Permeability Characteristics ofLime Treated Soils

A Thesisby

Md. Shahidul Islam

Submitted to the Department of

CIVIL ENGINEERING, BANGLADESH UNIVERSITY OF ENGINEERINGAND TECHNOLOGY, DHAKA IN PARTIAL FULFILLMENT FOR THE

REQUIREMENT OF THE DEGREE

OF

MASTER OF ENGINEERING (CIVIL)

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Permeability Characteristics ofLime Treated Soils

A Thesisby

Md. Shahidul IslamApproved as to style and content by

Dr. Eqramul HoqueAssociate ProfessorDepartment of Civil EngineeringSUET, Dhaka

Dr. Syed Fakhrul AmeenProfessorDepartment of Civil EngineeringSUET, Dhaka

~;-~~

Chairman(Supervisor)

$~Member

Dr. Mehedi Ahmed AnsaryAssociate ProfessorDepartment of Civil EngineeringSUET, Dhaka

II

.'

...

ACKNOWLEDG EMENT

The author expresses his profound gratitude and indebtedness to Dr. Eqramul

Hoque, Associate Professor, Department of Civil Engineering, BUET, Dhaka and

supervisor of the project for his keen interest, continuous guidance and supervision of

the thesis work.

The author also wishes to express his sincerest thank and appreciation to Prof.

Dr. Syed Fakhrul Ameen and Associate Prof. Dr. Mehedi Ahmed Ansary for their

thoughtful suggestion and comments and serving as a member of the thesis committee.

The author is grateful to Dr. Md. Abdur Rouf, Professor and Head, Department

of Civil Engineering, BUET for his kind co-operation to conduct the project work.

The author acknowledged to Md. Nasir Uddin Ahmed, Director General,

Department of Fisheries, Bangladesh, Dhaka and Engr. A. K. Barman, Project Director,

Food Assisted Fisheries Sector Rural Development Project, Matshaya Bhaban, Dhaka

for their personal interest in this study. The author also conveys his thanks to

Aquaculture I Assistant Engineer, Department of Fisheries, Bangladesh especially to

Engr. Md. Alimuzzaman Chowdhury and Engr. Firoz Ahmed Sikder for their

inspiration and encourages to complete the work.

The author is also thankful to Md. Habibur Rahman and Mr. Alimuddin of Geo-

technical Engineering laboratory for their continuos assistance during laboratory

testing. Help of Mr. Rafiqul Islam, Mr. Md. Abdul Malek and Mr. Sharafat Ali of Civil

Engineering Department also appreciated .

The author heartily wishes to extent his dedication to his beloved parents andwife, for their love, affections and sacrifices .

111

ABSTRACT

Thc effects of lime content on the permcability of lime- trcated soils were

investigated. Three soils, namely, a fine sand, a rclatively coarse sand and a clay were

collected from diffcrent areas of Bangladesh for thesc purposes. After collecting the

soil-mass from the field, they were dried and cleaned. The clay was made powdered by

using a grinding machine. Lime, in the predetermined proportion, was mixed

thoroughly with the soil. Water was mixed with it for reaction to occur and then a

sufficient timc was allowed to complete hydration. Afterwards, the sample was

subjected to permeability test. Permeability of sandy soils was determined by

performing falling head permeability tests on the respective samples, while for clay soil

consolidation tests were performed.

Falling head penneability test was performed using a 62.5mm dia and 100.Omm

high cylindrical sample enclosed in a perplex permeameter. On the other hand,

consolidation test on lime treated clay was performed on 62.5 mm dia and 25.4 mm

thick cylindrical sample. In the research scheme, limc content was varied up to 5% and

the rcaction timc was varied up to 14 days, i.e., aftcr mixing a particular soil with a,dcfinite percent of lime and sufficient watcr, the mixture was allowed to complete

hydration at room temperature for 4, 5, 8 and 14 days before testing.

Test results show that regarding to permeability, cohesive soil was more

sensitive than cohcsion-Iess soils. Permeability incrcased in case of fine-grained soils

(i.c., both the finc sand and clay) with the increase of limc content, but it decreased for

relatively coarse-grained soil. Void ratio of lime treated soil was influenced by the

addition of lime. For soils with having substantial amount of fines (say, a fine sand and

the clay), it was observed that void ratio increased, while for the sand having less fines

exhibited a decrease in void ratio with lime content. The permeability characteristic

also changed accordingly. Aging had no affect on the permcability and void ratio of

untreated soils, but after a certain period of time, the lime treated sand exhibited more-

or- less stablc penneability characteristics during a span of about 30 hrs.

iv

CONTENTSAcknowledgementAbstractContentList of figure'sList of TableNotations

CHAPTER ONE

Introduction

iiiivv

viiX

XI

1.11.2

GeneralObjective of the study

I4

CHAPTER TWO

Literature Review

GeneralMechanism of lime stabilizationFactor affecting lime stabilization

2.12.22.3

2.3.12.3.22.3.32.3.42.3.5

SoilLimeWaterCompaction conditionAge effect on lime stabilized soil

568

816212125

2.4 Effect of lime treatment on the physical andengineering properties of soil

25

2.4.12.4.22.4.32.4.5

Atterberg limitSpecific GravityPermeabilityCompressibility

26282931

CHAPTER THREE

Laboratory Investigation

3.13.23.3

GeneralTest proggrammeMaterial used

3.3.1 Soi~~

v

32323636

3.4

3.5

3.3.2 Lime3.3.3 Water

State variables

Preparation of the lime-treated soil specimen

3740

40

41

CHAPTER FOUR

Results and Discussions

4.14.2

GeneralTest results and discussions 44

44CHAPTER FIVE

Conclusions and Recommendations for the future Research

5.15.25.3

GeneralConclusionsRecommendations for future studyReferencesAppendix

VI

5858606165

List of figures

Figure no Description PageFig. 2.1 Coefficient of permeability for sodium illite after Olsen (1961). 10Fig. 2.2 Ratio of the measured flow rate to that by the Kozeny-Carman 10

equation for several clays after Olsen (1961)

Fig. 2.3 Plot ofk against permeability function after Das (1983). IIFig. 2.4 Influence of degree of saturation on permeability of Madison sand 12

after Mitchell, Hooper and Campanella (1965)

Fig. 2.5 Influence of degree of saturation on permeability of compacted 13silty clay after Mitchell, Hooper and Campanella (1965)

Fig. 2.6 Dependence of permeability on the structure of silty clay after 14Mitchell, Hooper and Campanella (1965).

Fig. 2.7 Lime stabilization ranges of grain distribution after Kezdi (1979) 17Fig. 2.8 Effect of compactive effort on compaction of natural soil after 22

Singh and Punmia (1990)

Fig. 2.9 Variation of unconfined compressive strength with compaction 24delay time after Sastry et.al. (1987)

Fig. 2.10 Alteration of Atterberg limit by adding lime after Brandl (1981) 26

Specific Gravity vs. lime content curve (after Brandl. H. 1981)

Fig.2.11 Effect of lime content on Atterberg limit of a silty clay soil reported 27from Ahmed (1984)

Fig. 2.12 Influence of lime content on the linear shrinkage of clay after Bell 28(1988)

Fig. 2.13 Variation of Specific Gravity with lime content after Brandl, (1981) 29

Fig. 2.14 Alteration of Permeability coefficients by adding lime after Brandl 30(1981)

Fig. 2.15 Alteration of optimum water content at proctor density by adding 31lime after Brandl (1981)

VII

Fig. 3.1 Map of Bangladesh showing study locations 34

Fig. 3.2 Flow chart's of the experimental work 35

Fig. 3.3 Grain size distribution of untreated soils. 38

Fig. 304 Specific gravity of soils at different lime content 39

Fig.4.la Relationships of void ratios between two observations under 50otherwise similar test conditions (soil-I)

Fig.4.lb Relationships of void ratios between two observations under 50otherwise similar test conditions (soil-2)

Fig. 4.2 Relationships between permeability and lime content for soil-3 51

Fig. 4.3 Relationships between permeability and vertical load for soil-3 51

Fig.404a Relationships between void ratio and lime content for soil-I 52

Fig.404b Relationships between void ratio and lime content for soil-2 52

Fig.4.5a Relationships between permeability and lime content for soil-I 53

Fig.4.5b Relationships between permeability and lime content for soil-2 53

Fig.4.6a Relationships between void ratio and reaction time for soil-I 54

Fig.4.6b Relationships between permeability and reaction time for soil-I 54

Fig.4.7a Relationships between void ratio and reaction time for soil-2 55

Fig.4.7b Relationships between permeability and reaction time for soil-2 55

Fig.4.8a Long term permeability after different reaction time for soil-I 56

Fig.4.8b Long term permeability after different reaction time for soil-2 56

Fig.4.9b Relationships between void ratio or f(e) and permeability of soil-I 57

Fig.4.9b Relationships between void ratio or fee) and permeability of soil-2 57

Fig. Ao4.la Dial reading vs. time curve for soi-3 (0% lime; 6.25 -50.0 kPa) 66

Fig. Ao4.lb Dial reading vs. time curve for soi-3 (0% lime; 100.0 -800.0 kPa) 67

Fig. Ao4.2a Dial reading vs. time curve for soi-3 (I % lime; 6.25 kPa-50.0 kPa) 68

Fig. Ao4.2b Dial reading vs. time curve for soi-3 (I % lime; 100.0 -800.0 kPa) 69

viii

Fig. AA.3a Dial reading vs. time curve for soi-3 (3% lime; 6.25 kPa-50.0 kPa) 70Fig. AA.3b Dial reading vs. time curve for soi-3 (3% lime; 100.0 -800.0 kPa) 71Fig. AAAa Dial reading vs. time curve for soi-3 (5% lime; 6.25 kPa-50.0 kPa) 72, Fig. AAAb Dial reading vs. time curve for soi-3 (5% lime; 100.0 -800.0 kPa) 73Fig. AA.5 Void ratio vs. Log pressure curve for soi-3 74

ix

List of Tables

Table Nos. Description Page

No.Table 2.1 Typical value of coefficient ofpenneability. 16Table 2.2 Usual content of hydrated lime in different soil after Naasra, 16

(1987).

Table 2.3 Usual content of hydrated lime in different soil after Ingless and 17Metcalf (1972).

Table 2.4 Properties of lime after Naasra, (1986) 20Table 2.5 Requirement that must be meet by limestone's on natural calcium 20

carbonates in order to provide stabilizing lime by Ingless and

Metcalf (1972).

Table 2.6 Properties of the theoretically pure lime after Ghos (1987) 21Table 3.1 Detail of laboratory test performed on the three types of soils. 33Table 3.2 Physical properties of the soil used for lime treatment. 37Table 3.3 Constituent of lime from chemical analysis after Mollah, (1997) 37Table 4.1 Some test results from soil I and 2 (Sandy soils) 48Table 4.2 Some test results from soil-3

49

x

Notation

k = Coefficient of permeability.

n Porosity

S Specific surface area of the soil solids.

S, Surface area per unit volume.

11 = Viscosity

C, = Shape factor

c, = Compression index

cy = Co-efficient of consolidation

ay Co-efficient of compressibility

e Void ratio

D Effective dia. of the particle.

a, Specific gravity of the soil solid.

Yw = Unit weight of water

V = Volume of soil mass.

W, = Dry weight of soil grain.

Cu Uniformity coefficient of soil.

C, = Coefficient of concavity of soil.

Yd = Dry density of soil

Wp Plastic limit

WL Liquid limit

MIT= Massachusetts Institute of Technology

ASTM = American Society of Testing Materials

AASHTO = American Association of State High ways and

Transportation Officials.

XI

CHAPTER ONE

Introduction

1.1 General

The soil improvement technique, stabilization, is applied when there is a

particular and obvious deficiency in the potential a material property. The usual

deficiencies are associated with strength and stiffness, excessive sensitivity to change

in moisture content, high permeability, poor workability, tendency to erode, etc. By

stabilization or treatment of soil, one or morc of such deficiencies are improved up to

the desired level by altering the associated properties. In the past, soil stabilization with

lime was used in the field of highway, railroads and airport construction to improve rail

beds and bearing layers. Meanwhile this method is employed also to the construction

of embankments, soil exchange in sliding slopes, the backfill of bridge abutments and

retaining walls, soil improvement under foundation slabs and for lime piles (for

foundation, excavation pits and slope stabilization.)

A lot of works on cement and lime stabilization were reported in literature, such

as for general behavior of lime-treated soils (Brandl, 1981), for construction of roads

(Ingles and Metcalf, 1972; Naasra, 1986; Haunsmann, 1990), for agricultural road

network (Kezdi, 1979; Ahmed, 1984; Rajbonshi, 1997), for sub. base and base

construction of roads on non-plastic alluvial soils of flood plains (Bangladesh

Transport Survey, 1974), etc. In these works, the major engineering benefits are

expected to increase strength, stiffness, durability and volumetric stability.

At present Bangladesh is moving forward with large development projects

including construction of high rise buildings, bridges, oil storage tank, harbor and port

structures, pond constructions, haor and beel development structures such as fish-pass,

regulator, etc. Slope and settlement failures arc not unusual in Bangladesh. So, during

this stage of infrastructure development in Bangladesh, a detailed knowledge and

sound understanding of flow rate of water through soil and its effects on the

deformation behavior of soil are of utmost importance.

