effect of quick lime on the behavior of soil

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A project report

On

EFFECT OF QUICK LIME ON THE BEHAVIOUR OF SOIL

Submitted in partial fulfillment of the requirement for the award of degree of

BACHELOR OF TECHNOLOGY

in

CIVIL ENGINEERING

by

C.VINILA 097B1A0108

M.RAMA DEVI 097B1A0133

P.GREESHMA 097B1A0138

Under the guidance of

Mr. M. NAVIN (M. Tech)

Assistant Professor in Department of Civil Engineering.

SITECH, Chevella.



DEPARTMENT OF CIVIL ENGINEERING

SAGAR INSTITUTE OF TECHNOLOGY (SITECH)

(Affiliated to Jawaharlal Nehru Technological University, Hyderabad)

DEPARTMENT OF CIVIL ENGINEERING

CERTIFICATE

This is to certify that the project entitled “EFFECT OF QUICK LIME ON THE BEHAVIOUR OF

SOIL” is being submitted by

C.VINILA 097B1A0108



in partial fulfillment of the requirements for the award of BACHELOR OF TECHNOLOGY

to JNTU, Hyderabad. This record is a bonafide work carried out by them under my guidance

and supervision. The result embodied in this project report has not been submitted to any other

university or institute for the award of any degree of diploma.

Guide Head, Civil Engineering Department

(M. Navin, Asst prof) (Y. Sanjeeva Kumar)

Principal

(V.V.V.Satyanarayana)



ACKNOWLEDGEMENT

I would like to express my gratitude to all the people behind the screen who helped me to transform an idea

into a real application. I would like to express my heart-felt gratitude to my parents without whom I would

not have been privileged to achieve and fulfill my dreams. I am grateful to our principal, Mr.

V.V.S.SATYANARAYANA who most ably run the institution and has had the major hand in enabling meto do my project. I profoundly thank Mr. Y. SANJEEV KUMAR Head of the Department of CIVIL

Engineering who has been an excellent guide and also a great source of inspiration to my work. I would like

to thank my internal guide Mr. M.NAVIN ( Asst prof ) for his technical guide, constant encouragement and

support in carrying out my project at college. The satisfaction and euphoria that accompany the successful

completion of the task would be great but incomplete without the mention of the people who made it

possible with their constant guidance and encouragement crowns all the efforts with success. In this context,

I would like thank all the other staff members, both teaching and non-teaching, who have extended their

timely help and ease my task.

C.VINILA 097B1A0108





CONTENTS

INTRODUCTION

LITERATURE SURVEY

EXPERIMENTAL ANALYSIS

RESULTSCONCLUSIONS

REFERENCES

INTRODUCTION

Earth has been used as a building material for years. From ancient times to the present day, it's been used to

build everything

from modest shelters to elaborate temples using a wide variety of techniques. Earthen construction has

witnessed a renaissance

in recent years due largely to economic & environmental concerns. Availability, low cost & eco-friendly

nature of soil as a building material makes it an attractive alternative to conventional building methods.

1.1

EARTH - AN ARCHITECTURAL TRADITION

A Very Ancient Building Tradition

The distant origins of the compressed earth block technique can be traced back thousands of years to the

moulded sun-dried earth brick, better known by the name of "adobe". The sun-dried earth brick marks

historical stages in the evolution of the human race. Linked to the emergence of an architectural tradition

and urban settlements which laid the foundations for the urban revolution, with sun-dried earth bricks came

social and economic organisation, the production of building materials and the use of these for building.

This use, which was to radiate further and further afield, liberated man from rudimentary materials and

techniques of limited architectural potential. The way was now open for a durable and monumental form of architecture, in Mesopotamia (present-day Iraq), in the Indus valley (India), along the banks of the Huanghe

(China) and the Nile (Egypt), the main cradles of civilisation.

An Inevitable Historical Progression

The recent progression towards the compressed earth block is a logical extension of the benefits of the

industrial revolution which brought the significant development of the fired brick. With the need to improve

the quality of materials and the durability of buildings, linked to better productivity, came compaction. CEB

press technology is inherited directly from the ceramics or calcium silicate industries. The need to save

energy and notably that used for firing in times of shortage (after the second world war, and later during the

petrol crisis), accelerated the development of the compressed earth block and encouraged a broadening of its

architectural application in regions faced by high energy costs.



1.2 NATURE OF THE PROBLEM

When building with earth, one is confronted with two basic options.

- The type of soil available on site dictates the building system.

- The building system, having been predetermined, dictates the use of a particular type of soil.

