fabric and strength of clays stabilized with lime …7.1 scanning electron micrograph of lime 41...

FABRIC AND STRENGTH OF CLAYS

STABILIZED WITH LIME

by

MEHDI ARABI

Thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy of the Council for National Academic Awards, London.

VOLUME II

Department of Civil Engineering and Building,

The Polytechnic of Wales, Pontypridd, Mid Glamorgan, U.K.

Collaborating Establishment:

Wimpey Laboratories Limited, Hayes, Middlesex, U.K.

October, 1987

CONTENTS - VOLUME II

LIST OF FIGURES

Page No.

CHAPTER TWO

2.1 Principal particle size scales and a chart 1 showing percent clay, silt and sand in soil, after Yong and Warkentin [3]

2.2 Crystal chemistry of silicates, after 2,3 Mitchell [5].

2.3 Diagrammatic sketch of the kaolinite structure 4 and its charge distribution, after Mitchell [5].

2.4 Diagrammatic sketch of the montmorillonite 5 structure and its charge distribution, after Mitchell [5].

2.5 Diagrammatic sketch of the structure of 6 muscovite and its charge distribution after Mitchell [5],

2.6 Diagrammatic sketch of the structure of 7 chlorite, after Grim [6].

CHAPTER THREE

3.1 Effect of addition of lime on the plastic 8 limit of soils, after Hilt and Davidson [22].

3.2 Recommended amounts of lime for stabilization 9 of subgrades and bases, after McDowell [35].

3.3 Compressive^strength of lime treated clays, 10 cured at 61 " Grim [49].cured at 60°C for 72 hours, after Eades and

3.4 Comparison of continuous and cyclic freezing 11 for silty clay soil, after Croney and Jacobs [80].

3.5 Schematic illustration of upward flow of soil 12 moisture towards ice crystal, after Gillott [4],

3.6 Relation between temperature below freezing 13 point and suction, after Croney and Jacobs [80].

3.7 Temperature distribution beneath concrete road, 14 Jan 1963 and effect on soil suction, after Croney and Jacobs [80].

CHAPTER FOUR

4.1 Schematic illustration of states of colloidal IS dispersions and settled volumes (stable dispersion, coagulation, heterocoagulation and flocculation), after Ottewill [95].

4.2 Solubility diagrams for alumina, quartz and 16 calcium hydroxide, after Ottewill [95],

4.3 Crystal structure of calcium hydroxide, after 17 Grudemo [109],

4.4 Structure of C-S-H gel, after Grudemo [109]. 18

4.5 Structure of C-S-H gel, after Taylor [131], 19

4.6 Suggested structure for C-S-H gel, after 20 Taylor and Roy [108].

4.7 Suggested C-S-H gel structure, illustrating 21 bonds between and along sheets and polymerization of silicate chains, after Ramachandran et al. [140].

4.8 Three mechanisms of expansion of tobermorite 22 gel, after Brunauer [107].

4.9 Simplified pore model for C-S-H gel, after 23 Daimon et al. [130].

4.10 TG of synthetic C-S-H (I), after James 24 and Subba Rao [148].

4.11 TG curves for various C-S-H specimens, after 25 El-Hemaly et al. [128].

4.12 The loss of water from hydrated calcium 26 aluminates on ignition, after Lea [163].

CHAPTER FIVE

5.1 Particle-size distribution curve of the 27 Red Marl.

CHAPTER SIX

6.1 Relation between dry density and moisture 28 content for Red-Marl without lime additions.

6.2 Schematic representation of the self-level cap 29 used for measurement of the unconfined compressive strength.

6.3 Mercury penetration under pressure, after 30 Carlo Erba, Sci. Inst-[175).

6.4 Typical mercury porosimetric graph for a 31 soil-6 wt% lime specimen, cured for 24 weeks in a moist environment at 75 C.

6.5 Schematic representation of the apparatus used 32 for measurement of the permeability of the cured soil-lime specimens.

6.6 Relationship between dynamic viscosity of 33 water and temperature, after Head [177],

6.7 Schematic representation of the apparatus used 34 for the investigation of frost heave on the cured soil-lime specimens.

6.8 Schematic representation of the specimen 35 position in the freezing cabinet.

6.9 Plot of water absorption against time for 36 soil-lime cylinders of various compositions cured for 12 weeks at 50°C.

6.10 Geometrical conditions for X-ray diffraction 37 according to Bragg's Law, after Mitchell [5].

6.11 Interaction of electron beam with crystalline 38 sample and a schematic electron distribution in a bulk sample and a thin foil, after Lorimer and Cliff [180].