Bangladesh is a land of rivers and canals. Its ground formation mainly consists of

alluvial deposits. There are many large natural depressions known as beel, haor, baor

and many natural or man-made ponds. The hydraulic properties of naturally deposited

soils in many areas do not fulfil the requirement of construction especially related to

aquaculture. Due to lower water tablc in dry seasons, water nows from storage

reservoir, ponds, cte. through the soil by percolation or seepage. This problem is severe

in case of projects constructed on sandy and silty types of soils. Improvement of

strength and other properties of the soil by the addition of lime as admixture is simply

referred to as lime stabilization. Soil improvement in some locality is, therefore,

essential particularly for water retention purpose (especially, in Tangail, Manikgong,

Thakurgaon, Serajgong, Rangpur, Dinajpur, Cox's Bazar area). Nowaday, different

mechanical, chemical or electrical stabilization technique of soil has been developed.

Depending upon the availability of equipment and technology, generally mechanical

technique (compaction) is used to reduce the permeability. However, this procedure is

limited to clay and silty soils. On the other hand, cement, lime, cow-dung, bitumen, ny

ash, etc. can be used as stabilizing material for sandy soil. Of them, cow-dung, nyash,

rice-husks, lime, etc are used for solving the water retention problem at locations

where sandy soils dominate the permeability characteristics. Besides, cow-dung and

lime serve special purposes in aquaculture, such as the better growth of phytoplankton

and zooplankton, reducing pH and turbidity etc. Lime facilitates sunlight so as to

promote photosynthesis and thereby increases dissolved oxygen in water. Lime also

provides a thin layer and thus separates water from coming in contact with permeable

layer, and subsequently changes permeability of base soil.

Although a number of researches were carried out to investigate the strength and

deformation characteristics of stabilized soils, little attempt has been made to assess the

hydraulic characteristics of such treated soils in Bangladesh. The characterization of

hydraulic properties of such soil is important for permeability and seepage analysis of

highways, barrage, dyke, foundation, ponds, etc. if the underlying or the protecting soil

is stabilized with a method mentioned earlier. This has special importance in fishery

sector, where the ponds or dykes for aquaculture consist of sandy or silty soil (e.g. the

northern part of Bangladesh). In such places, water retention is ensured usually by

providing clay lining on the high permeable deep-seated soil-mass. On the other hand,

lime is periodically added to pond water for better production of fish as stated above.

Therefore, lime is always mixing up with soil, which after some time may behave justlike lime treated soil.

2

In Pisci-culturc, lime is frequcntly uscd in watcr for various purposes (not rclated

to pcrmeability characteristics). Liming may best be viewcd as a remedial procedure

nccessary in acidic ponds to accomplish one or more of the following tasks:

a) To improve or permit survival of aquaculture species,

b) To permit normal rcproduction and growth, and

c) To insure response of fish population to fertilization and other managementprocedure.

Thc most spectacular benefits of liming result when lime applications permit

fishes to survive, reproduce and grow in bodies of water, which were previously too

acidic for fish (Boyed, 1990). I-licking (1962) stated that liming is a technique for

increasing the response to fertilization; it is not a substitute for fertilization. Liming

increases p" of water and improves survival, reproduction, and growth of aquatic life.

Liming increases the p" of bottom mud and thereby increases the availability of

phosphorus addcd in fcrtilizer (Boycd and Scarsbrook. 1974). Bowling (1962)

dcmonstrated that liming increased benthic production in fertilized ponds apparently

through increased nutrient availability rather than increased pH. Pamatmat (1960)

suggested that liming increased microbial activities and diminishes the accumulations

of organic matter in pond bottoms and fibrous recycling of nutrients. Liming increases

the alkalinity of water, thereby increasing the availability of carbon dioxide for

photosynthesis (Arce and Boyed, 1975). Greater alkalinity after liming also buffers

watcr against drastic daily changcs in p" common in eutropic ponds with soft water.

The net effect of changes in water quality following liming is to increase

phytoplankton productivity, which in turn, leads to increased fish production.

To support the proposition, Brandl (1981) showed that the permeability of lime

treated soil may be changed over one or two decimal exponent. Therefore, a possibility

exists that lime treated sand and silt can be used as a lining instead of clay lining in the

aquaculture projects facing water retcntion problem.

In carly day, ponds/water reservoir is gcnerally constructed in a region, where the

water retention capacity is more and other hydraulic properties are favorable to the

aquaculture. There was an ample opportunityJor the engineers to avoid unsuitable site

or unsuitable construction material source whenever the required condition did not

3

fulfilled. But nowaday, this scope has been limited. In the developing countries,

considering the conventional construction materials that are being adopted today, there

appears to be an ample scope for exercising further economy by the way of

incorporating locally available materials and adopting the soil stabilization technique to

the maximum extent possible (Khan, 1989).

1.2 Objective with specific aims and possible outcome

The study is aimed at determining the permeability characteristics of lime treatedsoils. The objectives of the study arc:

i) To characterize the alteration in permeability nature of soils after being treated

with lime.

ii) To evaluate, for a given soil, the effects of lime content on the permeability

characteristics.

iii) To investigate, the long-term (i.e. time effects) permeability characteristics oflime treated soils.

iv) To evaluate the effect of curing age (reaction time) of lime during mixing on

permeability.

4

CHAPTER TWO

Literature Review

2.1 General

Considering the existing atmospheric condition and economy, lime stabilization

is performed to increase strength, to improve permeability and erodibility of the side

slope of embankment, to increase overall durability of the pond and earthen dyke so

that the over all aquatic production would be increased. It has been proved that the use

of lime is favorable for fish production. The aqua scientists use it extensively to

improve the water quality. Liming increases the pH of bottom mud and thereby

Increases the availability of phosphorus added in fertilizer (Boyd and Scarsbrook,1974).

In Civil Engineering purposes, field as well as laboratory experiments were

started by the Texas Highway Dept. in 1948. Development of theory, for the

mechanism of lime stabilization was started from 1950 and the extensive study on

mechanism of lime stabilization was done from 1960. In this regard, Eades and Grimes

(1960), Kezdi (1979), Broms (1984) did the major work.

Lime stabilized soil are used to improve the engineering properties of soil in the

field of high way, railroad, airport construction. Brandl (1981) showed that lime could

also be used for the construction of embankment slopes, in the back fill of bridge

abutments and retaining wall. He also showed that specific gravity of lime treated soil

takes longer duration to get stabilized thus indicating long-term transformations of the

chemical bound water and the gel. By adding lime, permeability of treated soil can bechanged one or two decimal exponents.

Kezdi (1979) pointed out that lime stabilization is the addition of calcium in the

form of CaO or Ca(OHh which will reduce soil plasticity, increases strength and

durability, decreases water absorption and swelling.

2.2 Mechanism of lime stabilization

Many researchers, even nowaday is working with the theory of lime

stabilization. Indian Road congress (lRC, 1973b) and Haunsmann (1990) have

described the basic mechanism of soil-lime interactions. The basic mechanism of lime

stabilization can be classified as follows.

a. Cat-ion exchange

b. Flocculation /Agglomeration

c. Carbonation

d. Pozzolanic reaction

a. Cat ion Exchange

Cat-ion exchange capacity of soil depends upon the pll value of the soil. Clay

soils composed of different mineral and have different cation. Replace-ability of cation

primarily depends on diffused double layers. The general order of replace-ability of

common cat-ion is Na+<K+<Ma++<Ca++. Mono-valent cations are usually replaced by

divalent or multivalent cations.

The reaction of lime with three layers material, which are montmorllinite,

Kaolinite and illite, begin by the replacement of existing cat-ions between the silicate

sheets with Ca++. Following the saturation of inter layer positions with Ca++, the whole

clay minerals deteriorate without the formation of substantial new crystalline phases.

Eades and Grimes (1960) indicated to the formation of new crystalline phases in the

soil lime electrolyte system due to the addition of lime to the soil in presence of water,

which are tentatively identified as calcium silicate hydrate. Cat-ion exchange capacity

increases as the pHof the soil increases.

b. Flocculation/Agglomeration

Flocculation of the soil particle occurs due to the mixing of soil with lime in

presence of water. After cation exchange of soils and lime take place, agglomeration of

the flocculated particle occurs. Kezdi (1979) pointed out that immediately after mixing,

6

the soil structure starts to undergo a transformation. Flocculation and coagulation

begin, and then the clay particles form much larger grains in the silt fraction. This, in

turn, will modify the Atterberg limits and the compaetion properties and so in practice

the soil becomes much easier to handle in the eourse of earthwork. Diamond and Kinter

(1965) suggested that the rapid formation of hydrated calcium aluminate (which is a

cementing material) is responsible in the devclopment of flocculation/agglomeration

tendencies in the soil lime mixture.

c. Carbonation

When soil lime mixture is exposed to air, lime react with atmospheric carbon

dioxide to form relatively weak cementing agents such as calcium carbonate or

magnesium carbonate (Haunsmann, 1990). This reaction is the slowest of all the

reactions involved in a soil-lime system and as in pozzolanic reaction, requires that the

mixture must be thoroughly compacted. Eades et al. (1962) demonstrated that although

carbonation takes place, the strength gain by virtue of cementation of soil grains with

calcium carbonate is negligible.

d. Pozzolanic reaction

Long-term chemical reaction of lime with certain clay minerals (silicate and

aluminates) of soil, in presence of water is referred to pozzolanic reaction. The minerals

that react with lime to produce a cementing material are known as pozzolans. Possible

source of silica and alumina in a typical soil include clay minerals are quartz, feldspars,

mica and similar silicate or alumino-silicate minerals either in crystalline or amphorous

in nature. When lime is added to the soil in presence of water causes an instantaneous

rise in pH of the molding water due to the dissociation of the Ca(OHh in water.

Eades and Grims (1960) observed that high pH causes silica and alumina to be

dissolved out of the structure of the clay minerals and it combines with the calcium to

form calcium silicate and calcium aluminates. The calcium ions combine with reactive

hydrous silica and alumina and form gradually hardening cementetious material. This

reaction will continue as long as Ca (OH) 2 exists in the soil and there is available silica.

This mechanism may be referred as "Through Solution". Soil lime pozzolanic reaction

7

usually does not appear until after long curing period and then only in cases where a

high percentage of lime was added. Pozzolans posses little or no cementitious value in

finely divided form, but in the presence of moisture, it chemically reacts with calcium

hydroxide at ordinary temperature to form components possessing cementitiousproperties.

2.3 Factor affecting permeability of lime stabilized Soils

Permeability of lime-stabilized soil depends upon various factors. In thefollowing section some of the factors are discussed.

2.3.1 Soil

a. Soil types i.e. shape and size of the soil particle

Permeability varies approximately as the square of the grain size since soils

consists of many different sized grains. Based on the experimental report on sand filter,

(0.1 mm and O.3mm) Hazen (1892) suggested the following formula for permeabilitydetermination.

Permeability, k=CD2'0 ..............•.... (2. I)

Where C is constant approximately equal to 100 when effective diameter 0'0 is

in cm. and the formula is also useful for permeability determination of clean sand andGravel.

Cassagrande (1937) stated the empirical relation for permeability determinationof fine or clean sand with bulky grains as

k= lAO k 085 e2 ..•...•.........•... (2.2)

where, k085 is the permeability at void ratio = 0.85

Different attempt has been taken to correlate permeability with the specificsurface area of the particle. Kozeny (1907) gives one such relationship

I nJ

k= , x --, (2.3)K,'l S, I-n

where, k= Coefficient of permeability in cm/sec per unit hydraulic gradient.

8

n= Porosity,

S,= Specific surface of particle (cm2/cm\

TJ=Viscosity (y-sec/cm2),

Kk= Constant, equal to 5 for spherical particle.

On the basis of experiment, Loudon (1952-53) developed an empirical formula

LoglO(kS/)= a + bn .......................... (2.4)

Where a and b are constant and equal to 1.365 and 5.15 at 10°C. Loudon demonstrated

that the permeability of course grained soils inversely proportional to the specific

surface, at a given porosity.

Kozeney-Carman (Kozeney, 1927; Carman, 1956) developed the formula as

e'k=--_x--C,T' S~ I-e

..................... (2.5)

Where, k= Absolute permeability

T= Tortuosity

S, = Surface area per unit volume of soil solid's.

C, = Shape factor.

This formula is worked well for coarse-grained soils such as some sand and silts and

has serious discrepancies for clay soil. The discrepancies between the theoretical and

experimental value are shown in Fig. 2.1 and Fig 2.2 based on consolidation-permeability tests.

9

10.'

0.6

////

0.60.'

,/

/ElIPft~"111 //

///

• /"''-Eq.t2 ..,////////,

I

_ __ $cod;•••"", ill;~

--- 10.' N-N.cl

0.2

10~

Por~irv n

Fig. 2.1 Coefficient of permeability for sodium illite after Olsen (1961).

100

~,g~ 10u'Q~0.

E~iI••E 1.0'0.!1:;ex;

0.10.2 0.4 0.6

Porosiry n0.8

Fig. 2.2 Ratio of the measured flow rate to that predicted by the Kozeny-Carman equation forseveral clays. Curve I: Sodium illite, IO"JN NaCI. Curve 2: Sodium illite, 1O"4N Nae!. Curve3: Natural Kaolinite, Distilled water fhO Curve 4: Sodium Boston blue clay, IO-'N NaCI.Curve 5: Sodium Kaolinite, 1% (by Wt.) sodium tetraphospate. Curve 6: Calcium Bostonblue clay, IO"N Nael, after Olsen (1961).