In the first instance, architecture, in other words the design takes account of the site context and determines

the building systems which will ensure the durability of the buildings; architectural choices act as a

"stabilizer". This is the first approach to be preferred and used.

In the second instance, it is the manufacturing technique, often alien to the site, which ensures the durability

of the materials used, more or less independently of the building systems; the process and the addition of

material(s) act as a “stabilizer”.

In this work, we deal with the second instance, i.e. the improvement of the soil by adding stabilizers

(materials). Every kind of soil, however, has a corresponding suitable stabilizer. There are more than a

hundred products in use today for stabilization. These stabilizers can be used both in the body of the walls

and in their outer "skin": in renders, for example. Stabilization has been practiced for a very long time, but

despite this, it is still not an exact science and to date no "miracle" stabilizer is known among the multitude

of products available, some of which should not even be considered, either because of their inefficiency, or

because they are prohibitively expensive.

1.3 OBJECTIVES

Only two characteristics of the soil itself can be treated: its structure and its texture.

There are three ways of treating the structure and the texture of a soil:

reducing the volume of voids between the particles, i.e. affecting its porosity;

blocking up the voids which can't be eliminated, i.e. affecting its permeability;

improving the links binding the particles together, i.e. affecting its mechanical strength.

The main objectives being pursued are:

obtaining better mechanical performances: increasing dry and wet compressive strength;

reducing porosity and variations in volume: swelling and shrinking with moisture content

variations;

improving the ability to withstand weathering by wind and rain: reducing surface abrasion

and

increased waterproofing.

1.4 HOW LIME WORKSMixing a limited dosage of unslaked lime into damp soil creates both “immediate” and “medium term”

effects.

Immediate Effect: Soil Improvement

Drying:When the unslaked lime is mixed with damp soil there is an immediate reaction whereby a lot of heat is

generated (exothermic hydration reaction). The result is a reduction of the natural water content of the soil

by hydration and evaporation. This water loss is further increased by the aeration of the soil during the

mixing process. Depending on the weather conditions, the water content can fall by 2 to 3% per percentage

of added lime.Flocculation:



The addition of lime affects the electrostatic field between the clay particles. As a result, they assume a

granular structure. In geotechnical terms, these two phenomena are expressed as:A reduction in the plasticity index:

The soil suddenly switches from being plastic (yielding and sticky) to being crumbly (stiff and grainy). In

the latter condition it is easier to excavate, load, discharge, compact, and level.

An improvement in the compaction properties of the soil:The maximum dry density drops, while the optimal water content rises, so that the soil moves into a

humidity range that can be easily compacted. This effect is clearly advantageous when used on soils with

high water content, which is common in our areas. A treatment with quicklime therefore makes it possible to

transform a sticky plastic soil, which is difficult to compact, into a stiff, easily handled material. After

compacting, the soil has excellent load-bearing properties.

Improvement of bearing capacity:

In most cases, two hours after treatment, the CBR (California Bearing Ratio) of a treated soil is between 4

and 10 times higher than that of an untreated soil. This reaction greatly relieves on-site transportation

difficulties.

Medium Term Effects: Soil Stabilization

When lime comes into contact with a substance containing soluble silicates and aluminates (such as clay and

silt), it forms hydrated calcium aluminates and calcium silicates. As with cement, this gives rise to a true

bond upon crystallization. Called a pozzolanic reaction, this bonding process brings about improved

resistance to frost and a distinct increase in the soil’s compressive strength and CBR.

In general, in non-winter conditions, the soil develops sufficient strength after three to six months. A slow

curing process during road construction is a marked advantage, as it allows greater flexibility when workingwith the treated soil.

The long-term hardening facilitates the design of foundations for industrial platforms. The stabilizing effect

gives load-bearing qualities to the treated soil.

LITERATURE REVEIW

This chapter contains a discussion of the mechanisms of modification and stabilization and the Improvement

in soil properties that may be achieved. The available literature on lime modification and stabilization was

reviewed, and the pertinent information and similar studies are presented. The Production of lime and its

chemistry are reviewed. The theoretical mechanisms and general reactions for soil-lime mixtures are

reviewed.

2.1 SOIL STRUCTURE

The clay particles in the soil structure are arranged in sheet- like structures composed of silica tetrahedra and

alumina octahedra. The sheets form many different combinations but there are three main types of

formations. The first is kaolinite, which consists of alternating silica and alumina sheets bonded together.

