nurul zawarni binti zaim
DESCRIPTION
Drainage conditions during shearing will affect the strength parameters of soil significantly. If the sample is drained and slow shearing takes place, pore pressures will not develop and the test is called a “drained test.” However, if the sample is not allowed to drain and/or shearing occurs quickly, pore pressure is developed in the specimen and the test is called an “undrained test” (see p. 95 of the Lab Manual). In soil mechanics, effective stress decreases as pore pressure increases. In the CU-bar triaxial test discussed in this report, draining did not occur during shearing, and therefore pore pressures increased and the effective stress decreased relative to the total stress. In other words, the strength parameter of the samples decreased. The fact that the drainage valve was closed during loading makes this an undrained soil experiment as opposed to drained.TRANSCRIPT
PERPUSTAKAAN UMP
U 1111 I Iffi Ill I I 11111 U II 0000072622
I hereby declare that I have read this thesis and in my
opinion this thesis is sufficient in terms of scope and .quality for the
award of the Degree of Civil Engineering.
Signature:
Name of Supervisor
Date.............
PUPU5TAKAAN 1-1 NVERSfl1 MALAYSIA PAHANG
61709ttn No. Panggan
-m
- Tarikh
210 la 29 MAR 2013
ABSTRACT
Clay can be categorized as a troubled land. Low soil strength and height of the
pressure forces applied to be among the main factors why care must be taken into
account when making plans to build something on that site. Because of this problem, a
study of land on the basic characteristics of soil and soil stress to be done. This project
contributes to the engineering analysis features that meet the requirements of the
National Lime Association as the limits of plasticity index and the percentage of land
after land sieve analysis. Many attempts have been made to study examples of suitable
land as a sample. Overall, the test results against plastic index and sieving the soil are
likely to correspond to the increase in soil strength. From the requirements required by
the National Lime Association, land in Pekan, Pahang fit to undergo the process of
improving the strength of the soil. Pekan clay more than 90% passing 0.075mm sieve
and plasticity reaches more than 10%. Based on soil plasticity chart, Pekan clay
identified as clay with medium plasticity level. Based on Eades-Grim test, the
percentage of lime obtained from the experiments is 4 percent and a maximum pH
obtained was pH 11.8. This test shows the results of obtained pH value give almost the
same value from 4 percent to 12 percent mixture of lime. Tests on the stress of clay soils
after treatment with lime showed clay in Pekan, Pahang is 116 kPa.
ABSTRAK
Tanah hat boleh dikategorikan sebagai tanah yang bermasalah. Kekuatan tanah Yang rendah dan ketinggian daya tekanan yang dikenakan menjadi antara faktor utama
mengapa ketelitian perlu diambil kira tatkala membuat perancangan untuk membina
sesuatu di atas tempat tersebut. Disebabkan masalah mi, satu kajian tanah terhadap ciri-
ciri asas tanah dan tekanan tanah perlu dilakukan. Projek mi menyumbang kepada
anahisis kejuruteraan ciri-ciri yang menepati kehendak National Lime Association seperti
had keplastikan tanah dan peratus pelepasan tanah setelahmembuat analisis pengayakan.
Banyak percubaan telah dilakukan untuk mengkaji contoh tanah yang sesuai dia ambil
sebagai sampel. Secara keseluruharmya, daripada hasil ujian terhadap had kepalastikan
dan pengayakan terdapat besar kemungkinan tanah tersebut sesuai untuk proses
peningkatan kekuatan tanah. Daripada kehendak yang diperlukan oleh National Lime
Association, tanah di Pekan, Pahang sesuai untuk menjalani proses peningkatan
kekuatan tanah. Tanah hat lebih 90% melepasi' ayakan 0.075mm dan mencapai tahap
keplastikan lebih dan 10%. Berdasarkan carta keplastikan tanah, tanah hat di Pekan
dikenalpasti sebagai tanah hat yang mempunyai tahap keplastikan sederhana.