6.12 Schematic representation of the path of the 39 electron rays in a two stage electron microscope for bright field, dark field and diffraction image, after Beutelspacher and Van der Marel [181].

6.13 EDAX analysis of tanzanite and okenite using 40 TEM.

CHAPTER SEVEN

7.1 Scanning electron micrograph of lime 41 [Ca(OH) 2 ].

7.2 Thermogravimetric results for Ca(OH) 2 and 42 CaCO3 .

7.3 Thermogravimetric results for Red-Marl. 43

7.4 Dehydration curves for some clay micas and 44 related minerals, after Mackenzie [182].

7.5 Scanning electron micrographs of the Red-Marl. 45

7.6 EDAX results from TEM studies of soil particles 46 showing illite and chlorite compositions.

in

7.7 EDAX results from TEM studies of soil particles 47 showing albite and glauconite compositions.

7.8 Scanning electron micrograph of kaolinite. 48

7.9 TEM micrograph, electron diffraction pattern 49 and EDAX analysis of untreated kaolinite.

7.10 Thermogravimetric result for kaolinite. 50

7.11 Scanning electron micrograph of montmorillonite. 51

7.12 Thermogravimetric result for montmorillonite. 52

7.13 Scanning electron micrographs of illite. 53

7.14 Thermogravimetric result for illite. 54

7.15 Relation between liquid limit and lime content. 55

7.16 Relation between plastic limit and lime content. 56

7.17 Relation between plasticity index and lime 57 content.

7.18 Plasticity chart showing changes in plasticity 58 of lime treated Red-Marl.

7.19 Plasticity chart indicating the influence of 59 lime content, curing period and curing temperature on plasticity.

7.20 Plot of unconfined compressive strength against 60 curing time for soil-lime cylinders of various compositions cured in a moist environment at 25 C.



7.23 Variation in compressive strength with lime 63 content for 24 week moist-cured soil-lime cylinders at different temperatures.

7.24 Plot of unconfined compressive strength against 64 lime content for soil-lime cylinders cured for 12 weeks in a moist environment at 50 C.

7.25 Relationship between pH values and lime content 65 for slurries of Red-Marl after 1 hour at room temperature.

IV

7.26 Plot of unconfined compressive strength against 66 curing time for soil-lime cylinders of various compositions cured in an unsealed environment at room temperature (~20 C).

7.27 Plot of unconfined compressive strength against 67 curing time for soil-lime cylinders of various compositions cured in an unsealed environment at 25°C.

7.28 Plot of unconfined compressive strength against 68 curing time for soil-lime cylinders of various compositions cured in an unsealed environment at 50°C.

7.29 Plot of unconfined compressive strength against 69 curing time for soil-lime cylinders of various compositions cured in an unsealed environemnt at 75°C.

7.30 Variation in moisture content with curing time 70 for the specimens cured at different temperatures in unsealed environments.

7.31 Plot of unconfined compressive strength against 71 moisture content for untreated Red-Marl cylinders.

7.32 Plot of unconfined compressive strength against 72 curing time for soil-lime cylinders of various compositions cured in a nitrogen environment at room temperature (~20°C).

7.33 Plot of unconfined compressive strength against 73 curing time for soil-lime cylinders of various compositions cured in a carbon dioxide environment at room temperature (~20 C).

7.34 Variation in moisture content with curing period 74 for soil-14 wt% lime specimens cured in nitrogen and carbon dioxide environments.

7.35 Variation in weight during curing period for 75 specimens of various compositions cured in a carbon dioxide environment.

7.36 Effect of delay between mixing and compacting on 76 the unconfined compressive strength of soil-6 wt% lime cylinders cured for 12 weeks in a moist environment at 25, 50 and 75 C.

7.37 Effect of soil particle size on the unconfined 77 compressive strength for soil-6 wt% lime cylinders cured for 12 weeks in a moist environment at 50 C.

7.38 Plot of unconfined compressive strength against 78 curing time for soil-lime-1 wt% sodium chloride cylinders cured in a moist environment at 25 C.

7.39 Plot of unconfined compressive strength against 79 curing time for soil-lime-1 wt% sodium chloride cylinders cured in a moist environment at 50°C.

7.40 Plot of unconfined compressive strength against 80 curing time for soil-lime-1 wt% sodium chloride cylinders cured in a moist environment at 75°C.