This form of clay structure is very stable and does not swell appreciably when wetted. The next form is

montmorillonite, which is composed of two layers of silica and one alumina sheet creating a weak bond



between the layers. This weak bonding between the layers allows water and other cations to enter between

the layers, resulting in swelling in the clay particle. The last type is illite, which is very similar to

montmorillonite, but has potassium ions between each layer, which help bond the layers together. Interlayer

bonding in illite is therefore stronger than for montmorillonite but weaker than kaolinite (5). Clay particles

are small in size and have a large surface to mass ratio, resulting in a larger surface area available for

interaction with water and cations (5). The clay particles have negatively charged surfaces that attract

cations and polar molecules, including water, forming a bound water layer around the negatively charged

clay particles (1). The amount of water surrounding the clay particles is related to the amount of water that is

available for the clay particle to take in and release. This moisture change around the clay particles causes

expansion and swelling pressures within clays that are confined.

2.2 STABILIZATION AND MODIFICATION

The process of reducing plasticity and improving the texture of a soil is called soil modification. Monovalent

cations such as sodium and potassium are commonly found in expansive clay soil and these cations can be

exchanged with cations of higher valences, such as calcium, which are found in lime, fly ash and Portland

cement. This ion exchange process takes place quite rapidly, often within a few hours. The calcium cationsreplace the sodium cations around the clay particle’s decreasing the size of the bound water layer and

enabling the clay particle to flocculate. The flocculation creates a reduction in plasticity, an increase in shear

strength of the clay soil and an improvement in texture from a cohesive material to a more granular, sand-

like soil (3). The change in the structure causes a decrease in the moisture sensitivity and increases the

workability and constructability of the soil. Soil stabilization includes all the effects of modification with an

additional long-term strength gain. Soil conditions and mineralogical properties have a greater role for soil

stabilization than modification. The magnitude of soil stabilization is usually measured by the increase in

strength.

2.3 METHODS OF STABILISATION

There are numerous methods by which soils can be stabilized; however, all methods fall into two broad

categories. They are

1. Mechanical stabilization.

2. Chemical admixture stabilization.

Some stabilization techniques use a combination of these two methods. Mechanical stabilization relies on

physical processes to stabilize the soil, either altering the physical composition of the soil (soil blending) or

placing a barrier in or on the soil to obtain the desired effect (such as establishing a sod cover to prevent dust

generation). Chemical stabilization relies on the use of an admixture to alter the chemical properties of the

soil to achieve the desired effect (such as using lime to reduce a soil’s plasticity).

2.4 LIME STABILISATION

2.4.1 Lime Manufacturing

The main ingredient in lime commonly used in construction today is a compound of calcium and oxygen

called calcium oxide, CaO. This type of lime is called high calcium quicklime. Dolomitic lime, which

contains significant portions of magnesium oxide (MgO), is also available. For both compounds, the lime is

formed by calcining crushed limestone (predominantly CaCO3) at a temperature of 982°C. In order to

maintain the purity of the end lime product, tests are conducted on the limestone before calcining begins to

ensure there are not any major contaminants in the basic limestone chemistry (WWW-National Lime



Association, Jan 2000). The high temperature boils off the carbon dioxide, as shown in the following

reaction:

CaCO3 + Heat CaO + CO2 (2.1)

Commercially produced lime is sold from the kilns as either quicklime or hydrated lime. Quicklime is the

calcium oxide (CaO) produced from calcining. Hydrated lime is quicklime that has been slaked (mixed with

a small amount of water). Hydrated lime is formed by the following reaction:

CaO + H2O Ca(OH)2 + Heat (2.2)

This reaction happens quickly and produces a significant amount of heat. After slaking, the lime becomes a

very fine powder. From their chemical formulas and the atomic weights for the elements found in Table 1, it

can be seen that the molecular weight of quicklime is 56.08, and the molecular weight of hydrated lime is

74.09. From these weights, the ratio of hydrated to quicklime required to provide the same amount of

calcium is 1.321. A ratio of 1.3 (hydrated to quick) is commonly used in design and construction (Little,

1995).

Table 2.1:

Molecular Weights

Hydrogen (H) 1.00794

Oxygen (O) 15.9994

Calcium (Ca) 40.078

Calcium Oxide (CaO) 56.077

Calcium Hydroxide (Ca(OH)2) 74.093

Both forms of lime need to be protected from the atmosphere until being mixed with the soil. Quicklime will

react with atmospheric moisture and both forms of lime will react with carbon dioxide in the air to reform

calcium carbonate. This carbonation is a reversal of the calcining reaction. It is a relatively slow reaction,

but, once carbonated, lime is rendered ineffective for use in construction (Little 1995).