Berdasarkan ujian Eades-Grim, peratus kapur yang diperolehi dari proses ujikaji ialah 4
peratus dan pH maksimum yang diperolehi ialah pH 11.8. Ujian mi menunjukkan hasil
apabila nilai pH yang diperolehi mencatatkan nilai yang lebih kurang sama dari 4
peratus ke 12 peratus campuran kapur. Ujian terhadap tekanan tanah menunjukkan tanah
hat Pekan, Pahang adalah 116 kPa.
VI
TABLE OF CONTENT
CHAPTER
TITLE
PAGE
TITLE PAGE
1
DECLARATION
11
DEDICATION
111
ACKNOWLEDGEMENT
iv
ABSTRACT
V
ABSTRAK
Vi
TABLE OF CONTENTS
Vii
LIST OF TABLES x
LIST OF FIGURES xi
LIST OF ABBREVIATIONS xl"
LIST OF SYMBOLS xiv
LIST OF APPENDICES xv
INTRODUCTION
1
1.1 Intro 1
1.2 Problem statement
3
1.3 Objectives 4
1.4 Limitation 4
1.4.1 Scope of work
4
1.4.2 Testing
5
2 LITERATURE REVIEW 6
2.1 Lime 6
2.2 Properties 6
2.3 Lime Modifies Clay Soils 7
2.4 Lime Fixation In Clayey Soils 8
2.5 Effect of Lime, Moisture and Compaction on 9
a Clay Soil
2.6 A Quick Test To Determine Lime 11
Requirements For Lime Stabilization
2.7 Lime Permanently Stabilizes Clay Soil 12
2.8 Lime Stabilization of Clayey Minarels 14
2.9 Field study 15
2.10 Design of Reliable Lime-Stabilized 17
Pavement Layer
2. 10.1 Mixture design 18
2.11 Compaction 21
2.12 Strength and deformation 22
2.13 Soil Stabilisation with Lime for Road 26
Construction
2.13.1 The trial programme 28
2.13.2 Result of the test 29
2.13.3 Conclusion 30
2.14 Benefits of Lime Treatment 30
2.14.1 Research Methods and Materials 31
3 METHODOLOGY 36
3.1 Lime stabilization mix design and testing 36
procedures
3.2 Methodology 37
3.3 Testing 38
3.3.1 Initial Soil Evaluation 39
3.3.1.1 Liquid Limit Determination 39
3.3.1.2 Plastic Limit 40
3.3.2 Determine optimum lime content using 42
Eades and Grim pH test.
3.3.3 Standard Proctor test 44
3.3.4Cure and Condition the Unconfined 46
Compressive test (UCT) specimens
3.3.5 Unconfined compressive strength test 48
4 ANALYSIS DATA 49
4.1 Introduction 49
4.2 Determination of suitability for Lime 50
Stabilization
4.3 Eades-Grim test 52
4.4 Optimum Moisture Content and Maximum 53
Dry Density of the Lime-treated soil
4.5 Determine the Unconfined Compressive 56
Strength test (UCS) of the Cured and
moisture condition specimen
4.6 Benefit of soil improvement 60
5 CONCLUSION 62
5.1 Conclusion 62
5.2 Comparison 63
5.3 Recommendation 64
REFERENCES 65
LIST OF TABLES
TABLE NO TABLES PAGE
Comparison of the results of compaction and 22
California bearing ratio tests carried out on
kaolinite, monmorillonte and quartz with those
obtained when these materials were treated with
optimum lime content
2 Bearing capacity of the subgrade on the 34
experimental road.
3 Atterberg Limit result 50
LIST OF FIGURES
FIGURE NO FIGURES PAGE
1 Graph of Unconfined Compressive Strength versus 10
percentage Hydrated Lime.
2 Unconfined compressive strength of 23
montmorillonite with various additions of lime.
