcm

)

E=3816.81Kg/sqcm


58

-5.00E-04

9.97E-18

5.00E-04

1.00E-03

1.50E-03

2.00E-03

2.50E-03

3.00E-03

3.50E-03

4.00E-03

4.50E-03

5.00E-03

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

Strain

Shea

r st

ress

(kg/

sqcm

)

E=4000 Kg/sqcm


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

Strain

Shea

r St

ress

(kg/

sqcm

)

E=4966.57 Kg/sqcm


59

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-030.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

Strain

Shea

r St

ress

(Kg/

sqcm

)

E=4333.33 Kg/sqcm


0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-030.00

5.00

10.00

15.00

20.00

25.00

Strain

Shea

r str

ess(

kg/s

qcm

)

E=5000 Kg/sqcm


60

0.00E+00 1.00E-03 2.00E-03 3.00E-03 4.00E-03 5.00E-03 6.00E-03 7.00E-03 8.00E-03 9.00E-030.00

5.00

10.00

15.00

20.00

25.00

Strain

Shea

r Str

ess(

kg/s

qcm

)

E=5125.18 Kg/ sqcm

61

STUDY OF SOIL PROPERTIES WITH SILICA FUME AS STABLIZER AND COMPARING THE SAME WITH RBI-81 AND COST...

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Transcript of STUDY OF SOIL PROPERTIES WITH SILICA FUME AS STABLIZER AND COMPARING THE SAME WITH RBI-81 AND COST...