10

b. Void ratio of the soil

Permeability increases with increases of void ratio. For coarse grained soil

For coarse-grained soil C changes a little and can bc writc

3k, e, 1+ e,-=--x--k, 1+ e, e,'where, kJ and k, are the coefficient of permeability of a given soil at void ratio e) and

e2 respectively. Based on the mean hydraulic radius concept for the soil, the following

relationship is obtained,

.:L,e2

It has been found that a semi-logarithmic plot of void ratio versus permeability

is approximately straight line for finc grained as well as coarsc-grained soil. A typical

plot workcd on uniform Madison sand is presentcd in Fig. 2.3 based on constant head

tcst.

0.7

0.6

+:::". 0.5

+

.'1 ••.'1 +.

--- '.'

0.6

.••.,-,"'0 Q

o

• •

0.5003 0.4k. mm/.

0.20.1

,,;::o.~ /'..; .:..20.3 /-. -c: "0,,, '" 0

~ -E / 0<>':0 0.2 ~,. .'~ -",---/---;,:'.-l. .,/. ~

0.1 /", :,- ,, .,:,... I, ,

Fig. 2.3 Plot ofk against permeability function after Das (1983).

11

c. Degree of saturation

When air is entrapped In the voids, it reduces the degree of saturation and

permeability decreases. Water contains dissolved air and it may get liberated while

changing the permeability. So, permeability increases with the increases of degree of

saturation. The variation of the value of permeability (k) with degree of saturation for

Madison sand as shown in Fig. 2.4 and Fig. 2.5

0.8

1009580 85 90Oegree: 01 'Dturetion, %

Madison sand• = 0.797

/./;'"

~

-0.3

0.275

0.7.::EE.0.8~ig 0.5IIaj 0.4

~

Fig. 2.4 Influence of degree of saturation on permeability of Madison sands after Mitchell

ct .1. ( 1965).

12

100

80

~60EE

a80

Kneading <:omjlaction drYunil ••••ight ~ 108 Ib/h3116.98 kN/m3)Void IlItio ~ 0.57

w~ 11.8%

84 88 92 960•••,..,.of "lu'alion, %

100

•

Fig. 2.5 Influence of degree of saturation on permeability of compacted silty clay. (Note:

Samples aged 2 J days at constant water content and unit weight after compaction

prior to test) Redrawn after Mitchell ct:ll. (1965).

d. Compaction of soil particles

For sands and silts this is not important; however for soils with clay minerals,

this is one of the most important factors. Permeability in this case depends on the

thickness of water hcld to thc soil particles, which is a function of cation exchange

capacity, valence of the cations, etc. Other factors remaining the same, the coefficient

of permeability decreases with increasing thickness of the diffuse double layer.

e. Soil structure

Fine-grained soils with a nocculated structure have a higher permeability then

those with a dispersed structure. This fact is demonstrated in Fig. 2.6 for the case of

silty clay. The test specimen was prepared to constant dry unit weight by kneading

13

compaction. When Moisture content increases the soil becomes more dispersed. With

increasing degree of dispersion, the permeability decreases .

•Sltu,.tion 95%

SaturatK>n 90%

10.6

.=:EE~

10.'

10-'

13 15 17 19Molding water content. %

21

Fig. 2.6 Dependence of permeability on the structure of silty clay. Redrawn after Mitchell et al.(1965).

f. Property of the Permeant

Permeability is directly proportional to the unit weight of water and inversely

proportional to its viscosity. Through the unit weight of water does not change much

with the change in temperature there is a great variation in viscosity with temperature.

When other factor remaining same, permeability at a given temperature (kT) is given by

................... (2.6)

where, Tl is the viscosity of water.

14

Muskat (1937) pointed out that a more general co-efficient of permeability

called the physical permeability Kp is related to the Darcys co-efficient of permeabilityK as follows:

K = K -'1..-P A

"..................... (2. 7)

In any soil, Kp has the same value at temperatures as long as the void ratio and the

structure of the soil skeleton are not changed for all fluids.

g. Organic matters present in the soil

Presence of organic matter influences the permeability. Organic matter has the

tendency to move towards critical flow channels and choke them up and thus

decreasing the permeability. Rodriguez et al. (1988) noted that lime has little effect on

highly organic soil or soils without clays.

h. Adsorbed water with soil particle

Adsorbed water surrounding the fine soil particles are not free to move thus

reduces the effective pore space available for the passage of water. Casagrande's crude

approximation is to take O. I as the void ratio occupied by the adsorbed water hence it is

the square of the net void ratio (i.e., void ratio= e _O. I).

i. Effect of stratified soil layer

In general,' natural soil layer is stratified. Their bedding planes may be

horizontal inclined or vertical. Assuming each layer homogeneous and isotropic, it has

own value of co-efficient of permeability. The average permeability to the whole

deposit will depends upon the direction of flow with relation to the direction of the

bedding planes. Typical values of coefficient of permeability for various soils are givenin Table 2.1

15

Table 2.1 Typical value of coefficient of Jlermeability

Materials Coefficient of permeability(mm/sec)

Coarse IOta 10'Fine Gravel. Coarse and medium sand 10.2 to 10Fine sand, Loose silt 10.4 to 10.2

Dense silt, Clay silt 10.5 to 10.4

Silty Clay, Clay ID.' to 10.5

2.3.2 Lime

a. Lime Content

Since lime reacts with soil to form some new compounds, which improve the

engineering properties of soil, lime content is an important factor. The usual content of

hydrated lime for different types of soil are given in Table 2.2 and 2.3.

Table 2.2 Usual content of hydrated lime in different soil (% by weight ofdry soil to lime) after Naasra (1987).

Soil Type Stabilization (lime %)Crushed rock not recommended

Well-graded clayey gravel's 2Pure sand not recommendedSilty sand not recommended

Clayey sand 2-4

Clayey silt 2-4

Silty Clay 2-6Plastic clay 3-9Highly plastic day 3-9

Organic soil not recommended

16

Table 2.3 Usual content of hydrated lime in different soil (% by weight of dry soil)Ingless and Metcalf (1972).

Soil Type Stabilization(Lime %)

Crushed rock not recommended

Well-graded clayey gravel's 3

Sands not recommended

Sandy clay 5

Silty clay 2-4

Plastic clay 3-8

Highly plastic day 3-8

Organ ic soi I not recommended

From the above table, it can be seen that the usual content for lime for silty sand

is 2-4% and for sandy clay it is 5%. It can be also observed that lime percent increases

as the soil become coarser to fine grained from stabilization viewpoint. Brandl (1981)

pointed out that the more cohesive and more reactive the untreated soil is, the more

increases the permeability of the mixture according to the immediate flocculation. The

maxima are gained at lime amounts between I% for inactive silt to 10% for active

clays. Kezdi (1979) classiry the soil from lime stabilization viewpoint into three

categories that is represented in figure 2.7. From the figure, it is observes that in range-

A, no stabilization is possible since the available equipment simply cannot work these

17

Fig2.7 Lime stabilization ranges of grain distribution after Kezdi (1979)

. 0001aOI0.110100

Grovtl Sand .1140 Sil Cloy'M..I',

'\ I I 01\ ., \ .-e Limo\ " \ . ldiflicull Ia admixl -\. T C6 '\ CNiclc ~m.""""",-\I B I, \ and Iimt t,o-al. ...••.•....

I\.. MKhonicol ord -'LO Ctmtnl slobilizolion 1\A ,

Unsuiloblt I "20I -'\ --H. "0 I

-

course materials. In range n, thc soil behavior is governed mainly by the grain

distribution itself. In rangc C, mechanical stabilization is not fruitful by hydraulic

binders, cement, etc. It would only be economical in the case of clay soil.

Optimum lime content: May be defined as the lime content at which thepercentage of such additional lime increment will not produce appreciable increase in

the plastic limit. According to Diamond and Kinter (1965), lime content above the lime

fixation point for a soil will generally contribute to the improvement of soil

workability, but may not result in sufficient increases of strength.

From the literature review, it can be concluded that lime percent varies from soil

to soil. To achieve the minimum and the maximum permeability, strength and specific

gravity (i.e., overall durability of the structure) optimum lime contents is the lime

content by which the maximum strength and the maximum or the minimumpermeability of soil can be achieved.

b. Lime types

Lime may be divided into three categories as follows:

i. Fat Lime: This lime known as fat lime because it increases 2 to 2.5 times in volume,

when slacked. It contains about 95% calcium oxide and about 5% other materials

inform of impurities. This lime is also sometime known as pure lime, rich lime, white

lime or high calcium lime. It is obtained by burning lime stone which containing mostly

calcium carbonate in atmosphere, carbon dioxide is driven out, leaving back calcium

oxide (CaO), known as quick lime. Fat lime is obtained by slacking quick lime. Setting

of this lime is entirely dependent upon the atmospheric oxygen. For setting, this lime

absorbs carbon dioxide (CO,) from atmosphere and after chemical reaction gets

converted into calcium carbonate (CaCo,), which is quite hard substance, insoluble inwater. Sctting and hardening actions of this lime arc vcry slow.

ii. Hydraulic lime: This lime has the property of setting under water. It is obtained by

burning limestone, containing lot of clay and other substances that develop

hydraulicity. Hydraulicity of this lime depends upon the amount of clay and type of

clay present in it. Silica, alumina and or iron oxide are present in chemical combination

18

with calcium oxide. Depending upon the amount of clay (silica and alumina) present,

hydraulic limcs may bc further divided into following three categories.

Feebly hydraulic lime: It contains clay (silica, alumina or iron oxide) less than 15%.

The usual percentage of these constituents varies between 5% to 10%. On slacking, it

increases in volume by very small amount. It slacks slowly.

Moderately hydraulic lime: This Iimc contains 15 to 25% silica and alumina. On

slacking, it increases in volume by very small amount. It slacks very slowly.

Eminently hydraulic lime: This lime contains 25 to 30% silica and alumina. It

resembles very much to Portland cement in chemical composition. Slacking of this lime

is hardly noticeable. Its initial setting starts after two hours and the final setting within48 hours.

c. Poor limc: This lime contains more than 30% of clay. It slacks very slowly. It does

not dissolve in water. It forms a thin plastic paste with water. This lime is also known

as lean lime or impure lime and hardens and sets very week slowly.

Boyed (1990) pointed out that liming material most frequently used is

agricultural limestone, which is prepared by finely crushing limestone. Agricultural

lime (Calcium carbonate) is not suitable for stabilization. Dolomitic lime is usually not

as effective as calcium lime. In order to give a common quantitative base, lime content

is expressed as equivalent 100% pure hydrated lime. On a mass basis pure quick lime is

equivalent to 1.32 unit of hydrated lime. Limestone is calcite (CaCO)), dolomite

[CaMg(CO)hJ or some blend of these two substances. There is some confusion to the

actual composition of locally available liming material. Basic slag, a by-product of steel

making, contains calcium carbonate and phosphorous, so it is both a liming material

and fertilizer. Blast furnace slag, also a by-product of steel making, is comprised

largely of calcium silicate, but these calcium silicate slags are not suitable for fishculture in pond.

Lime rapidly reacts with any available water producing hydrated lime, releasing

considerable amount of heat. The water content of common slurry lime can range from

80-200%. Table 2.4 presents the property of hydrated, quick and slurry lime.

19

Table 2.4 Properties of lime after Naasra (1986)

Parameters Hydrated lime Quick Lime Slurry Lime

Composition Ca(OH)2 CaO Ca(OH)2

Form Fine Powder Granular Slurry

Equivalent Ca(OH), / Unit 1.00 1.32 0.56 to 0.33Mass

Bulk Density (Kg/m3) 450 to 560 1050 1250

According to Mateos (1964), lime can be divided chemically into two categories.

Hydrated lime: It is divided into three groups

Calcite [Ca(OHhl, commonly known as hydrated lime, slaked lime or builder's lime.

Dolometic monohydrate, Ca(OHh+MgO and Dolomitic dehydrate Ca(OHh+Mg(OHh

Quick lime: It is divided into two groups

Calcitic (CaO) and Dolomitic [CuO+MgO]

On chemical analysis of calcitic hydrated lime has found 75.677% quick lime

and 24.33% water. Dolomitic monohydrate lime has 15.79% water and 84.21 %

dolomitic quicklime. Dolomitic hydrated lime has 27.27% water and 72.73% dolomitic

quicklime. Table 2.5 shows the different constituents of quicklime and hydrated lime

after Ingles and Metcalf (1972) and Table 2.6 shows different properties for soil

stabilization after Ghos R. M (1987).

Table 2.5 Requirements that must be meet by limestone's on natural calcium

carbonates in order to provide stabilizing lime after Ingless and Metcalf

(1972)

Property Quicklime (CaO) Hydrated lime Ca(OHhCalcium not less than 92% Not less than 95%magnesium oxides

Carbon dioxide

In the oven not more than 3% Not more than 5%Out of the oven not more than 5% Not more than 7%Fineness Not more than 12% retained on No.

180 sieve.

20

Table 2.6 Properties of the Theoretically Pure Lime after Ghos R. M (1987)

Chemical name Quicklime Hydrated Lime

Calcium or magnesia or Calcium MagnesiumCalcium magnesium hydroxide hydroxideoxide oxide

Chemical formula CaO MgO Ca(OHh Mg(OHhCrystalline cubic cubic Hexagonal Hexagonalformula

Melting point 2570vc 2800vc - -Decomposition - - 580"c 745vcpoint

Boiling point 2850vc 3600vc - -Molecular weight 36.09 40.32 74.1 58.34Specific gravity 3.40 3.65 2.34 2.40

It shows from the above discussion that for soil stabilisation Hydraulic or Poor

lime will be best variety to work. If they are used in the hydrated form, duration of

effective curing time will be small.

