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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
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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.
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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.
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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.
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63
Naasra (1986), A Guide to stabilization in Road Work, Sydney, Australia.
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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.
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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- ....../~.'!~'
'"