7.41 Cumulative pore volume against pore radius for 81 soil-10 wt% lime specimens cured at 25°C for 1 and 24 weeks.




7.45 Cumulative pore volume against pore radius for 85 soil-10 wt% lime specimens cured for 24 weeks at 25 and 75°C.

7.46 Cumulative pore volume against pore radius for 86 soil-2 wt% lime, soil-6 wt% lime and soil-10 wt% lime specimens cured for 24 weeks at 75°C.

7.47 Total pore volume against lime content for 87 specimens cured at 75 C for 1 and 24 weeks.

7.48 Permeability against lime content for specimens 88 cured at 25 C for 1 and 24 weeks.



7.51 Permeability against curing temperature for 91 specimens of various compositions cured for 24 weeks.

VI

7.52 Permeability against the percentage porosity 92 contributed by pores of radius greater than 40nm.

7.53 Frost heave against curing time for soil-lime 93 cylinders of various compositions cured at 25°C.



7.56 Frost heave against lime content for soil-lime 96 cylinders cured for 1 and 24 weeks at 25°C.

7.57 Frost heave against lime content for soil-lime 97 cylinders cured for 1 and 12 weeks at 50 C.

7.58 Photographs illustrating the frost heave and 98 formation of ice lenses in soil-lime cylinders of various compositions cured at different temperatures.

7.59 Thermogravimetric results for soil and cured 99 soil-lime samples, cured for 24 weeks at 50°C.

7.60 Plot of the wt% "consumed lime" against the wt% 100 loss of "gel water" in the temperature region 100-250°C.

7.61 Plot of unconfined compressive strength against 101 wt% "consumed lime" for soil-lime specimens cured at 50°C for various times.

7.62 Scanning electron micrograph of the fracture 102 surface of a 24 week (50°C) cured soil-14 wt% lime sample.

7.63 Part of the X-ray diffractometer of soil-10 wt% 103 lime sample cured for 1.5 years at 75 C.

7.64 Scanning electron micrographs of the fracture 104 surface of a 1 day (75°C) cured soil-10 wt% lime sample.

7.65 Scanning electron micrographs of the fracture 105 surface of a 3 weeks (75°C) cured soil-10 wt% lime sample.

7.66 Scanning electron micrographs of the fracture 106 surface of a 6 weeks (75°C) cured soil-10 wt% lime sample.

7.67 Scanning electron micrographs of the fracture 107 surface of a 6 week (75 C) cured soil-10 wt% lime sample and a 4 week cured Portland cement.

vii

7.68 SEN and EDAX results of the platelet particles 108 formed in a soil-10 wt% lime sample cured for 6 weeks at 75°C.

7.69 Scanning electron micrographs of the fracture 109 surface of 12 week (75 C) cured soil-10 wt% lime sample.

7.70 Scanning electron micrographs of the fracture 110 surface of 6 month (75 C) cured soil-10 wt% lime sample

7.71 Scanning electron micrographs of the fracture 111 surface of 1 year (75°C) cured soil-10 wt% lime sample.

7.72 Scanning electron micrographs of the fracture 112 surface of 18 month (75 C) cured soil-10 wt% lime sample.

7.73 Scanning electron micrographs of the fracture 113 surface of 2 year (75°C) cured soil-10 wt% lime sample.

7.74 Typical transmission electron micrographs 114 showing gel morphology after one year at 75 C for a soil-10 wt% lime sample.

7.75 Transmission electron micrograph and EDAX 115 analysis of gel formed in soil-10 wt% lime composite cured in a moist environment at 75 C for one year.

7.76 Transmission electron micrograph of typical 116 gel particle together with its electron diffraction pattern.

7.77 TEM micrograph and EDAX analysis of gel formed 117 in a soil-10 wt% lime composite cured in a moist environment at 75 C for 1 year.

7.78 TEM micrograph and EDAX analysis of gel formed 118 in soil-10 wt% lime comgosite cured in a moist environment at 75 C for 1 year.

7.79 TEM micrograph and EDAX analysis of gel formed 119 in a soil-10 wt% lime composite cured in a moist environment at 75 C for six weeks.

7.80 TEM micrograph and EDAX analyses of gel formed 120 on the borders of a quartz particle inQa soil-10 wt% lime composite cured at 75 C for 1 year.

viii

7.81 Scanning electron micrographs of the fracture 121 surface of a 12 week (75°C) cured refined Marl-20 wt% lime sample.