2.4.2 Lime-Clay Interactions

Lime mixed with soil causes immediate changes in the structure and stability of the clay matrix and in many

types of clay it produces long term strength gains. The immediate changes in structure and moisture stability

are often called modification, while the strength gain is often called stabilization. These changes in soil

properties will be reviewed separately for clarity. Soil modification is a function of the mineralogy and

structure of fine grained soils. Clay structures are made up of long sheets of silica tetrahedra and aluminium

octahedra (also called gibbsite). These structures are shown graphically in Figure 2.4.1. Kaolinite consists of

alternating sheets of silica and alumina held together by hydrogen bonding. Illite is formed by an alumina

sheet sandwiched between two silica sheets and illite layers are bonded together by potassium ions.

Montmorillonite, a type of smectite mineral, also consists of an alumina sheet between two silica sheets.

However, montmorillonite layers are held together by available cations and potassium is not present (Das2000).



Figure 2.1: Structures of common minerals

Each of these clay minerals has a net negative charge at the surface. Due to the net negative charge at thesurface, cations and polar molecules (usually water) are attracted to the surface of the clay mineral. These

minerals accumulate a layer of cations and water molecules around the particle called a diffused water layer.

In a smectite, this diffused water layer can be several times thicker than the clay particle. Modification

involves decreasing the moisture sensitivity and plasticity of a soil. Lime achieves this primarily through

cation exchange and a resulting flocculation- agglomeration of the clay particles. In a natural state, clay

particles have a diffused water layer surrounding them which tends to orient the particles in a parallel

fashion, as shown in Figure 2.2(a). When lime is mixed with the soil in the presence of water, calcium

cations in solution do two things: replace cations at the clay surface and raise the pH of the mixture. Where a

cation will tend to replace one to its left. According to this series, calcium will replace the cations present in

most clays. Little (1987) states, as an example, that given equal concentrations of cations in the pore water,

there will be 17.5 times more calcium ions than sodium ions at the clay surface.

The calcium ions that result from adding lime replace many of the cations at the clay surface and this helps

to reduce and stabilize the diffuse water layer. Raising the pH of the mixture also increases the cation

exchange capacity (SOTAR, 1987), encouraging further replacement of cations by the calcium. The

reduction in the diffuse water layer allows the particles to align in a more edge-to-face alignment as shown

in Figure 2.2(b).This new configuration increases the friction angle and shear strength of the soil and it

improves the workability of the soil by decreasing plasticity and making it more friable (Hausman 1990).



Figure 2.2: Clay particles in parallel and edge-to-face alignment (Little, 1996)

Although there is an immediate strength improvement due to textural changes, stabilization involves the

formation of cementitious compounds within the clay structure over time. The compounds are formed by

available calcium and the alumina and silica oxides dissolved from the clay structure at a high pH. The

components react to form calcium silicate hydrates and calcium alumina hydrates, cementitious products

that tend to form bonds between the clay particles. This process is dependent on ample free lime, available

clay minerals, and conducive environmental conditions. Strength can continue to increase for several months

or even years under the proper conditions (Little 1995).

2.5 Other Soil-Lime Characteristics

Previous studies have identified many trends and general characteristics of changes in soil properties due to

the addition of lime. The universal effect of mixing lime with plastic soils is the reduction in plasticity of a

soil when mixed with lime. Little (1995) states that lime treatment causes a substantial reduction in the

plasticity of a soil and the soil often will become non-plastic. Laguros (1965) found that the plasticity index

of a soil was reduced from 47 to 15 with the addition of 6% hydrated lime. Jan and Walker (1963) noted that

the incremental reduction in plasticity decreases as the lime content increases. Others have found that after

approximately 2 to 4% hydrated lime is added, the additional effect on the plasticity of the soil is minimal

(Puppala, Mohammad, and Allen 1996; also Sweeney, Wong, and Fredlund 1988). Basma and Tuncer (1991) tested the plasticity of lime treated soils at cure times of 1 hour to 28 days and found that cure time

had little effect on the plasticity of a lime treated soil.Lime also decreases the apparent amount of fines in a

soil by causing flocculation and agglomeration of the clay particles (Little 1995). This results in an increase



in the percentage of sand and silt size particles as measured by standard grain size distribution methods

(Basma and Tuncer 1991). Lime can also be used to reduce the dry gradation of a soil if there are significant

amounts of large clay clods (Lime Stabilization Construction Manual 1991).Lime also tends to reduce the

swell potential of fine grained soils (Kennedy et al 1987). There is not agreement as to the time effects on

swell potential. Sweeney, Wong, and Fredlund (1988) found that swell characteristics of a lime treated soil

were unaffected by the cure time before testing, while Basma and Tuncer (1991) found that increased cure

time tended to decrease the swell potential. Moisture content plays an important role in the swell potential of

a lime treated soil; soils with a moisture content below optimum show a much greater swell potential than

soils with a moisture content above optimum (Sweeney et al 1988).