2.3.3 Water

Distilled water is preferred for any research work. When requirement of the

water is high, potable water is used for lime stabilization. Water containing organic

matter should be avoided. Seawater may be used, where bituminous seal do not exist.

2.3.4 Compaction condition

Compaction is the process by which soil particles are re-arrange and packed

together in a close state of contact by mechanical or any other means in order to

decreases porosity of the soil and then increases the dry density, which reduce the

pcrmeability. Compendium (1987) pointed out that the maximum dry density normally

continues to decrease as thc lime content increases. Further more the optimum moisture

content increases with the increase of lime content. Haunsmann (1990) stated that the

21

flocculation and ccmentation will make the soil more dirticull to compact and thcmaximulll ury uCl1sily achieved with a parlicuiilr l:OlllPHclivc ctTort. is reduced.

2.3.4.1 Compactive efforl

Compaction on the lime-stabilized soil as well as untreated soil can be done by

differcnt methods in thc field and in the laboratory. Three recognized method ofcompaction is namely

a. Standard proctor test method

b. Modified Standard proctor test method

e. Harvard minialure compaction

Singh and Punmia (1965) p-?inted oul thaI. on illereasing compaction effort results in

an increase in maximum dry dcnsity and dccrease in optimum moislUre conlent (fig2.8).

10 11 12 13 1. 15 f8 17 f8 19

Water content, percent

,. !-Sltu lion Ino.:, ,," /"

~ V"'" \\

~I

/ I

2 '.-lit' \

~..l- I,/ \ ~

,, I, ,

.//' vr ,

.~ \ ,:-..I I

/ \

~\ 1\\ I

-

1/ ~ \ ,),.1. no of ptimun.s

-- j -a- JOblowl.I--e- l'bloWI--.A.- 20 bloW!

\..----'V -...- 2j: blow. -I

J I I

1.90

••••

'.lIS

I."

1.82

1.00

1.78

l.7e •

E~'"

•••

to

••••

. 1.De

Fig 2.8 Effect of cOll1pncHvc errort on cOIIII':lcfioll uf lI:ltllrnl soil after Sing aud PUlllllin

(1965).

22

2.3.4.2 Moisture content for Compaction

Moisture content plays an important role for soil compaction. Generally for soil

compaction, as the moisture content increasc, it increases soil strength up to the

optimum moisture content and then decreases. Optimum moisture content depends on

soil type and compactive effort. At different compactive efforts different optimum

moisture content of the soil can be obtained. For lime treatment, about 47% water is

required for hydration of lime. So the optimum moisture content of the lime stabilised

soil differs from the optimum moisture content of the untreated soil for the same

compactive effort. Serajuddin (1992) pointed out that at the equal level of compactive

effort, CBR value varies appreciably on the variation of the moisture content during

compaction. He also stated that optimum water content occur at 2% to 3% higher water

content than the optimum moisture content of the soil depending on the soil types.

2.3.4.3 Compaction delay time

Compaction delay time is the time interval between mixing of lime with soil

and compaction. As the reaction of lime with soils occurs slowly, it is not essential to

compacts the specimen immediately after mixing the soil with lime. Townsend and

Klyn (1970) observed that the compaction delay time of 24 hours can reduces the

strength of the specimen up to 30% as compared to the specimen prepared by

compacting immediately after mixing of lime. Sastry and Rao (1987) pointed out that

the delay of time for two hours between mixing and compaction; there is practically no

reduction in strength. But for further delay, the strength of soil-lime mixture continues

to fall (Fig. 2.9) Compendium (1987) pointcd out that granular soil lime mix should be

compacted as soon as possible and the delay time upto two days are not detrimental,

especially if the soil is not allowcd to dry out. Fine-grained lime treated soil can be

delayed upto four days after mixing.

23

3305% lime'

300

3% lime

270

240

2101 10

Com(J:tction delay time, fir (log scale)

100

Fig. 2.9 Variation of unconfined cOIIIIJl'essivc strength with compaction delay time anerSa,fry and Rao (1987)

Therefore, there are many controversial statements on the effect of strength due

to the compaction delay time. Among thcm, most of the authors stated that 24 hours has

no marked effect on the strength, On the other hand, some authors stated that

compaction delay time of 24 hours has marked effect on the strength of lime stabilized

soil. Fine-grained soil has less effect on the compaction delay time than those ofcoarse-grained soil do.

2,3.4.4 Mixing of lime with soil bcfol'c compaction

Mixing of lime with soil can be done in different ways. Compendium (1987)

pointed out that onc or two stage mixing, lime can be used for compaction. In two stage

mixing, half of the lime is mixed and the rest is added aller 18 hours. He observed that

24

due to two stages mixing unconfined compressive strength of the stabilized soil

increased. The reason for the improvement was due to the fact that on the first stage of

mixing the soil become more friable and as a result, soil becomes more effective inlime stabilization.

2.3.5 Age effect on lime stabilized soil

It has been stated earlier that effect on lime stabilized soil occur slowly. Lime

reacts with soil and the gain of strength is higher at initial stage of curing and the rate of

gain of strength reduces as the time goes on. Arman and Muhfakh (1972) stated that

lime has an initial reaction with soil taking placc during first 48-72 hours after mixing

and the secondary reaction starts aftcr that period and continues.

The rate of gain of strength is time dependent and depends on soil types. For

some types of soil, the rate of gain of strength with curing time is high but for others

the rate is slow: Brandl (1981) observed that the time dependent increase in shear

strength is approximately linear with the logarithm of time. From his study, it is seen

that the permeability decreases with curing time. With increasing curing time, the

mineral particles are cemented within the soil-lime-mixture; the fine skeleton is

embedded partly within a gelatinous intermediate mass, hardening products of the

binder grow into the voids of soil aggregate changing the void structure.

2.4 Effect of lime treatment on the physical and engineeringproperties of soil

Lime reacts with soil silica or alumina in the presence of water causing the

change of the physical properties of soil. The chemical-physical reactions in the soil are

rather complex and can be gencralized only in some cases. Some changes of the soil

parameters being interesting for practical application. Some of the important properties

of soil, which are changed due to the stabilization of soil with lime, are Atterberg limit,

permeability, strength, compressibility, stress strain character, volume change, shear

strength etc. In the following sections the various physical and engineering properties

of lime stabilized soils are reviewed.

25

2.4.1 Atterberg limit

Plasticity is the property of the soil, which allows to be defonned rapidly

without ruptures, without clastic rebound and without volume change. Due to the

addition of lime, structural transformation and flocculation begin immediately. This

causes a rapid change on the Atterberg limits. Brandl (1981) stated that higher the

amount of colloidal clay and the chemo-physical activity of the soil, the more likely is

the decrease of liquid limit (Figs. 2.1 a.a, b and c). Silts reaches in natural calcium show

an increase .The plasticity limit rises without exception, only with silts and sand reach

in calcium and dolomite tHe value in almost constant. Too much lime causes the

transgrcssion of the point of reversal (liquid limit, WL and plastic limit, wp). Generally

both liquid and plastic limits increase with time, because the attractive forces between

the soil particle increase and the absorbed water film is influenced. Thus the plasticity

of reactive soils is reduced considerably easing the workability on construction site.

Only inactive soil becomes even more plastic

[Symbol used were soil [, open circle (-0-) clay A-7-6 (sand 2[%, silt 54%, clay 25%);

soil II, solid circle (-.-) silt A4 (sand 15%, silt 73%, clay 12%); soil V, cross (-x-)

silt.sa. A-2-4 (A-4) (sand 59%, silt 36%, clay 5%]

26

Wp f%J Ip f%J0 SOIL I

Illil JOSOIL D•

• SOIL DIX SOIL Jl

20I_I

JO ---i8j~--,...• rn 10

20 rnr-1X-x--1.-'

1.0 2.5 5.0 7.5 1.02.5 5.0 7.5(b) (e)

Lime %1.02.5 5.0 7.5

(a)

Fig 2.10 Alteration of attcrberg limit by adding lime; Reaction time (curing age) in days as

parameter (drawn in rectangle): period from stabilization till test performance after Brandl(1981).

Generally soils with high clay contcnt or soils exhibiting a high initial plasticity

indcx require grcater quantity of lime for achicving thc non-plastic condition. If it can

bc achicvcd at all, the amount of rcductions in plasticity indcx varics with thc quantityand typcs of Iimc and also of soil (IRC, 1976)

Ahmcd (1984) pointcd out that plastic limit of a silty clay incrcascs with the

increase of limc content, while liquid limit and plasticity index dccreases with

incrcasing Iimc contcnt (Fig 2. I I and pig 2. I2). Shrinkage limit and linear shrinkage of

a clayey soil are also affected by addition of limc. Thc shrinkage limit increases while

lincar shrinkagc rcduccs as thc limc contcnt incrcascs (IRe. 1976). Iliit and Davidson

(1960), Pietsch and Davidson (1962) pointed out that thc plastic limit of soil gcnerally

increascs with thc addition of small amount of limc until certain critical lime content.

Callcd "lime fixation point". Rodrigucz ct aJ. (1988) stated that lime gencrally reduce

the plasticity indcx of high plastic soil but has little inllucnce on the plasticity index ofthc low plastic soils.

27

Fig. 2.11 Effect of lime content 011 AHerherg limits of a silty clay soil reported

from Ahmed (1984).

1210B6

Lime Content (%)

2

>-...,,~

-

-_._---.--...-t:::\ -0- UqUd lIrr11 -•.••.•..••.•.. -0- P14s1iclimit~ -b- P1asdclly Index--

t--

oo

10

40

50

Heavy clay[,n,halmQlSlur. conlanl 26'1'.)

7r .:> 0 days+ 3 dayso 6 daysx 28d.V.

5~.

Silly clay(inilial moisture content -18%)A 0 daysA 26 days

012345676L.me conlenl (%)

Fig. 2.12 Influence of lime conlcnt on the linear shrinkage of clays afler Bell (1988)

2.4.2 Specific gravity

The specific gravity of any substance is defined as the unit weight of the

material divided by the unit weight of distilled water at 4°c. Due to addition of lime,

specific gravity changes. Brandl (1981) stated that changes of specific gravity are time

dependent, which indicates long-term transformations of the chemical bound water and

the gel; the formation of new minerals is responsible too.

The change of specific gravity arc presented for in Fig 2.13, Which shows that

for inactive soil i.e. silts A-4 [symbol used was solid circle (-._), sand 15%, silt 73%,

clay 12%] specific gravity initially increases with the increases of lime content, but

after 2.5% lime colitent it starts decreasing with the increasing lime. But for active soil

i.e. clay A-7-6 [symbol used were, open circle (-0-), sand 21%, silt 54%, clay 25%]

specific gravity always almost decreases with the increases lime content. In case of

active soil, the specific gravity is further affected by the curing time, That is, with the

increases of curing time, specific gravity significantly decreased.

28

~ !gjcm3]

2,7/.

2.72

2)0

2,68

1.0 2.5 5.0 7.5

Lime %Fig. 2.13 Variation of Specific gravity with lime content after Brandl (1981);Reaction time (curing

age) in days as parameter (drawn in rectangle): period from stabilization till test performance.

Where y, is the specific gravity

2.4.3 Permeability

Permeability is the property of soil, which permits the passage of water through

its interconnected void space. Townscnd and Klyn (1970) pointed out that the

permeability of soil increases due to addition of lime. While conducting the experiment

with heavy clay, they observed a marked increase in permeability, while for silty clay,

erratic or no change of permeability was observed. Broms and Boman (1977) show that

the addition of lime usually increases the permeability of soft clay. The increase in

permeability is associated with nocculation, where larger pore between the nocks

enables the nuid to now more readily in between the clay and corresponding change ingrain size distribution.

Variation of permeability with lime stabilized soil with lime percent for

different curing period as presented by Brandl (1981) is shown in Fig 2.14. From the

figure, it can be seen that the permeability for silt A-4 (symbol used were, solid circle

(-0-), (sand 15%, silt 73%, clay 12%) increases with lime upto 1% lime content andthen decreases.

29

7.5

k {em/sec}

"".~.~~

1.0 2.5 5.0Lime %

2. fO-7

Fig 2.14 Alteration of Permeability coefficients b)' lidding lime; reaction lime (curing age) indays as parameter (drawn in rectangle): period from stabilization 011 tcst performanceaner IJrandl (1981).

Where, k~ water permeability, em/sec.

Brandl (1981) pointed out (Fig. 2.14) that the more cohesive and more reactive

the untreated soil is, the more inercascs the permeability of the mixtures according to

the immediate flocculation. The maxima are gained at lime content between I% for

inactive silts to 10% for active clays. He also pointed that the change of permeability

over one or two decimal cxponent is easily possible. He also pointed out that with

increasing curing time the mineral particles are cemented within the soil lime mixtures.

The finc skeleton is embedded partly within a gelatinous intermediatc mass; hardcning

products of the binder grows into the voids of the soil aggregates changing the void

structure. Additionally, the stabilized soil grains surround themselves with a wider film

of bound water in a way that finally. the remaining void space bccomes smaller andthus the permeability decreases with curing time marching on.

30

2.4.4 Compressibility

Compressibility is the property of the soil of resisting deformation due to the

applied load upon it. In principle, the optimum water content increases, thus the

compactibility is eased. Only when the soil lime mixtures remain uncompacted and if it

is able to carbonate, the contrary effect happens because the coagulating particles

behave like 'sandy' grains. The proctor density decreases after adding lime Brandl

(1981). The results are shown in Fig. 2.15.