3 Unconfined compressive strength of kaolinite and 24
quartz with various additions of lime.
4 Young's modulus of kaolinite with various 26
additions of lime
5 Graph of E-modulus of the lime stabilized subgrade 29
versus day.
6 Bearing capacity of samples, 1 hour after treatment. 32
7 Bearing capacity of samples, 3 days after treatment. 33
8 Bearing capacity of samples, 28 days after 33
treatment.
9 The Elastic Modulus changes as a function of time 35
on the experimental road.
10 Methodology 37
11 Testing 38
12 A little soil sample of Liquid Limit 40
13 The soil that been rolling on hand due to Plastic 42
Limit
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Identify each bottle with the lime content 43
Record the pH for each lab lime-treated slurry 44
sample.
Soil mixture sample in the airtight. 45
Soil in the mould of standard proctor test. 46
Capillary soaking process. 47
Soil sample ready to be test. 48
Semi-log graph for particle size analysis 51
Graph of pH versus lime content 52
Graph dry unit weight versus moisture content in 53
percent for soil only.
Graph dry unit weight versus moisture content in 54
percent for soil improvement
UCS mode failure: Splitting failure 57
Stress-strain curve 58
Mohr' circle graph 59
Comparison of Beaumont clay and Victoria clay with 61
Pekan clay.
LIST OF ABBREVATION
UCS - Unconfined compressive strength
CBR - California Bearing Ratio
ASSHTO - American Association of State Highway and Transportation Officials
ASTM - American Society for Testing and Materials
LIST OF SYMBOLS
Ca - Calcium
Ca(OH)2 - Calcium hydroxide
CaCO3 - Calcium Oxide
H - Hydrogen
kPa - Kilo pascal
O - Oxygen
- degree Celsius
°F - degree Fahrenheit
w - Water content
LIST OF APPENDIXES
NO. APPENDIX PAGE
A Atterberg Test Result Soil only 67
B Atterberg Test Result Soil +Lime 68
C Standard Proctor test Soil + Lime result 69
D Standard Proctor test Soil result 70
E Unconfined Compressive Strength test 15% water content result 71
F Unconfined Compressive Strength test 20% water content result 72
C Unconfined Compressive Strength test 25% water content result 73
H Calibration chart 74
I Sieve analysis test result 75
CHAPTER 1
INTRODUCTION
Soil is the base of any structures as building will stand firm on it. Normally, a
base must be strong, can resist failure and able to support huge load of a structure. This
is why, before any constructions work can be done, analysis and study must be applied
to the soil in order to know the condition of the soil. The soil will give problems and
difficulties to engineers as soil can present in many types, properties and strength. The
variety of the soil is the factors that cause some soil to undergo excessive settlement,
collapse, and have distinct lack of strength.
Soft clay soil can be categorized as problematic soil. The low strength and high
compressibility characteristics the soil had are the major reasons why a careful design
analysis should be taken for any structure built on it. Due to these problems, soil
investigation on the basic properties and shear strength of the soil must be carried out.
Clay is one of the three principal types of soil, the other two being sand and
loam. A certain amount of clay is a desirable constituent of soil, since it binds other
kinds of particles together and makes the whole retentive of water. Excessively clayey
soils, however, are exceedingly difficult to cultivate. [1]
Clay stiffness presents resistance to implements, impedes the growth of the
plants, and prevents free circulation of air around the roots. They are cold and sticky in
wet weather, while in dry weather they bake hard and crack. Clods form very often in
clayey soils. Clays can be improved by the addition of lime, chalk, or organic matter;
sodium nitrate, however, intensifies the injurious effects. In spite of their disadvantages,
the richness of clay soils makes them favourable to the growth of crops that have been
started in other soil.