7.82 DTG traces for refined Marl-20 wt% lime samples 122 cured for 1 day to 24 weeks at 75 C.

7.83 TG traces for refined Marl-20 wt% lime samples 123 cured for 1 day to 24 weeks at 75°C.

7.84 Plot of reacted lime against curing time for 124 refined Marl-20 wt% lime samples cured at 75°C.

7.85 TEM micrograph, electron diffraction pattern 125 and EDAX analysis of gel formed in a refined Marl-20 wt% lime composite cured for 6 weeks at 75°C.

7.86 TEM micrograph, electron diffraction pattern 126 and EDAX analysis of gel formed in a refined Marl-20 wt% lime composite cured for 24 weeks at 75°C.

7.87 Part of the X-ray diffractometer of 127 montmorillonite-20 wt% lime sample cured for 12 weeks at 75 C.

7.88 Thermogravimetric results for 128 montmorillonite-20 wt% lime sample, cured for 12 weeks at 75°C.

7.89 TEM micrograph, electron diffraction pattern 129 and EDAX analysis of gel formed in a montmorillonite-20 wt% lime composite cured for 12 weeks at 75°C.

7.90 TEM micrograph and EDAX analysis of gel formed 130 in a montmorillonite-20 wt% lime composite cured for 12 weeks at 75 C.

7.91 Parts of the X-ray diffractometer of 131 kaolinite-20 wt% lime sample, cured for 12 weeks at 75°C.

7.92 Thermogravimetric results for untreated 132 kaolinite and kaolinite-20 wt% lime sample cured for 12 weeks at 75 C.

7.93 TEM micrograph, electron diffraction pattern 133 and EDAX analysis of gel formed in a kaolinite-20 wt% lime composite cured for 12 weeks at 75°C.

7.94 TEM micrograph and EDAX analysis of gel formed 134 in a kaolinite-20 wt% lime composite cured for 12 weeks at 75°C.

ix

7.95 TEN micrograph and EDAX analysis of gel formed 135 in a kaolinite-20 wt% lime composite cured for 12 weeks at 75°C.

7.96 Part of the X-ray diffractometer of 136 illite-20 wt% lime sample cured at 75°C for 12 weeks.

7.97 Thermogravimetric results for illite-20 wt% 137 lime sample cured at 75°C for 12 weeks.

7.98 Scanning electron micrographs of the fracture 138 surface of illite-20 wt% lime sample cured for 12 weeks at 75°C.

7.99 Typical TEM-EDAX analysis of gel formed in 139 illitep;20 wt% lime sample cured for 12 weeks at 75OC"

CHAPTER EIGHT

8.1 Crystal structure of Ca(OH) 2 , 140 after Taylor [131]

8.2 Representation of an idealized Si^O^ sheet 141 and the idealized dioctahedral sheet.

8.3 SEM micrographs of a 24 week cured soil-10 wt% 142 lime sample at 75°C showing exfoliation and breakdown of the clay layers.

8.4 SEM-EDAX analysis at point "X" in 143 Figure 8.3(a).

8.5 Representation of illite structure. 144

8.6 Phase development in the system CaO-Si02-H20 145 showing the course of cement-pozzolana-water reactions, after Glasser and Marr [192].

CHAPTER TWO

i—mil mi i i mini iiiiniii iiniiiii iiiniin i i numOOOCI 0001 001 01 X) 100

OorrwKr (1090'i'tmc tea*!, m"

Grovel

US Dwortmem rf Jkpiullurt

005 01 025 05 I 2

ftmODO? OOO6 002 005 01 02 Oi I 2 i 6 JO

I Sona —— T,. u 5 Publ.c Hoods I Fun I CCQIM I 6"'t "T *dininiilrot«n

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(a)

inv c( Tc-. B B ,,, isri s , nn<)0 ,,_

100A°

60 40 Per Cent Sond

100

Figure 2.1

(a) Principal particle size scales

(b) Chart showing percent clay, silt and sand in soil,

after Yong and Warkentin [3]

Combinationof

TetrahedraDiagrammatic Representation ol Structure

Si-OGroup and

Negative Charge

Oxygen to SiliconHdtIO

E xdmple

Island Independent

(Si0 4 )«- 4 : 1 Ohvmes (Mg. Fe) 2 Si0 4

Double (S, 2 0,l 6 - 7 2 Amermanlte

Rings

><ISi 6 0, 8 >'-

3 1

Beniroite 8aT,Si,O,

Beryl 3e.,AI 2 S. 6 0, B

Chains 3 1 Pyroxenes

Bands11 4 Amphibotes

Figure 2.2

Crystal chemistry of silicates, after Mitchell [5!