The amount of fines and types of clay minerals affects the effectiveness of the lime in stabilizing a soil and

causing long term strength gain. Ford, Moore, and Hajek (1982) used x-ray diffraction, thermogravimetric

analysis, and a scanning electron microscope to examine the structural changes on a particle level to a

Southeastern clay soil when lime is added. They found that soils with a significant amount of

montmorillonite developed almost no increase in unconfined compressive strength. They concluded that

most of the lime was used to break down the montmorillonite and the montmorillonite also had too great of

a surface area for the cementitious compounds to significantly affect the strength.

There appear to be other criteria that affect the ability of lime to stabilize a soil.Moore and Jones (1971),

using data from Illinois soils, found that surface area has an inverse correlation to the unconfined

compressive strength of a lime stabilized soil, but their data suggest only a moderate correlation. They found

that available silica appears to be more important to long-term strength gain than is available alumina. They

also found that an inverse correlation exists between extractable iron in soils and their unconfined

compressive strength after being stabilized with lime. Epps, Dunlap, Gallaway, and Currin (1971) reviewed

several criteria for stabilization and found that, in general, a soil should have a clay content of at least 7%

and a plasticity index of at least 10 to be considered a candidate for stabilization using lime. They also foundthat low pH, high organic content, and high sulfate content are prohibiting factors in stabilizing soils with

lime. Lime tends to increase the strength of many soils; time and lime content appear to have a great effect

on the amount of strength gain that occurs (Tuncer and Basma 1991).

Ford, Moore, and Hajek (1982) also found that for a lime treated soil compacted at two different moisture

contents, the soil developed a minimal strength gain when compacted dry of optimum, while the soil had an

unconfined compressive strength gain of over 344 KPa when compacted at optimum moisture. This

indicates that moisture content at mixing can affect the strength gained from lime treatment. Pulverization of

the native soil has an effect on the ability of the lime to be effectively mixed with the soil. Petry andWohlgemuth (1988) tested a fine-grained soil at 60%, 80%, and 100% of the dried soil passing a 4.75 mm

sieve. They found that after a 28 day cure, the unconfined strength of the coarsest sample was 172 KPa,

while the finest gradation had an unconfined compressive strength of 758 KPa.

Adding lime to some soils tends to reduce the maximum dry density and increase the optimum moisture

(Wang et al 1963), but there are other soils that exhibit little change. Lockett and Moore (1982) found that,

for soils in the south-eastern United States, lime modification of clays dominated by montmorillonite

increases the optimum moisture by as much as 20 points over the native soil. However, Tuncer and Basma

(1991) found that there was no significant change in the maximum dry density and optimum moisture of a

soil after adding lime. The change in Proctor values due to addition of lime appears to be different for each

soil. However, longer mellowing of lime treated soils tends to reduce the maximum dry density in most soils

(Sweeney et al 1988). Compaction procedure appears to affect the strength of lime treated soils. Dry density

and moisture control during construction are essential to obtaining adequate strengths (Jan and Walker 1963)



and increasing compaction from standard to modified Proctor methods can double the strength of a soil

(Kennedy et al 1987). Increased rolling of a lime treated soil in the field has been found to increase the

strength of a soil (Jan and Walker 1963), but over compaction can actually break up the soil and make it

weak (Sweeney, Wong, and Fredlund 1988). Although some studies have been done on the effectiveness of

field operations, there is great variation in the properties measured using field samples and often only a

moderate correlation to laboratory results. Stewart, Fletcher and Chu (1971), using soils from South

Carolina, found that cores taken from a constructed base showed unconfined compressive strengths

comparable to or greater than lab strengths. They did, however, have great difficulty in obtaining field cores

that could be used in testing. They also found a wide variation in lime contents in the field mixed soil. Little

(1995) also found great variations in the stiffness of in-situ field lime treated and compacted soils.

McDowell (1966) found that lab determined strengths underestimated the actual strength of field lime

treated soils.

Hoover (1965) compared strengths of lime treated soils mixed and compacted in the lab to the strengths of

soils mixed in the field and compacted in the lab. He found that field mixed samples had an unconfined

compressive strength of 724 KPa, while lab mixed soils had an unconfined compressive strength of 1585

KPa. He also found that field compaction of lime treated soils yielded dry density values above 100% of standard Proctor for the lime treated soil.