Soil improvement is usually an alternative to the provision of a structural
solution to a practical problem, such as provision of retaining wall or buttresses,
thickening of road pavements or increasing the extent of foundations. In the case of clay
soils, chemical improvement is commonly most effective since it can be used to change
the nature of the material. Chemical means can be used tostrengthen the soil, but also to
remove its sensitivity both to water and its subsequent stress history.
Lime in the form of quicklime (calcium oxide - CaO), hydrated lime (calcium
hydroxide - Ca[OH]2), or lime slurry can be used to treat soils. Quicklime is
manufactured by chemically transforming calcium carbonate (limestone - CaCO3) into
calcium oxide. [2]
Hydrated lime is created when quicklime chemically reacts with water. It is
hydrated lime that reacts with clay particles and permanently transforms them into a
strong cementitious matrix. Most lime used for soil treatment is "high calcium" lime,
which contains no more than five percent magnesium oxide or hydroxide. On some
occasions, however, "dolomitic" lime is used.
Dolomitic lime contains 35 to 46 percent magnesium oxide or hydroxide.
Dolomitic lime can perform well in soil stabilization, although the magnesium fraction
reacts more slowly than the calcium fraction. Sometimes the term "lime" is used to
describe agricultural lime which is generally finely ground limestone, a useful soil
amendment but not chemically active enough to lead to soil stabilization. [2]
1.2 PROBLEM STATEMENT
Clay is a material with low strength and markedly affected by water but it can be
relatively strong in dry condition. If water is added to clay, it will behave as plastic or
flow like liquid. Soft clay normally has very high percentage of clay fraction. Because of
its low permeability, dissipation of excess pore pressure in soft clay is slow. This
phenomenon creates a lot of problem at construction site in Malaysia, so the
improvement of soil is needed.
Lime provides an economic and powerful means of chemical improvement, as
demonstrate by the dramatic transformation that is evident on mixing lime with heavy
clay. The traditional used of lime stabilization is in the treatment of clay subgrades to
create improved road foundations without the need for large quantities of imported
granular aggregates.
The problems at site are sometime unlike sand, silt and loam soils, clay soils
have small, densely packed particles that are difficult to penetrate. Once the soil is
penetrated with water, it holds onto it for a long period of time. In general construction
problems in this deposit are insufficient bearing capacity, excessive post
construction settlement and instability on excavation and embankment forming.
1.3 OBJECTIVES
Pekan clay soils need to do the improvement method. A research had been done
to know the suitability and the effectiveness of the improvement method. The objectives
of this study are:
a) To determine the soil strength with adding of hydrated lime to the clay
soil,
b) To check the properties of the clays before and after treatment on
plasticity index.
C) To determine the optimum lime content required in the soft soil at Pekan.
1.4 LIMITATION
1.4.1 Scope of work
Scope of works is plan based on the study requirement. Every testing need to
Provide the sample of the soft soil. The sample will be used is clay soil at Pekan,
Pahang. The lime to be used in this research is hydrated lime. By identifying the
engineering properties of soil that will be analysed, the matters need to be considering
are the colour of the soil and particle size in order to fulfil the criteria for soil
improvement.
1.4.2 Testing
The need for finding the optimum lime content, the Eades-Grim test need to be
done. In the test, we only consider hydrated lime with different percentage of content to
be mix with the clay soil. The constant pH level and the less of hydrated lime content
will be selected as the optimum lime content for the clay soil.
By using the optimum lime content, the proctor test done to know the optimum
moisture content and maximum dry density of the clay soil. The moisture content with
different percentage in 5 percent, 8 percent, 10 percent, 15 percent, 20 percent and 30
percent are to be tested by mixing with the soil and optimum lime content.
The curing process are done by wrapping the specimen in plastic wrap and seal
in air tight, moisture proof bag. Cure the specimens for 1 4days at 40°C ± 5°C. After that,
place the cure specimen on the porous plate in contact with water before testing.