[The symbol used were, open circle (-0-), clay A-7-6 (sand 21%, silt 54%, clay 25%);

solid circle (-0-), silt A4 (sand 15%, silt 73%, clay 12%); solid triangle (-T-), silt A-4

(clay A-6), sand 30%, silt 48%, clay 22%]

15

w"" Proctor 1%/

(7

(51.0 2.5 5.0 7.5

Lime %

td ProctorIg/cm]/

1.0 2.5 5.0 7.5

Fig. 2.15 Alteration of optimum water content at proctor density after Brandl (1981).

where, wopt = Optimum water content at proctor density;

Ad= Proctor density

Broms and Boman (1977) stated that the lime-stabilized soil is normally firm to

hard and the texture is grainy. It has a low compressibility compared with untreated

soil. Broms (1984) also obsorbed that the deformation and strength properties of the

lime-stabilized soil are same as those of heavily consolidated stiff fiSSUred clay in thedesiccated dry zone.

31

CHAPTER THREE

Laboratory Investigation

3.1 General

As mentioned earlier, the permeability of soil depends upon various factors,

such as size and shape of the particle, particle orientation, temperature of liquid, soil

compaction, etc. In addition to this, permeability of lime treated soil depends on lime

types, lime content, procedure of mixing, curing time (reaction time) and procedure of

curing, etc. The main objective of this research is to investigate the influence on

permeability of lime treated soil of lime content, reaction time, etc.

Three types of soils were used for this research work. The soils were collected

from Bolurana, Anwara, Chittagong (soil type-I), Toraghat, Manikgonj (soil type-2)

and Farmgate, Dhaka (soil type-3). The site locations arc shown in Fig 3.1. Soil

sampling was carried out as per procedure (ASTM 0420-87). For each location,

approximately 1.5m x 1.5m area was excavated to a depth 1.5m by shovels. Proper care

was taken to remove any loose materials, debris and vegetation from the bottom of the

excavated pit. All disturbed sample were packed in a large polythene bags and were

covered by gunny bags and were eventually transported to the Geotechnical

Engineering Laboratory ofBUET, Dhaka.

All the soils were fine-grained, that is, about 90 to 95% materials of each soil

were smaller than 0.5 mm size. Of them, soils I and 2 were sandy soils and soil-3 was a

clayey soil. In this research, lime content was varied up to 5%, while the reaction time

was varied up to 14 days. Note that reaction time was defined as the time span passed

after mixing lime and water with sand or clay for the purpose of hydration to complete.

3.2. Test Programme

All the soils were treated with lime in percentage (by weight) of 1%, 3% and

5%. Permeability tests on various lime treated samples were done at various reaction

times. Tests on each type soil consisted of the following works in sequence, such as the

collection of lime from market and soil from the field, prepare both lime and soil for

32

mixing, mixing lime and soil at the definite proportion, watering, thorough mixing,

leaving the mixture at room temperature for a period (defined earlier as the reaction

time) to complete hydration, making test specimens of the required size and finally,

subjected the specimen to permeability determination testing. The entire work is shown

sequentially in a flow diagram in Fig. 3.2.The whole laboratory test program consisted

of carrying out the following tests on the three soils (Table 3.1):

a) Routine tests, such as grain size distribution and specific gravity tests on three

types of soil were performed in the laboratory to classify the soil. Atterbcrg

limit tests were done for the clayey soil.

b) Falling head permeability tests were performed for soil type-I and 2.

Permeability was determined at 4 day (for soil type -1),5 day (for soil type -2),

8 day (for soil type I and 2) day and 14 day (for soil type I and 2) reaction time

following procedure ASTM 02434-68. To confirm the repeatability of sample

preparation (on which permeability depends significantly), two samples were

prepared with similar testing conditions (i.e. with the same lime content,

moisture content during mixing and the same reaction time).

c) Consolidation tests were performed for soil type-3 to determine its permeability.

Table 3.1 Detail of laboratory test performed on the three types of soils

Types of Test Sample No. of tests

Soil type-I Soil type-2 Soil type-3Sieve Analysis and Untreated I I IHydrometer Test Treated - - -Specific Gravity Untreated 6 6 6

Treated 9 9 9Permeability test Untreated 3 3 -(Short time) Treated 18 18 -Permeability test Untreated I I -(Long time) Untreated 3 3 -Consolidation tcst Untreated - - I

Untreated - - 3

33

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Fig. 3.2 Flow Chart of the experimental work

Total Work

Collection oflime

Collection of soilsample

Lime prepared forsoil treatment

Soil prepared forlime treatment

SoilClassification

Soil lime dry mixture at the definite percentages of lime

Adding water

Mixed sample left for hydration

Test specimen preparation

Falling head permeabilitytest (for soil type land 2)

Presentation of the Work

35

Consolidation test(For soil type-3)

3.3 Material used

The test materials used are described bellow.

3.3.1 Soils

As mentioned earlier, three types of soil were selected for investigation. The

grain size distribution of three soils is given in Fig. 3.3. The different fractions of sand,

silt and clay of soil-I were 96%, 4% and 0%, respectively and those for soil-2 were

99%, I%, and 0%, respectively. These fractions were obtained according to MIT

Textural Classification (1931). According to unified (ASTM 02487) and AASHTO

(M 145-66) soil classification, the soil were fallen into the groups SP-SM and A-3, SP

and A-3, respectively. Table 3.2 shows different properties of the soil.

Soil type-l: As mentioned earlier, this soil was collected from Anwara, Chittagong at a

depth I.5m below the existing ground level. It was fine sand with FM=0.26 010=0.075

mm, D50= 0.11 mm, G,= 2.69, Fine content, defined as material passing through #200

sieve, was 8%.

Soil type-2: This soil was collected from Toraghat, Manikgonj at a depth 1.5 below the

existing ground level. It was a local sand, generally used in building construction.

Physical properties of the sand were: FM=1.29, DIO=0.15 mm, 050= 0.26 mm, G,=

2.72, Fine content passing through #200 sieve was 1%.

Soil type-3: This soil was collected from Farmgate, Dhaka from a depth 1.5 below the

existing ground level. It was typical Dhaka clay (reddish). Basic properties of this soil

were G,=2.74, LL=50.1%, PL=II%, and cc=O.ll (using reconstituted sample). The

optimum moisture content using standard proctor energy was 15.3% and the

corresponding dry density was 15.49 kN / cU.m. According to MIT classification, the

clay was consisted of 10.5% sand, 39.4% silt and 50.1 % clay (Fig. 3.3).

Specific gravity (G,) of untreated soils can be available in Fig. 3.4, when lime

content was 0%. In the same figure, G, was also plotted for various lime-treated soils. It

can be seen that due to lime treatment, the value ofG, changed slightly.

36

Table 3.2 Physical properties of the soil used for lime treatmeut

Properties of the soil Soil Type- I Soil Type-2 Soil Type-3

Textural composition

Sand %(2mm to 0.06) 96.0 99.0 10.5Silt % (0.06 mm to 0.002) 4.0 1.0 39.4Clay %<0.002 - - 50.1Specific Gravity 2.69 2.72 2.74Classification

Unified (ASTM-1976) SP-SM SP CHAASHTO (1993) A-3 A-3 A-7-6 (13)

3.3.2 Lime

Lime used for soil treatments were collected from open market. It was kept

sealed to prevent carbonation until immediately before use. Chemical analysis reported

by Mollah (1997) was one of the commercially available lime in Bangladesh, which is

presented in table 3.3. Note that in this research, chemical analysis of the lime used was

not done. Market survey showed that apparently similar types of lime are commercially

available in the market. It was assumed that it would have similar constituents asMollah (1997).

Table 3.3 Constituents of lime from chemical analysis after Mollah (1997)

Name of the ingredient Quantity of ingredient (%)CaO 48.72MgO 17.60Fe, AI, Na, K etc. 8.18SiO, 1.80*Ioss dueto ignition 23.7

'The loss on inanition is due to the removal of water from Ca(OH), and Mg(OH),.

37

Soil-3; clay

Sand= 10.5%; Silt= 39.4%; Clay= 50.1%MIT classification

100

80

20

o

10

5011-2

DlD= 0.15 mm, 0'11= 0.26 mm#200~ -I %; FM~ 1.29

0.1Particle Size (mm)

0.01

:":":":' ':"' .•...... :--.

::-: ..•._-;

j:::i',.j:::I::'j,"

IE-3

Fig. 3.3: Grain size distribution of untreated soils.

38

2.80

2.75

o.~"0 2.70~

2.65

2.60

-o-Soil-I--{]- Soil-2-t:>- Soil-3

o 2

Lime content (%)

4 6

,.. """ ....

Fig. 3.4: Specific gravity of soils at different lime content

39

3.3.3. Water

Tap water was used for mixing and testing purpose.

3.4 State variables

The permeability of lime treated soil, change with the state variable. Those of

the different variable used in this research are presented below.

3.4.1 Soil: Three soils as mentioned earlier, were used throughout the test to investigate

the effects of soil type on the permeability oflime-treated soil.

3.4.2 Lime content: Commercial limes as available at the local open market were used

in the test program. Permeability of the lime treated soils was determined at 1%, 3%

and 5% lime content.

3.4.3 Reaction time: Reaction time is the time interval between wet mixing' and

preparation of sample for test. This time was allowed before testing to occur reaction

and hydration of lime. After thorough mixing, soil lime mixture were again mixed with

20-25% (by weight) of tap water. The water quantity was such that it is sufficient to

wet the soil particle but not excess which might cause the lime to wash out from the

soil grain. The samples (soil type I and 2) were then left over a watertight table to

complete reaction in room temperature. The samples for soil type I and 2 were then

tested after 4 day (for soil type-I), 5 day (for soiltype-2), 8 day (for soil type land 2)

and 14 days (for soil type I and 2). In the case of soil type 3, soil sample mixed in the

same procedure and kept in airtight polythene bag in a sealed condition and subjected

to consolidation test after 3 days of mixing.

3.4.4. Compaction energy: The apparatus for falling head permeability test was such

that the application of larger load could not be possible. To confirm the repeatability of

sample preparation and to obtain test specimens of same density (and hence same void

ratio), one-kilogram weight load was applied on the soil specimen for the purpose of

compaction during reconstitution. However, this additional load was applied only on

sandy soils during reconstitution in the permeameter.

40

3.5 Preparation of the lime-treated soil specimen

Untreated soils type- I, type-2 and type-3 were first air-dried and the lumps were

broken by wooden hammer. The soil was then passed through sieve # 4. All the

materials retained on this sieve were then discarded. Then the representative soil

sample of required quantity was taken for oven dry. After oven drying for 24 hours, the

soil sample was cooled naturally and lime of predetermined percentages was then

added. The percentage of lime, calculated on the basis of oven dry weight of the soil

sample, was varied 1%, 3% and 5% in each soil. The soil and lime were thoroughly

mixed until the color became uniform. Then water was added and the mixture was

thoroughly blended with 20-25% (on weight basis) water. Attention was paid not to

mix excess water that might cause the lime to wash out from the soil grain. The

percentage of water content was so selected as to complete maximum hydration as

possible during reaction time. The soil-mass was then kept on a watertight platform for

reaction to occurs in the case of soil type I and 2, while for soil-3, the sample was keepin an airtight polythene bag.

Preparation of the soil sample for permeability tests

The lime treated soils (for soil type I and 2) after the reaction time of

designated period become globular and formed weak bonded lumps. They were

collected and thoroughly broken by using wooden hammer. Test specimen for Iime-

treated sandy soils and also for untreated sandy soils was 63.5 mm diameter and

IOOmm height. Each specimen was prepared in the permeameter immediately before

testing. One complete specimen was prepared in 5 steps, each consisted of 20mm

height. In each step, the hydrated lime-treated or untreated soil was poured into the

permeameter in the required quantity using a spoon. A metal disc of size similar to the

upper porous stone backed by a spring of sufficient strength was inserted into the

permeameter and was placed on to the soil-mass. Then an additional load of weighing I

kg was applied on the spring so that the load was applied on the soil-mass poured into

the permeameter. The load so imposed was kept for 5 minutes, after which the required

compaction was assumed to complete. After that the load and the spring attached metal

disc was removed. Soil-mass was poured as before for the 2nd steps, which was

41

followed by loading and compaction, and so on. After completing 5 steps in this

manner, the test specimen was said to be ready for testing.

For the case of soil type-3, lime-treated clay soil was collected from polythene

bags after three-day reaction time. Lumps were broken and were compacted following

procedure ASTM D 698-70 in a 100mm diameter compaction mould by 25 nos. of

blow in three layer with 5 Ibs hammer dropping from a height of 0.75m. The 63.5mm

diameter and 25.4mm thick soil sample was extracted from the middle part of the

mould following procedure ASTM D 2435-70. Note that the clay soil was reconstituted

at a moisture content above standard Proctor density (i.e., which was varied in the

range between 20% and 25%. Both treated and untreated clay was initially mixed with

this moisture content and left the mixture for 3 days. During this period, hydration

occurred in case of lime treated clay, but for untreated clay, the time was sacrificed so

as to attain a similar state / stage with respect to moisture before the actual

consolidation test was commencing.

Different relation used for calculation purposes.

For the calculation of void ratio of soil type J and 2 the following relation is used.

Permeability of soil sample I and 2 are determined from relation 3.2.

k - & In.."L- At ", •.••..••..••••..••..••••..•• (3.2)

e G,;'Y, I (3.1)w.Where W, is the dry weight of the soil grain and is calculated by the difference

between air-dry sample weight and moisture content at the stage of testing and VTis thetotal volume of soil.

a= Cross sectional area of the stand pipe

A= Cross sectional area of the soil sample.

h,= Hydraulic head across sample at beginning of the test.

h,= Hydraulic head across sample at end of the test.