Much of the preceding discussion about strength was intended to show the tendencies of lime to affect

strength and the possible variables that can affect strength in a soil-lime mixture.

2.6 Soil classification tables:

i.



ii.



Guide for selecting a stabilizing additive:

METHODOLOGY

3.1 METHODOLOGY FOLLOWED

Collection of Soil

Laboratory Analysis

Soil + Quick Li

Laboratory Ana



EXPERIMENTAL ANALYSIS

Procedure

Materials used

1) Native soil.

2) Quick lime.

The soil sample collected should be oven dried for 24 hrs before testing it’s properties.

The first and foremost test that is conducted on soil is “sedimentation jar test ”.

It’s a simple field test used to identify the type of soil.



3.1 Sedimentation jar test:

→Pass some of the soil through a sieve with 4.75mm mesh.

→Take straight sided clear glass jar and it one-third with the sieved soil.

→Add water until the jar is full. Shake the jar for one or two minutes.

→ Place the jar on a flat surface.

→After about half an hour the soil will have settled, have a look at it and then shake it up again well.

→ Leave the jar to settle overnight.

→Sometimes it helps to add a little salt (1 tea spoon) to the jar because this helps to separate clay from sand.

→Hopefully the soil will separate out in layers.

3.2 Grain Size analysis:

(As per IS: 2720-part 2-1975)

OBJECTIVE

(a). Select sieves as per I.S specifications and perform sieving.

(b). Obtain percentage of soil retained on each sieve.

(c). Draw graph between log grain size of soil and % finer .

SCOPE OF EXPERIMENT

The grain size analysis is widely used in classification of soils. The data obtained from grain sizedistribution curves is used in the design of filters for earth dams and to determine suitability of soil for road

construction, air field etc. Information obtained from grain size analysis can be used to predict soil water

movement although permeability tests are more generally used.

Equipment:

Stack of Sieves including pan and cover

Balance (with accuracy to 0.01 g)

Rubber pestle and Mortar ( for crushing the soil if lumped or conglomerated) Mechanical sieve shaker

Oven



Test procedure:

→ Take a representative oven dried sample of soil that weighs about 500 g. (this is normally used for soil

samples the greatest

Particle size of which is 4.75 mm)

Notice: you may wish to take more than 500 g of soil.

→ If soil particles are lumped or conglomerated crush the lumped portion using the pestle and mortar.

→ Determine the mass of sample accurately.

→ Prepare a stack of sieves. Sieves having larger opening sizes (i.e. lower numbers) are placed above the

ones having smaller

Opening sizes (i.e. higher numbers). The very last sieve is 75µ and a pan is placed under it to collect the

portion

Of soil passing 75µ sieve.

→ Make sure sieves are clean, if many soil particles are stuck in the openings try to poke them out using

brush.

→ Weigh all sieves and the pan separately.

→Pour the soil from step 3 into the stack of sieves from the top and place the cover, put the stack in the

sieve shaker and fix the

Clamps adjust the time on 3 to 5 minutes and get the shaker going.

→Stop the sieve shaker and measure the mass of retained soil on each sieve.

3.3 Determination of liquid limits (cone penetrometer):

(As per IS: 2720-part 5-1970)

SCOPE OF EXPERIMENT:

This method describes the procedures for the determination of the Liquid Limit of soils and granular

materials.

DEFINITION

The Liquid Limit is the moisture content at which the soil passes from the plastic to the liquid state as

determined by the Liquid

Limit test.

Equipment:

Penetrometer, any suitable penetrometer which permits the cone assembly to move vertically in its

guide without



appreciable friction and which is capable of indicating the depth of penetration to the nearest 0.1mm.

The sides of the

guide shall be vertical.

Penetration Cone Assembly, a stainless steel cone with a cone angle 30 ± 1°. The conical surfaces

shall be polished. The

total moving mass (of the cone assembly) shall be 80.0 ± 0.1g.

A container approximately 55mm in diameter and 40mm deep with a rim parallel to the flat base.

4. Mixing bowl, approximately 150mm diameter.

5. Wash bottle or beaker containing distilled or de-ionised water.

6. Spatula.

PROCEDURE

→Take representative soil sample of approximately 120gms passing through 425 micron IS sieve and mix

thoroughly with

distilled water in the evaporating dish to a uniform paste.

→The paste shall have a consistency that will require 30 to 35 drops of the cup to cause the required closure

of the standard

groove.

→The wet soil paste shall then be transferred to the cylindrical trough of the cone penetrometer and levelled

to the top of the

trough.

→The penetrometer scale shall then be adjusted to zero, and the vertical rod released so that cone is allowed

to penetrate into

the soil paste under its weight.