CHAPTER 2
LITERITURE REVIEW
2.1 Lime
Calcium hydroxide, traditionally called slaked lime, is an inorganic
compound with the chemical formula Ca(OH)2. It is a 6olourless crystal or white powder
and is obtained when calcium oxide (called lime or quicklime) is mixed, or "slaked"
with water. It has many names including hydrated lime, builders lime, slack lime, Cal,
or pickling lime. It is of low toxicity and finds many applications, including for food.
2.2 Properties
When heated to 512 °C, the partial pressure of water in equilibrium with calcium
hydroxide reaches 101 kPa, which decomposes calcium hydroxide into calcium oxide
and water. [1]
Ca(OH)2 -p CaO + H20
A suspension of fine calcium hydroxide particles in water is called milk of lime.
The solution is called lime water and is a medium strength base that reacts
with acids and attacks many metals. Lime water turns milky in the presence of carbon
dioxide due to formation of calcium carbonate:
Ca(OH)2 + CO2 -* CaCO3 + H20
Calcium hydroxide crystallizes in the same motif as cadmium iodide. The layers
are interconnected by hydrogen bonds.
2.3 Lime Modifies Clay Soils
On many construction sites there is a need for short-term soil modification to
temporarily strengthen the working area. The benefits of modified soils include:
1. Making clay soils friable and easier to handle.
2. Providing a working-platform for subsequent construction.
3. Reducing plasticity to meet specifications.
4. Conditioning the soil for further treatment.
5. Spot treatment of spongy subsoil areas.
After initial mixing, the calcium ions (Ca++) from the lime migrate to the surface
of the clay particles and displace water and other ions. The soil becomes friable and
granular, making it easier to work and compact. At this stage the Plasticity Index of the
soil decreases dramatically, as does its tendency to swell and shrink. The process, which
is called "flocculation and agglomeration," generally occurs in a matter of hours. Small
amounts of lime, suchas 1% to 4% by mass of dry soil, can upgrade many unstable fine-
grained soils. With heavy clay soils, additional lime may be necessary for these
purposes. Modification improvements are generally temporary and will not produce
Permanent strength in clay soils. [4]
2.4 Lime fixation in clayey soils
Previous work in stabilization of clayey soils with lime has shown that small
amounts of lime considerably improve workability but contribute little to strength,
whereas larger amounts of lime also improve the strength and bearing capacities of these
soils. This suggests the possibility that lime added to soil must first satisfy an affinity of
the soil for lime, an affinity referred to as lime fixation.
In some clayey soils the addition of flyash with the lime caused an even more
significant gain in strength. The research described in this paper was undertaken to
determine whether lime fixation does occur, and if so, to determine the mechanisms
involved and the amount of lime utilized.
Samples of six natural clayey soils were mixed with varying amounts of lime (0
to 12 percent), cured two days at 100 percent humidity and 70 Fahrenheit temperature,
and subjected to Atterberg limits tests. Similar mixes were compacted at optimum
11-1 oisture content to standard proctor density and tested in unconfined compression after
7 and 28 days moist curing. Curves of lime content versus Atterberg limits and lime
content versus unconfined compressive strength indicate that when the plastic limit
increases, with small amounts of lime, the strength remains relatively constant, whereas
with larger amounts of lime the plastic limit remains constant and strength increases.
Thus, the plastic limit is indicative of the amount of lime fixation in clayey soils. Further
correlations show that the amount of fixation is proportional to the type and amount of
2-micron clay present and is independent of the adsorbed cation present. [5]
As a result of the unconfined Compressive strengths, kaolinitic and
montmorilloflitic clayey soils were found to be well stabilized with lime alone, whereas
ill jtic- chioritic clayey soils require additions of flyash to obtain significant gains in
strength.
2.5 Effect of Lime, Moisture and Compaction on a Clay Soil
In an effort to use economically material otherwise unsuitable for subgrade
construction, the state of Virginia is in many instances adding a small percentage of lime
to improve such material. This project investigates the change in engineering
characteristics of a typical clay soil when different amounts of hydrated lime were
added.