L= Length of the soil sample.

42

Where

Viscosity of water was corrected from the following equation

Iso = kT ;;,. .Where 11= Viscosity of fluid (water)

For soil type-3

Compression Index,

C = d.eC d(loglO P)

Coefficient of compressibility,

0.435 Cca = ----'-V Pay

.. (3.3)

........... (3.4)

.......... (3.5)

Where p" = Average pressure for the increment.

Coefficient of Permeability,

Where H= Average length of the longest drainage path during the given load.

t50= Time for 50% consolidation in minute.

k=

and coefficient of consolidation,

_ O.197H'Cv - I"

43

.......... (3.6)

......... (3.7)

CHAPTER FOURResults and Discussions

4.1. General

Penneability of three different re-constructed soils (two sandy and a clay soil)

was treated in the laboratory to investigate the effect of lime treatment. The soils were

treated by using lime of different percentages (e.g. 1%, 3%, and 5%). Soils 1 and 2

were cohesion-less, so penneability of these soils was detennined by using falling head

method. For the case of soil sample-3 (clayey soil), consolidation test was perfonned to

evaluate its penneability. The tests were performed on the treated samples at 4 day (for

soil type-I), 5 day (for soil type-2), 8 day (for soil 1 and 2) and 14 day (for soil I and 2)

after mixing and subsequently cured for reaction to occur in air-dry state (the curing

period was defined earlier as the reaction time). The reaction time was 3 days after thereconstitution of clay soil.

4.2. Test results and discussions

Laboratory tests were perfonned to investigate the effects of lime content, and

reaction time (after mixing) on the permeability of lime-treated two sandy and a clayey

soils. The samples were reconstituted in the laboratory. Since penneability of a lime

treated soil is very sensitive to void ratio, soil fabric and structure, aging after

reconstitution, stress level, etc., attention was given to maintain these controlling

factors unchanged among the tests except the lime content and aging (which was

tenned as the reaction time). To check the repeatability of test samples, two samples

were prepared with the similar testing conditions (i.e. with the same lime content,

moisture content during mixing and the same reaction time). After testing, it was

observed that although testing conditions were similar, both void ratio and penneability

were varied noticeably. Figure 4.la shows such test results in which void ratio in

observation I was plotted against that obtained in observation 2. Although a 1:I

relationship (which confinns repeatability) was not observed, the data were not

deviated from I: 1 line significantly. Similar results can be observed from Fig. 4.1bwhen permeability was plotted in the identical fashion of Fig. 4.1a.

44

Average penneability and void ratio were calculated from the test results of

samples subjected to similar test conditions and are summarized in Table 4.1. Other

results related to this table will be discussed later. In the following discussion, the

average values of the test results for soil type I and 2 were used. It was already

mentioned that for a given soil, various percentages of lime were used for the

investigation and besides, for a given percentage of lime content, the reaction time was

also varied (up to 14 days).

For soil type-3, consolidation test results were plotted in the Appendix. The

relationships between dial reading and time were shown in Fig. A4.1 for 0% lime

(untreated soil), Fig. A4.2 for I% lime content, Fig. A4.3 for 3% lime and Fig. A4.4 for

5% lime content. Each test was performed for load-steps 6.25 kPa, 12.5kPa, 25.0 kPa,

50.0 kPa, 100.0 kPa, 200.0 kPa, 400.0 kPa and 800.0 kPa. From each plot of dial

reading vs. time (Fig. A4.1 to A4.4), the values of t50 for each curve were detennined

and the corresponding values of Cv were detennined using Eq. 3.7. Log-pressure versus

instantaneous void ratio was plotted in Fig. A4.5. From the above curve, the value of

compression index (ce) was determined as the slope of the recession part (linear) of the

curve and the value of coefficient of compressibility (av) was detennined by using Eq.

3.5. From the evaluated values of Cv and av, the permeability within the particular

loading range was detennined using Eq. 4.6 and are summarized in Table 4.2. The

relationships between the coefficient of penneability and the lime content were shown

in Fig. 4.2 for different load ranges. The same data were plotted to observe the

relationships between penneability and load range in Fig. 4.3. In the latter plot, the

similar relationships were plotted for lime content 0%, 1%, 3% and 5%. The following

trends of behavior can be seen from these figures (Figs. 4.2 and 4.3): a) the coefficient

of penneability was maximum at about I% lime content (which was at least 5 times the

permeability value for the untreated soil) while the penneability was smaller for lime

contents both greater and smaller than 1%; b) the coefficient of penneability had a

decreasing tendency with the increase of vertical pressure, which was quite obvious; c)

at about 3-5% lime content, the coefficient of penneability was little sensitive to theapplied pressures.

45

Figures 4.4 through 4.8 show the results obtained by performing permeability

tests (falling-head test) on cohesion-less soils. As mentioned earlier, two different

cohesion-less soils -soil type- I (a fine sand with FM=O.26) and soil type-2 (relatively

coarser sand with FM=I.29) -were used for this purpose. Test variables were lime

content varying from 0 to 5% and reaction time varying from 4 to 14 days. Figure 4.4a

and b show the relationships (e-Lc) between void ratio (e) and lime content (Lc)

obtained from soil I and 2, respectively. In the same plots, such e-Lc relationships

were plotted for different reaction time. In calculating the void ratio, the specific

gravity (Gs) used was not constant for different test samples (although the base soil was

the same), which could be due to the change of lime content (see Fig. 3.3). However,

the change was very small. The following behavior can be observed from Fig. 4.4a and

b: (I) for fine sand (Fig. 4.4a), void ratio increased with the increase of Lc up to about

3%, at which the value of e was the maximum; the rate of change of void ratio

decreased slightly for Lc.> 3%; (ii) For relatively coarse sand (Fig. 4.4b), the void ratio

decreased with the increase of Lc while the rate of decrease was large up to I _ 2% of

Lc, beyond which the rate became small. The difference in behavior of these two

cohesion less soils could be due to the difference in their grain size characteristics. It

seems that fines or the smaller particles have significant influence in the lime treated

cohesion-less soil. If such particles are present significantly, the addition of lime

increased their effective sizes (probably, due to coagulation) and hence increased the

void ratio. On the 'other hand, if these particles are absent (or present in small amount),

the presence of lime cannot coagulate the dominating 'larger' particles; rather they

reduce the voids between the larger particles effectively coagulating with fine particles

(which are small in proportion). As a result the void ratio decreases.

However, this increase or decrease in void ratio was not proportionate with

permeability (Fig. 4.5a and b). For example, in case of soil-I void ratio was increased

up to 1.5 times at Lc=3 % compared to that was when Lc=O% (Fig. 4.4a). For this, it

was expected that the permeability would be increased at least 2 times at Lc= 3%

compared to when it was for Lc= 0 %, because it is known that permeability of

cohesion-less soil is proportional to the square of the mean particle diameter 0'0 (i.e.,

k = CD,," Eq. 2.1, where C being a proportionality constant). But for soil-2 (Fig.

4.5b), on the other hand, the decrease in permeability with the increasing Lc was

46

consistent with the decrease in void ratio. The data of Figs. 4.4a were re-plotted in Figs

4.6a and b, respectively, to show the relationships between void ratio and reaction time,

and the permeability and reaction time. Similar data from Fig. 4.4b (of soil-2) were

plotted in Fig. 4.7a and b, respectively. In all the figures (Figs. 4.6-4.7), the respective

variationl relationships were plotted for different Lc. Note that the relationships

corresponding to Lc= 0 % were for the untreated soils. The following trends of

behaviour can be observed from the above relationships: (a) both void ratio and

permeability were insensitive to the age of the untreated sample (here the term reaction

time is not valid for untreated soil); (b) void ratio decreased with reaction time slightly

for both soil-l and soil-2; (c) with the decreasing tendency of void ratio with increasing

reaction time, soil-l exhibited insensitiveness in the change of permeability while

permeability of soil-2 was decreased accordingly. This difference in behavior of the

two cohesion-less soils could be due to the role of fine content (as described earlier).

Long-term stability of permeability of lime treated sands (soil I and 2) were

investigated. For this purpose, after certain days of reaction time, the permeability of

the treated soil was determined (following the same procedure as stated before)

intermittently during a span of 30 to 40 hours. The reaction time allowed before this

investigation was 4 days to 14 days for both sandy soils. Lime content for Soil- I and

SoiI-2 was 5%. The relationships between the permeability and the elapsed time

showing the long-term stability of permeability are shown in Figs. 4.8a and b. Although

some scatters can'be observed in data, the permeability of lime treated sands was more-

or-less stable throughout the investigating period.

All the permeability data for lime treated sands (Soil-I and Soil-2) shown in

Figs. 4.4 through 4.5 were plotted against the void ratio (e) in Figs. 4.9a and b,

respectively, for Soil-I and Soil-2. The data were plotted disregarding the lime content

of the individual specimen. In the same figures, the permeability data were also plotted

against the functional value of a void ratio function f(e)= eJ/(l+e). Note that many~C'il

authors shown that the permeability of a cohesion less is proportional to a void ratio

function fee) passing through the origin (Fig. 2.3 after Das, 1983). Among many other

void ratio functions, the commonly used one is f(e)= eJ/(l +e). The following trends of

behavior can be observed from Figs. 4.9a and b: (i) like untreated cohesion less soil, the

47

48

penneability of lime treated sandy soil was Proportional to its void ratio and a void

ratio function, (ii) although the permeability was proportional to the functional value of

the void ratio function fee), the linear relationship did not pass through the origin; rather

it exhibited an offset on the void ratio function axis denoting a range of void ratio ( and

hence a range of the corresponding functional value) up to which the lime treated sand

would show 'no Or very little' permeability; (iii) the 'no penneability' range of the void

ratio functional value was larger (>0.50) in fine sand than that was (=0.20) in the

coarser sand ( which was also a fine sand by definition of FM). The above discussion

reveals that the same void ratio function, which is applicable for a cohesion less soil,may not be applicable for the same soil after the lime treatment.

Table 4.1: Some test results from soil 1 and 2 (Sandy soils)

LimeSoil Type-1

Soil type-2Content Reaction Void Penneability Reaction Void PenneabilityTime ratio (x JO'3) time ratio (x 10.3)(day)em/sec (day)

em/sec0% - 0.9896 2.519 - 1.0290 10.3551% 4 1.1871 3. J 19 5 0.9832 9.3398 I. 131 2.747 8 0.9476 8.98014 1.0573 2.627 14 0.890 8.1 J 93% 4 1.2832 3.492 5 0.8626 6.2658 1.2125 2.781 8 0.8389 5.46614 1.0412 3.119 14 0.8096 5.3555% 4 1.236/ 3.262 5 0.8350 3.9948 1.2095 3.168 8 0.8082 3.69814 I. 1339 2.802 14 0.7932 2.861

Table 4.2: Some test results from soil type-3

Lime Load .Cy ay(x 10") Yw Void ckT= k20(x 10")Content

kPa sq.cml kPa.J gm/cc ratio '7, 1'7,. cm/sec

min (e)

5% 0.0 - 6.25 0.9957 - 0.7967 0.0

200.0 0.0525 6.25 1.04584 7.628

400.0 0.0781 6.25 1.03571 9.132

800.0 0.0465 6.25 1.01059 6.882

3% 0.0 - 4.35 0.9957 - 0.7967 0.0

200.0 0.0787 4.35 0.7865 9.125

400.0 0.0783 4.35 0.7801 9.106

800.0 0.6714 4.35 0.7614 7.889

1% 0.0 - - 0.9957 - 0.7967 0.0

100.0 0.0414 10.282 0.7653 34.24

200.0 0.0493 10.282 0.7323 18.762

400.0 0.0664 10.282 0.6922 14.278

800.0 0.1234 10.282 0.6546 12.258

0% 0.0 - - 0.9957 - 0.7967 0.0

100.0 0.0249 7.909 0.6704 5.607

200.0 0.0134 7.909 0.6322 3.079

400.0 0.1284 7.909 0.6042 3.013

800.0 0.0195 7.909 0.5768 4.653

fKT= Absolute or kinematics fluid viscosity correction factor (at average temperature 30oe)

49

rllI' •••••.••••••••,•••

1.501.251.000.75

;;;;;;;

: ! : j . 0'-'_.-'-'-'T-._.-'-'-'_._J_._._._._._._.L_._._'-'-'-.i-'-'_._'-'-'_~D_.n._.-

. i ' i ' 0j ii i••••••••• 1 •••• - ••••••••• r- ..

, ! ' ~._._. _._._.~._._. _._._._-- J_._._._._._._.7" O' _0. _._._._._._. ._._._._._._.,.._._._._._._._._._._._._. .