→The penetration shall be noted after 30 sec from the release of cone.

→If penetration is less than 20 mm, the wet soil from trough shall be taken out and more water added and

thoroughly mixed.

→The test shall then be repeated till a penetration between 20 mm to 30 mm is obtained.

→The exact depth of penetration between these two values obtained during the test shall be noted.

→The moisture content of the corresponding soil paste shall be determined in accordance with IS procedure.

The liquid limit of soil which corresponds to the moisture content of a paste which would give 25

mm of penetration of the cone shall be determined from the following formula:

WL=Wα+0.01(25-α)(Wα+15)

Where,

WL=liquid limit of soil,



Wα =moisture content corresponding to penetration,

α=depth of penetration of cone in mm.

3.4 Determination of Plastic limit:

(As per IS: 2720-part 2-1975)

SCOPE OF THE EXPERIMENT:

This method describes the procedures for the determination of the Liquid Limit of soils.

DEFINATION

Plastic limit is defined as minimum water content at which soil remains in plastic state.

Equipment

Porcelain evaporating dish.

Flat glass plate 10mm thick and about 45cm square or longer.

Spatula flexible with the blade about 8cm long and 2cm in wide.

Airtight containers.

Balance of capacity 500grams and sensitivity 0. 01gram.

Rod 3mm in diameter and about 10cm long.

PROCEDURE

→Take representative soil sample of approximately 20g from the portion of the material passing 425 micron

IS sieve and mix thoroughly with distilled water in an evaporating dish till the soil mass becomes plastic

enough to be easily moulded with fingers.

→In the case of clayey soils, leave the soil mass to stand for 24 hours to ensure uniform distribution of

moisture through out the Soil.

→Form a ball with about 8 grams of this soil mass and roll between the fingers and the glass plate with justsufficient pressure to roll the mass into a thread of uniform diameter throughout its length.

→The rate of rolling shall be between 80 and 90 strokes/minute counting the stroke as one complete motion

of the hand forward and back to the starting position again.

→Continue the rolling till the thread crumbles exactly at 3mm diameter.

→If the soil thread doesn’t crumble exactly at 3mm knead the soil together to a uniform mass and roll it

again.

→Continue this process of alternate rolling and kneading until the thread crumbles under the pressureexactly at 3mm diameter.

→Collect the pieces of crumbled soil thread in an airtight container and determine its moisture content.



→Determine the plastic limit for at least two points of the soil passing 425 micron IS Sieve.

PRECAUTIONS:

→At no time shall an attempt be made to produce failure at exactly 3mm diameter by allowing the thread

to reach 3mm then

reducing the rate of rolling or pressure or both and continuing the rolling without further deformation untilthe thread falls

apart.

3.5 Determination of plasticity index:

DEFINITION

The plasticity Index is defined as the numerical difference between its Liquid Limit and Plastic Limit.

REPORT

Plasticity Index = Liquid Limit - Plastic Limit.

PRECAUTIONS:

→ In the case of sandy soils plastic limit should be determined first.

→When plastic limit cannot be determined the Plasticity Index should be reported as NP (Non-Plastic).

→When the plastic limit is equal to or greater than liquid limit, the plasticity index shall be reported as zero.

3.6 Determination of water content-dry density relation using light compaction:

(As per IS: 2720-part 7-1983)

SCOPE OF THE EXPERIMENT

This method describes the procedure to find out the optimum moisture content and dry density from a soilsample compacted as per standard proctor test.

Equipment:

Standard proctor method with collor and base

Standard rammer of 2.59kg wt

IS sieve No-475

Balance

Oven

Measuring cylinder

PROCEDURE:



→The wt of the empty mould is determined. Assemble the base and collor and apply a thin coat of oil

inside.

→2.5kg of soil passing through sieve IS 4.75 mm was weighed into a tray and spread it.

→Known quantity of water was added and soil was mixed thoroughly.

→moist soil was placed in the mould in 3 layers and each layer was compacted with 25 blows of the rammer

falling through

30 cm. Blows were spread uniformly over the entire surface of the soil layer before the next one is spread

for proper bend.

→Final compacted soil was extended slightly beyond the top of the mould into the collor.

→The collor was rotated slightly and move it by pulling it upward slowly.

→Soil was trimmed with a straight edge and levelled at the top of the mould.

→Representative sample of soil was taken from the mould for water content determination after it is takenout from extractor.

→Increase the water content in increments depending upon the rate of increase in the wt of soil and it was

decreased later.

→The procedure is repeated with different water contents.