The testing program consisted mainly of studying the effect of three variables-
percent lime, moisture content, and compactive effort by fabricating California Bearing
Ratio (CBR) specimens and obtaining values of CBR, density, and swell. In addition,
Atterberg limit determinations were made on the soil containing different percentages of
]line. [61
The trends shown by this study are:
a) The plastic properties of the soil were improved appreciably by the addition of
hydrate lime.
b) Addition of hydrated lime materially increased the strength of soil as measured
by the California Bearing Ratio method.
c) Increases in compactive effort were more effective on lime-treated soil than on
untreated soil.
d) For the natural soil, the values of California Bearing Ratio as molded were
generally greater than those of California Bearing Ratio soaked for 4 days, but
with the addition of lime the situation was reversed and the California Bearing
Ratio - soaked values observed were greater than those of California Bearing
Ratio as molded.
e) Although the increase in lime content increased the California Bearing Ratio as
molded, the change was not a pronounced as for California Bearing Ratio
soaked.
The addition of hydrated lime reduced the swell percentage of the clay soil
appreciably.
g) The California Bearing Ratio test on natural soil and soil-lime mixture using
varying compactive effort and moisture content indicated that strength is a
function of both density and moisture content. [6]
2.6 A Quick Test to Determine Lime Requirements for Lime Stabilization
The use of hydrated lime, CaOH2 for modifying, upgrading, and stabilizing soils
is increasing greatly. This means highway laboratories have had their work loads
increased, and in many instances, more than doubled for a particular job. Before the
advent of the use of lime, the laboratory was finished with testing when a soil was
classified as unsuitable. Now the same soil is tested and retested to find the percentage
of lime required to bring the soil within specifications. [7]
In most cases the percentage is determined by compressive tests, Atterberg limits
tests, or both. The reaction of lime and soil can be described as a series of chemical
reactions. The results of these reactions are expressed as a change in the plasticity, swell,
shrinkage or compressive strength of the soil.
Therefore, a quick or simple test is needed to show the amount of lime required
to react chemically with a soil to bring about these physical changes to an optimum
degree. Laboratory tests, involving mineralogical, physical and chemical characteristics
of untreated and lime treated soils have proven that pH tests can be used to determine
the optimum lime requirements of a soil.
The soil-lime pH test is performed as a test to indicate, the soil-lime proportion
needed to maintain the elevated pH necessary for sustaining the 'reactions required to
stabilize a soil. The test derives from Eades and Grim. Performance tests are normally
conducted in a laboratory to verify the results of this test method.
_L /_
Eades-Grim test is a method to know the pH level of soil reacts with lime. This
method describes the determination of the actual lime content of a lime-treated soil using
the pH method. Determinations are based on comparing the pH of a lime-treated soil to
the pH of a similar untreated soil at various known percent lime content.
This test method will not provide reliable information relative to the potential
reactivity of a particular soil, nor will it provide information on the magnitude of
increased strength to be realized upon treatment of this soil with the indicated percentage
of lime. This test method can be used to estimate the percentage of lime as hydrated lime
or quicklime needed to stabilize soil.
2.7 Lime Permanently Stabilizes Clay Soils
In contrast to lime modification, lime creates long-lasting changes in soil
characteristics that provide structural benefits. Lime is used in stabilizing and
strengthening subgrades (or sub-bases) and bases below pavements. Non-pavement
applications for lime treatment include building foundations and embankment
stabilization.
Lime stabilization chemically changes most clay soils:
1. Markedly reduces shrinkage and swell characteristics of clay soils.
2. Increases unconfined compressive strength by as much as 40 times.
3. Substantially increases load-bearing values as measured by such tests as
CBR, R-value, Resilient Modulus, and the Texas Triaxial tests.
4. Develops beam strength in the stabilized layer and greatly increases the
tensile or flexural strength.