, '0 ;i 0: 0 i! 0 !,-.....0 .!." ,,0 0 L.! DOlQ " ;! 0°: ! : f i._.-.-._._ ..•-_.-._._._._. ._.-._._.-.(l~._._._. -. _._.-!. --_._._-_._._ •••._._._._._._. -1.._. _. _._._._._;_._._._._._._., ' ,n i jr i iiiii i ~-.. . i-.j ! !j I I

! j j

1.50

1.25

1.00

0.75

0.500.50

-a]o.5o.~"0

~

Void ratio in observation 2

Fig, 4.1 a: Relationship of void ratios between two observations under otherwise similar test conditions for soil. 1

Fig. 4.1 b: Relationship of permeability between two observations under otherwise similar test conditions for soil-2

50

12963

Observation 2: Penneability (x 10-3) cm/s

oo

12'"Eu

'b- 9><~.f':.E'""E 6"p..c0.~

31:"'".00

25Clay soil

20 vertical stress (kPa)-0-200-0-400---l;-800

oo 2

Lime content(%)4 6

Fig. 4.2: Relationships between penneability and lime content for soil-3

25

__-------00>--------.-<0-

800

Lime content-0--0%-0-1%----6-3%~5%

600Vertical stress (kPa)

400

iii

Fig. 4.3: Relationships between penneability and vertical load for soil-3

200o

5

15

20

10

1.6

o.~'"0 1.2~

Reaction time--0-4 day..--0-8 .day.--I:r- 14 day

0.8a 2

Lime content (%)4 6

1.2

Fig. 4.4a: Relationships between void ratio and lime content for soil. I

1.0

0.8

0.6a 2

Lime content (%)

4

Reaction time=<>=5 'day-0-8 [day-6-14day

6

Fig. 4.4b: Relationships between void ratio and lime content for soil.2

5Z

6

Reaction time

'" 4au

'b-><~.£:.0 2'""E"0..

oo 2 4 6

Lime content (%)

Fig. 4.5a: Relationships between penneability and lime content for soli-I

642oo

12

Reaction time

'"-{)-5:day

a 9--a-8day

u -fr.- day

'b-><~.£ 6:.0'""E"0..

3

Lime content (%)

Fig. 4.5b: Relationships between penneability and lime content for soll-2

53

1.4

.1.2

1.0

0.8

Lime content--0%-0--1%-0--3%---t::r-5%

4 8 12Reaction time (day)

16

6

o

Fig. 4.6a: Relationships between void ratio and reaction time for soil-I

Lime content---0%'---<>-1%-0-3%-b-5%

4 8

Reaction time (day)

12 16

Fig. 4.6b: Relationships between permeability and reaction time for soil-I

54

o.'@"0.0;>

1.2

1.0

0.8

0.64 8 12

Reaction time (day)

Lime content--0%-0-1%-0-3%--6--5%

16

Fig. 4.7a;' Relationships between void ratio and reaction time for soil.2

Lime content15---0%-0-1%

-0--3%12 ----6-5%

~u.r 90-:<~.€

6:.0"<1>

E<1>Q.,

3

o4 8

Reaction time (day)

12 16

Fig. 4.7b: Relationships between permeability and reaction time for 50il-2

!l5

4Soil-ILc=5%

Ula 3u~

'b><~.q:0'" 2'"E'"P..

Reaction time (day)-0--4---{}--- 8

-6---14

~~"- -::::::::========-8

o 10 20Time (hour)

30

Fig. 4.8a: Long-tenn penneability after different reaction lime for soil-I

4

40

Reaction time (day)-0--5-0--8-6--- 14

3020

56

Time (hour)

10

Soil-2Lc=5%

Fig. 4.8b: Long-term penneability after different reaction lime of soil-2

o

3

2

3.60 e-k •• 0

3.4 - • f(e)-kJf(e)= e /(I+e)

•• 0

~ 3.2 -0•u • •• 0 0~

>< 3.0 -g:E /-'""E 2.8 t- :. • 0 0"0.- • 0

No permeability zone• • ~ 02.6 - , • I • I I • I

0.00 0.25 0.50 0.75 1.00 1.25 1.50eorf(e)

Fig. 4.9a: Relationship between void ratio or fee) and permeability ofsoil-)

Fig. 4.9b: Relationship between void ratio or fee) and permeability ofsoil-2

57

oo

o

:.••• •

.' 0.~' DO

:. 0:. 0

•• 0

I ) I

0.4 0.6 0,8 1.0e or f(e)

,:0.20.0

o e-k9 - • f(e)-k

fee) = eJ/(J+e)

6 t-

CHAPTER FIVE

Conclusions and Recommendations for the future Research

5.1 General

In this research work, three soils were used after collecting from three

different locations to investigate permeability and its characteristics after lime

treatment. Soils were treated with lime at different percentages (I %, 3%, and 5%).

The tests were performed on air-dry sample after allowing different reaction time

(curing age). Soils I and 2 were cohesion-less and their permeability was determined

by using falling head method. On the other hand, soil-3 was cohesive one and so

consolidation test was performed to determine its permeability characteristics. After

mixing soil with lime at a definite proportion, a time (denoted earlier as reaction time)

was allowed for the reaction of lime to occur with water and soil particles. The

reaction time was varied from 4 to 14 days. Long-term stability of permeability of the

cohesion less soils was investigated after the elapse of certain days of reaction time.

The duration of long-term stability of permeability was 30 to 40 hours. In this period,

the permeability of a specimen (lime-treated) was determined intermittently. Overall

permeability of lime treated soil and its void ratio (irrespective of lime content) and

the functional values of a void ratio function f(e) were also investigated to check

whether they follow the same rule as those of the untreated soil condition.

5.2 Conclusions

The following conclusions can be drawn based on the results obtained after

investigating various aspects related to permeability characteristics of lime treatedsoils:

a). Overall increase in permeability of lime-treated clay was observed. But the

influence of lime content on permeability was not similar throughout the

investigated range of lime content. That is, the permeability was maximum for

58

the specimen treated with I% lime (at least 5 times of the untreated clay), but it

was not change noticeably in the range 3 to 5% lime.

b. Regarding to permeability characteristics, the cohesive soil was more sensitive

to lime content than cohesion less soil. In the investigated range of lime

treatment, the permeability of cohesive soil increased at least 5.0 times of its

untreated value, while the permeability of relatively fine-grained (FM=0.26,

fines = 8% passing through # 200 sieve) sand increased up to 1.3 times and the

'coarser' sand (FM=I.29, fines = 1%) decreased to 0.72 times of theirrespective untreated values.

c. Void ratio of lime-treated cohesion-less soils was influenced by the presence of

fines or small particles in sand. Sand (soil-I) with having substantial fines

exhibited an increasing tendency of void ratio with the increase of lime content,

while that with 'coarser' particles showed a decreasing tendency of void ratio

with the increase of lime content. The difference in behavior could be due to

the increase of the effective size of' finer' particles after coagulation with lime

particles resulting in larger voids in the interparticle spaces. As a result of this

particle rearrangement, void ratio configuration of the soil mass was increased.

However, in case of 'coarser' particle, such coagulation of lime particle and

'coarser' grains effectively reduced the interparticle spaces inside the soil massand subsequently reduced the void ratio.

d. Consistently with the void ratio pattern, the permeability of lime-treated sands

was also changed. That is, the decrease in void ratio was resulted in the

increase in permeability. However, the degree of change was not consistent

with that would occur in case of the untreated sand.

e. Aging had no affect on the permeability and void ratio of untreated sands. But the

void ratio and hence permeability of lime treated sand was slightly changedwith the reaction time.

59

f. The pemleability of lime treated sands (after the completion of certain period of

reaction time) was more-or-Iess stable throughout the investigation period of 40hours.

5.3 Recommendation for future study

It is recommended to extent the research work in the following field to have abetter understanding about lime-treated soils:

a) More similar soils should be investigated to obtain a general conclusion

based on the present findings.

b) Permeability characteristics can be investigated using the additives such as

cow-dung, fly ash separately or lime-cow-dung, lime-fly ash, fly ash-limecombinedly.

c) Various engineering properties including permeability of stabilized soils can

be investigated after the application of different compaction efforts such as

kneading, preloading, vibration, etc.

60

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Arman, A. H. and Muhfakh, G. A. (1972), "Lime stabilization of organic soils",Highway Research Board, Washington, D.C. HRB bul. no 381.

Arce, R. G. and Boyed, C. E. (1975), "Effects of Agricultural limestone on waterchemistry, phytoplankton productivity and fish production in soft-water ponds",Trans. Amer. Fish Soc., 104; 308-312.

BS 1377 (1975), Method of tests for Soils in Civil Engineering Purposes, BritishStandard Institution, Gaylard and Son Ltd, London.

Bell, F. G. (1988), Lime Stabilisation of Clay Soils, Part-I, Basic properties, GroundEngineering, vol. 21, NO.1 pp.10-15.

Boominathan, A. and Prasad, S. R. (1992), "Laboratory investigation ofeffectiveness of lime treatment in polluted soils", Proceedings of the IndianGeotechnical Conference, pp. 497-500.

Bowles, E. J. (1978), Engineering properties of soils and their measurements,Second Edition, McGraw- Hill, Inc.213p

Broms, B. (1984), "Lime-Clay mineral reaction products", Ontario Ministry ofTransportation and Research Report, RR243.

Brooms, B. and Boman, P. (1977), "Stabilization of soil with lime columns",Design Hand Book, Royal Institute of Technology.

Boyed, C. E. (1990), Water Quality in Ponds for Aquaculture, BirminghamPublishing Co. Birmingham, Alabama.

Boyed, C. E. and Scarsbrook, E. (1974), "Effects of Agricultural limestone onphytoplankton communities of fish ponds", Arch. Hydrobiology, pp336-349.

Bowling, M. L. (1962), "The effects of lime treatments on Benthos production inGeorgia farm pond", Proc. Annual Conf. S. E. Assoc. Game and Fish Comm., 16;418-424.

Brandl, H. (1981), "Alteration of soil parameters by stabilization with lime",Proceeding of the Tenth ICSMFE volJ. pp 587-594.

61

Bangladesh Transport Survey, (1974), "Basic Data- The Soils of Bangladesh, Part8, The Government of the People's Republic of Bangladesh.

Compendium (1987), "Lime stabilization, reactions, properties of design andconstruction", State of the art Report-5, U.S. Transportation Research Board,Washington D.C.

Casagrande, A. (1937), 'Seepage Through Dams, in "Contribution to soilmechanics 1925-1940", Boston Society of Civil Engineers, Boston, 295p.

Carman, P. E. (1956), "Flow of Gases Through Porous Media", Academic, NewYork.

Diamond, S. and Kawamura, M. (1974), "Soils stabilization for erosion control",Joint Highway Research project 74-12, Purdue University, West Lafayette, Indiana.

Diomond, S. and Kinter, E. F. (1965), "Mechanism of soil lime stabilization", AnInterpretive Review, High way Research Board, bul. no.92, pp 83-96.

Das, B. M. (1983), Advanced soil mechanics, International Edition, Hemispherepublishing corporation, New York. pp. 65-166.

Eades, J. L. and Grim, R. E. (1960), "Reaction of hydrated lime with pure clayminerals in soil stabilization", Highway Research Board, Washington D.C., bull. No.262, pp 5I -63.

Eades, J. I., Nichols, F. P. and Grim, R. H. (1962), "Foundation of new materialswith lime stabilization as proven by field experiments in Virginia", HighwayResearch Board, Washington D.C., pp. 31-39, bull. 335.

Ghos, R. M. (1987), "Properties of the lime for stabilization", Journal of theInstitution of Engineers (India), vol. 68, part C 12, pp307-313.

Haunsmann, M. R. (1990), "Engineering Principles of Ground Modification",McGraw- Hill Publishing Company, Singapore.

Hilt, G. H. and Davidson, D. T. (1960), "Soil lime mixture", Highway ResearchBoard, Washington D.C. bull no. 304. pp.99-138.

Hickling, C. F. (1962), Fish culture, Faber and Faber, London. 295p.

Hazen, A. (1892), "Some Physical properties of sands and gravels with specialreference to their use in filtration", 24th Annual Report, Massachusetts Stae Board ofHealth.

Ingles, O. G. and Metcalf, J. B. (1972), "Soil stabilization-Principles andPractice''', Butterworths Pty. limited, Australia.

62

IRC (Indian Road Congress) I973b, "Recommended design criteria for the use ofsoil-lime mixes in road construction", IRC High way Research Board: 51-1973, NewDelhi.

IRC (1976), "State of the Art: Lime-soil stabilization", Special report' IRC high wayresearch board, New Delhi.

Kezdi (1979), "Stabilization Earth Road Stabilization with Lime", Elsvier ScientificPublishing Company, New York. pp-163- 174.

Khan, M. J. (1989), "Effect of Fly Ash with lime and cement additive on theengineering behavior of soft Bangkok clay", M. Sc. Engineering, Thesis no. GT 89-Ib, Asian Institute of Technology, Bangkok.

Kulkarni G. J. (1977), Engineering materials, Start book service, Punna, India

Kozeny, J. (1927), "Ueber kapillare leitung des wassers in Boden", Wien, Akad.Wiss. vol. 136 part2a, p.271.

Kozeny, J. (1933), "Theorie und Berechnung der Brunnen", Wasserkr,Wasserwritsch., vol. 28, p.104.

Lambe, T. W. (1993), Soil testing for engineers, Fifth Wiley Eastern Reprint,4835/24 Ansari Road, Darya Ganj, New Delhi 110002. 165p.

Mateos, M. (1964), "Soil lime research at Iowa state University", Journal of the SoilMechanics and Foundation Engineering Division, ASCE vol. 90, pp.127-153.

Mateos, M. and Davidson, D. T. (1962), "Lime and fly ash mixes and some aspectof soil lime stabilization", Highway Research Board, Washington D.C., bull. No.335, pp. 40-64.

Metcalf, J. B. (1977), Soil stabilization principles and practice, Willy and sons, NewYork.

Mitchell, .J. K. and Hooper D. R. (1961), "Influence of time between mixing andcompaction on properties of lime stabilized expensive clay", Highway ResearchBoard, Washington D.C., bull. No. 304. pp. 14-31.