Note: All the above experiments are repeated with the addition of lime to the soil.

RESULTS:

4.1 Sedimentation jar test:

From the experiment conducted the soil sample contains both silt and clay content.

4.2 Grain size analysis:

From the experiment conducted the results obtained are as follows:

SNO

Sieve size in

mm

wt of soil retained in

gm

cumulative wt retained in

gm

% wt

retained % finer

1 4.75 5.25 5.25 1.05 98.95

2 2 18.33 23.58 4.71 95.29

3 1 24.74 48.32 9.66 90.34

4 0.6 38.52 86.80 17.36 82.64

5 0.425 44.45 131.29 26.25 73.75

6 0.3 65.80 197.09 39.41 60.59

7 0.15 122.95 320.04 64.00 36

8 0.075 76.66 396.70 79.34 20.66

9 pan 102.94 499.64 99.92 0.08



Gravel fraction (>4.75mm) =1.05%

Coarse grained sand (4.75-2.00 mm) =3.66%

Medium grained sand (2.00-0.425 mm) =21.56%

Fine grained sand (0.425-0.075mm) =53.12%

Silt-clay fraction (<0.075 mm) =20.61%

D10=mm

D30=mm

D60=mm

Cu=D60/D10

=

Cc= (D30)2/D60*D10

=

4.3 Determination of plastic limit:

From the experiment conducted the results obtained are as follows:

For 0% lime:

0

20

40

60

80

100

120

0.01 0.1 1 10

% f i n

e r

Dia of grain,mm

Grain size distribution curve



Plastic limit (PL) =32.28%

For 1% lime:


For 3% lime:


4.5 Determination of liquid limit:

For 0% lime:

Liquid limit (LL) =58.50%

For 1% lime:


For 3% lime:


4.6 Determination of plasticity index:

Plasticity index (PI) =LL-PL

For 0% lim

PI=26.22%

For 1% lime

PI=

For 3% lime

PI=15.44%

4.7 Standard proctor test:

O

Wt of

empty

mould in

gm

Wt of

compacted

soil in gm

Bulk density

of soil in

gm/cc Moisture content in % Dry density in g/cc

5168 6737 1.569 12 1.45168 6825 1.657 16 1.42

5168 6887 1.719 20 1.43

5168 6955 1.787 24 1.44



For 1% lime:

1.32

1.34

1.36

1.38

1.4

1.42

1.44

1.46

0 5 10 15 20 25 30 35 40

D r y u n i t w t , γ d , g m / c c

water content,w,%

compaction curve

5168 6999 1.831 28 1.43

5168 7029 1.861 32 1.4

5168 6995 1.827 36 1.34

O

Wt of empty

mould in gm

Wt of compacted

soil in gm

Bulk density of soil

in gm/cc

Moisture content

in % Dry density in g/cc

5168 6805 1.637 12 1.46

5168 6814 1.646 16 1.415168 6891 1.723 20 1.43

5168 6895 1.727 24 1.39

5168 7060 1.892 28 1.47



For 2% lime:

For 3% lime:

1.38

1.39

1.4

1.41

1.42

1.43

1.44

1.45

1.46

1.47

1.48

1.49

0 5 10 15 20 25 30 35

D r y u n i t w t , γ d , g

m / c c

water content,w,%

compaction curve

5168 7111 1.943 32 1.47

SNO

Wt of empty

mould in gm

Wt of compacted

soil in gm

Bulk density of

soil in gm/cc

Moisture

content in % Dry density in g/cc

1 5168 6777 1.609 12 1.43

2 5168 6766 1.598 16 1.37

3 5168 6886 1.718 20 1.43

4 5168 6858 1.69 24 1.36



Soil has been stabilized using 1%, 2%, 3% lime.

This stabilised soil is used in the preparation of blocks.

1.2

1.25

1.3

1.35

1.4

1.45

0 10 20 30 40 50

D r y d e n s i t y , γ d , g m / c c

water content,w,%

compaction curve

5 5168 6869 1.70 28 1.32

6 5168 6931 1.76 32 1.33

7 5168 6941 1.77 36 1.30

8 5168 6912 1.74 40 1.24



Conclusion:

Stabilized soil is used to prepare blocks, the lime content added is in the following proportion that is

1%, 2%, 3%. But the there’s no bonding in the blocks stabilized using 1% and 2% lime.

We have observed a bonding 2 some extent in the block stabilized using 3% lime, but a large

horizontal crack is noticed in the block.

From this we can say that cementing material like fly ash, cement etc is added to the stabilized soil to

attain a proper bonding between the particles.

effect of quick lime on the behavior of soil

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