Mitchell, J. K. and Hooper D. R. and Campanella, R. G. (1965), "Permeability ofcompacted clay", J. soil Mech. Found. Div., ASCE, vol. 91, SM4, pp. 41-65.

Molla A. A. (1997), "Effect of compaction condition and state variable onengineering properties of the lime stabilized soil", M. Sc Engineering Thesis, BUETlibrary, M-209, BUET, Dhaka, Bangladesh.

Muskat, M. (1937), The flow of Homogeneous Fluids Through Porous Media,McGraw-Hill, New York.

63

Naasra (1986), A Guide to stabilization in Road Work, Sydney, Australia.

Naasra (1987), Pavement design, 'A guide to the structural design of road pavement,Fine press offset printing, Pty. Ltd, Australia.

Olsen, H. W. (1961), "Hydraulic flow through saturated clay", Sc. D. Thesis,Massachusetts Institute of Technology.

Olsen, H. W. (1962)' "Hydraulic flow through saturated clay", Proc. 9th Nat. Conf.on clay and clay Min. pp. 131-161.

Piesch, P. I. and Davidson, D. T. (1962), "Effect of lime on plasticity andcompressive strength of representative Iowa soils", Highway Research Board,Washington D.C, bull. no.335, pp.II-30.

Punmia, B. C. (1991), Soil Mechanics and Foundations, Laxmi Publications, 7/21,Ansri Road, Daryaganj, New Delhi. pp. 171-198.

Pamatmat, M. M. (1960), "The effects of basic slag and Agricultural lime stone onthe chemistry and productivity of fertilized ponds", M. S. Thesis, Auburn, Aia. 113p.

Rajbongshi, B. (1997), "A Study on cement and lime stabilized Chittagong coastalsoils for use in road construction", M. Sc Engineering Thesis, BVET Library, BVET,Dhaka, Bangladesh, M-207.

Rodriguez, A. R, Castillo, H. D. and Sowers, G. F. (1988), Soil Mechanics inHighway Engineering, Part-2. pp 751-755.

Sastry, M. V. B. and Rao, A. S. (1987), "Cinder Ash as soil stabilization", Journalof the Institution of Engineers (India), vo1.67; part-C 16. pp 316-321.

Serjuddin, M. (1992), "Chemical stabilization of Bangladeshi fine grain soils forimprovement of road construction", Proceedings of the Indian GeotechnicalConference, Calcutta vol. I. pp 223-226.

Singh, A. and Punmia, B. C. (1965), " A new laboratory compaction device and itscomparison with the proctor test" Highway Research News, No. I7,HRB, Washinton.

Thompson, R. M. (1966), "Shear strength and elastic properties of lime soilmixtures", Highway Research Board, Washington D. C. vol. No. 139, pp. 61-72.

Thompson, R. M. (1968), "Lime treated soil for pavement construction",Proceeding of the American Society of Civil Engineering, pp. 191-213.

Townsend D, L. and Klyn, T. W. (1970), "Durability of lime stabilized soil", Highway Research Board, Washington D.C. vol.315 pp. 81-89.

64

APPENDIX

100001000100101

850

845

840

825

820

815

0.1

Time in minutes

Fig. A4.1a Dial reading vs. time curve for soil type-3 ( 0% Lime; 6.25-50 kPa)

Clc'6~ 835

iOC

830

i

•--6.25 kPal i

1--12.5 kpa II ......- 25.0 kpa I1--+-50 kpa

I855

I i I II jill I I I I I I I ii' '111 I III/III I II' iI I I II

Ii !11TI. T : I . I

:- I : II mi! I 1111111 I I i' . , iT

i I: .! II i i II i,iiii 1:1 I 1'" III'; II' I ' I I

iii II~ I IIII!II I:' I I! I : i ill iii iii :

II ,. ,

! i I I I I" I

I:I II I ' I, i I I' , I '

I • I I I I I' ..•' , : I . I

IiI

: i, i'! i , I i I I III i : II I I ,I ' , .

. ,

Iii Ilill ! Illml I t ,i~ ,T I ! iii ,I , I' ,, i,

' i I r I i

II, Ii I I I I III '~;Iil 1I11I11 I' .

: I : I I I Ii I Ii , i,

i I : I T i If' il~ I 1/1/ I I,, I

I I ! ,,

II

I ,

I III I I 11/1111:-./ II i

I I /I I II I I! i

I

66

, I I iI I i I I i. II III, I 1 I I I ! ! i , II I I I I I I '. i I' I. ,I -. T[ , I Ii: ill ii, , ,II i: ii' , I, , , , II, ,I , I, I I I .I; i I Ii, I

I I I " :! II, - ':'-i-. I ~ I : I I I I, i. T I"r-ra~. ~ I' a--c-:-. I I I I

'I I, iii I J I I III I I iii : :,1 iii I

'"", " , :" I II'I"!I I I 'I" T I, !illll, III Iiii :il 1T ilill I Illilllli i III

• J 'I ' I I' i I T I I I II1I , ,I I II! I • I II I !II[ " . I I I I i [I II II I II: II I I I I i I il i Ii , , I.1 i II i II I I I , , I I

'li;il;1 i Iii II!II ilI ill I I ! ,

---100 kpa I

-+-200 kpa Ii-'-400 kpa ,

-+-800 kpa I

100001000100101Time in minutes

Fig. A4.1b Dial reading vs. time curve for 5011.3 (0% lime; 100.0 -800.0 kPa)

850

650

6000.1

700

800

Cl.E~ 750~iiii5

67

, I ! I i III/I III i II I, i I, II/II Ill! i

, ,

I I I ! ! "i I II [ i II II I iii!! I [ ! i, !!,: i I I III! i Ii I i J'I' I::; I

I "I i ; J I I I I ,! I:

'I J Iii ill I ! i' I' II ~III!i i

, 1'1 lJllll' I,,'I. ' ': I: I Ii'

-LUll!!! ,Jiil.! ii::JiI iii!!:! I i I! iii I ! Ii! i i

I I : ~ II I I I I : I , ! ! I I II, I iI Iii Ii: i ! III I! i,I !, i , 1 , I I I. .

'I ' Ii! i II!!! II I, i!I " i " 'II I, I! ! ! i i II iii I: iIII i I ! ! III! I II!

10000

865

860

I! 85510>, l:!:aI 11l, .•I ~it;i C 850,I

I! 845

8400.1 1

Time in minutes10 100

I! 'I

I,

1- II,.1 I! III i, I •

! I 11111;. j • i III i, I I I I Ii

I I' I'i , I I ',iI I', i, Il '

! I I I I !I! I,I, IIi I !!

1111,

1

1

1111,1I , III I1I1

1000

I I

I

III I11I II 'I I~' i I"

~

I1I1

I

;--6.25kPa

I,--12.5 kPa-'-25.0 kPa--50.0kPa

Fig.4.2a Dial reading vs. time curve for soil-3 (1% Lime; 6.25-50.0 kPa) ,

68

100001000100101

Time in minutes

Fig. A4.2b Dial reading vs. time curve for soil-3 (1% lime; 100.0-800.0 kPa )

i I 1111 I! I ' I I II --I ' I! iii ! I: III! II I, ,, ! I I i I ! II ' III:, : i I II Ii I

I I : II ,I I', ,

j :I ,

! II iI

I!I! iii I I i I :i I ,,

, , ,I I I

,,! i I!! I ; , I I' ,I III, i i I I , III ' I I, i ' • I1'1' I" ,i iii, I I ! III/I Ii

, II ,

! i !,I i ' : J ',

i i 1111,

I : II I' I

, I ,I

i II iI i I ! I i; i I i !,I ,

I III' i,

I I I ' .

I I i if I I,

: I I i ; i :

~ I i IIi i I Ii!,I I I

II II II IIII,

II

800

650

6000.1

Cl 750.5"'"E

I --100.0 kPa' i, -- 200.0 kPa II

850 r-----~-______ ;--'-400.0 kPa, I800.0 kPa I

III,

III

iii, C 700I

69

---- 6.25kPa--12.5 kPa--.- 25.0kPa" --+- 50.0kPa

II

II

IIIffil'!ijI,

I -1 -, III [ ,

I I I' 1'ft'

I! I: II , ,I I ! !

I I i 11

I III!

II

I r

'1i , Iill

I!

i

! I III II "!I ; rr',, 'II I;

! i j: I iii I+---.' ,. t

, i ! I 'I Ii I ! , I.i. ! II' i I, I I,

iTfffiI I,!' I 1'1 I. ,

I , ' I I I I' , , , I; Ii : ! : , !, ,

i Ii. /'

"

I iI r,i I

Iii I 'I I I i

834

833

832

828

829

'".E 831"0••eOJi5 830

8270.1 1 10 100 1000 10000

, Time in minutes II Fig. A4.3a Dial reading vs. time curve for soll-3 (3% Lime; 6.25-50.0 kPa) II

70

I Iii II I III I II

I ! iii III I I I IIIII I I Iii t,I , I I, I

I I II ! I:

: I i I I I i ' I I I !! I IIIII I I di! I ; ! I IIIill II I I ,

, "

Ii , I : II' I i

Ii i I I I II ! IIi I I

i ! II, I : . ~ ! I I

i-iii III I I! ' I ! I I i I I I

1 II I ,

I ' I i-j i III

I I I ! 1 :: : i i I ! '__ ,

, ! I

: I I I I: • I ! III: ' I i1 i

! i i II : I : II, I! i !-- 'I ! I' : I iii ' ! I I: 'I I!' I ' ' I Iii!: I 'I I IIi! '! i I Ii' I i i

I : ~

I I, i , , '! I!: Ii, ! i I T, ' I

, ,i I

,! i ! I i

!; I , , , ,I' •. ' i ,! ! I I,

i

i I Tt I I;

: i II i I Ii I,: I

, ,II i I

i , I I I, i I I II!, II I,i i i i'll' I,

I,

I I i IIIII I II III

IIIIIII I

830

825

820

815

Cl 810c:c::l 805~iUis 800

795

790

785

7800.1 1

Time In minutes

10 100 1000

---- 100.0 kPa--e- 200.0 kPa

--+- 400.0 kPa

I-+-800.0 kPa

10000

Fig. A4.3b Dial reading vs. time curve for soil-3( 3% lime; 100.0-800.0 kPa)

71

160

Time in minutes10000

---6.25 kPa

--12.5 kPa

'I llll~=25.0 kPa! : I 50.0 kPa

, I !

I I ! I II ! : I IiLLllli"II . I I'

I' ', ' I IiiIii! I!i I ! ! Ii

I ,I :'I : :' II

iii i 1111'I ' I I

I' "I : I !: ~ iii I Ii ,! I III,I Ii:

i I I 11['

LLJI I I!! i III illIf

1000

,--.1/CWi ; II i II III'_1 J

i

II

100101

mil I r I,"! !! ii/III" I "I ' " ,.

I :, ,, ,

I r I I ! I i I I

I ' i ' i 1/' I: :', i,: ! i ~ I;I I iii ! i I, !! I ':' i 1 , I! !

I ! ! I I' Iii1-1' I 'i I I I Ii I I

I I I I I II I I

I II I I I I I.I I ,I I I I I

161

162

165

166

1670.1

'"i ~ 163, .•

~g 164

Fig. A4.4a Dial reading vs. time curve for soil-3 (5% Lime; 6.25-50.0 kPa)

72

--100.0 kPaj

-- 200.0 kPa :,I III II I I

i I,III I I

-.- 400.0 kPa i,

I I I'! I -+- 800.0 kPa i

I iii 'I i I Ii ! ! I,.

i I II : I

111111 i ! 1IIII

j II I i i

i I i , i I II,! I I ! !I I I T i fl I 1 Illii:' I I 1111111

! :I . : I

i I; , ' 'I II: i ! " II , i I I I j Ii I I I• I . ; I I' I I Ii: I I i ! II I , j ! li!i , I II I I I iii:

II. , I .: I ' II! , I

I ' , ' iii ,i ! i ! i i I ! II ' II' j I I .

I I I . III I i ' Ii I: !i II i I I ', ! ' I . . ~ ; ! I:

II I IiI

I I,J I ' , i ! I I' i I. . I I I' ! I,i i II Ii II I II •...

I I 1--' I' i I IiI II I I I I Ii ! II !

I III 'I I

I I I

150

160

170

180Clc'i5e 190iiiC

200

210

220

2300.1 1

Time in minutes

10 100

\ ~~/

1000 10000

Fig. A4.4b Dial reading vs. time curve for soil-3 (5% Lime; 100.0 -800.0 kPa)

73

-"1.'

"1000

I !I, I

I1_, _

100

, ,I •

74

I

I i Iiii I '

I I i II III

Pressure (kpa) 10

Fig. A4.5 Void ratio vs. Log-pressure curve for soil type-3

0.41

1

0.9

.e 0.8-'"~"C'0> 0.7

0.6

0.5

I- ~-'-----, -+- 0% lime : !

i -'-1% lime I ,I -ftl~1

I -R~I' I,

1.1 'I i . I 11,1 , I Ir: - - -! Ii - ~

----~~-~----~,-~- - : ~ ...

. ,I I, i

"A.1~.,*r-....~~t .• / G 'I": "'0' =! ~ 'e,; :fCo<)l i--Ol j"I) "( . . lW'!"I ~l ~~ la:Y.A.J;'\ ",(-: ~)~I

~

~ :01> I•.• /1... 41\ ):CIli- ....../~.'!~'

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