Combinationol

TetrahedraDiagrammatic Representation of Structure

Si-0Group and

Negative Charge

Oxygen toSilicon Ratio

Example

Sheets

A A AX V V ___A /

V v v

5 2

Frameworks 2 1Quartz SiO,

Also feldspars, 'or example, orthoclase. KAISi 3 08

Figure 2.2

(continued)

(a)

6 (OH)

tetrahedron

Net Charge +28-28

(b)

Figure 2.3

(a) Diagrammatic sketch of the kaolinite structure

(b) Charge distribution in kaolinite, after Mitchell [5]

Exchangeable Cations

O*vg«ns y Hydroxyls Aluminum. Iron, Magnesium

O and 0 Silicon, Occasionally Aluminum \ O j

Net Charge +44 - 44 = 0

Figure 2.4

(a) Diagrammatic sketch of the montmorillonite structure

(b) Charge distribution in pyrophyllite

(type structure for montmorillonite, after Mitchell [5])

f } Oxygent. toy Hydroxyls, ^B Aluminum, ( ) Potassium

O and Silicons (One Fourth Replaced by Aluminums) ( 3 )

Net Charge + 44-44 = 0 OP

Figure 2.5

(a) Diagrammatic sketch of the structure of muscovite

(b) Charge distribution in muscovite, after Mitchell [5]

Figure 2.6

Diagrammatic sketch of the structure of chlorite,

after Grim [6]

CHAPTER THREE

PL

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r | j 3 \ i 1 } : i i 3 f : c t 1 . i i * \ 'r • 5 i i • L I | I 1 I : _ * i £ * J i/ i i 3 " 1 g f \ t 1 « i * * i * ** i l i i I I

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—— O WHITE MMNM IKMITIKMILLOftfTt—— • KCKOCCM «IO«T«O«ILLOIIITt——d •TOKIII* tiOWTMOKILUWITI——-A nTHIMI ILLITC

•KUKOITf

2 4 6 8 K> 12 LIME ADDED

Figure 3.3

Compressive strength of lime treated clays, cured

at 60°C for 72 hours, after Eades and Grim [49]

10

Soil

Brickearth (1) Harmondswofth

Index tests

LL[p*r wot )

25

PLtp«r c*nt )

17

PIIptrant!

8

Particle siiePassing

200 sieve(per c»nl )

79

Clay contentIptr cent }

2t

Sample compact «mDry

density

111 116

Moisture content(per ctnt 1

13 13

15

o mX

05

^ 111tb/ft3

Measured heavecontinuous freezi

116lb/ft 3 _

Heave deduced from cyclic freezing

_L50 100 150 200

Hours of freezing

(a) CYCLIC AND CONTINUOUS FREEZING

250 300

15

10 -

600

(b) HEAVE FOR CYCLIC FREEZING

Figure 3.4

Comparison of continuous and cyclic freezing

for silty clay soil, after Croney and Jacobs [80]

11

Soil

Ice cryslil

MoUlurc lilm (Hulll

\ *diorptint lorcts

r

\Joil pirlicit

Figure 3.5

Schematic illustration of upward flow of soil

tooisture towards ice crystal, after Gillott [4]

12

oI£

0

tt

3 2g

3 35 4 45Suction ot unfrozen moisture (pF)

Figure 3.6

Relation between temperature below freezing point

and suction, after Croney and Jacobs [80]

13

Temperature (degC)

-2 0

25

_ 10c

a.«* O 15

20

25

Sueti'on ( P F)

2 3

CONCRETE

Equilibriumsuction(unfrozen)

Suction for"temperature distribution of (a)

(a) TEMPERATURE DISTRIBUTION (M SOIL SUCTION

Figure 3.7

Temperature distribution beneath concrete road, Jan 1963, and

effect on soil suction, after Croney and Jacobs [80]

14

CHAPTER FOUR

o.o

(a) fc) Id}

Figure 4.1

States of colloidal dispersions (upper sketch)

and settled volumes (lower sketch):

(a) stable dispersion (b) coagulation,

(c) heterocoagulation, (d) flocculation,

after Ottewill [95]

15

-104 6 8 10

pH13

i E•o•o

S -2

c c u

Ca(OH)' \

10 12

CalOH),

14

Figure 4.2

Solubility diagrams for alumina, quartz and

calcium hydroxide, after Ottewill [95]

16

Layer lattice element with Ca ions

(cubes) in octahedral positions

between OH ions, situated 0.147nm

above and below the Ca plane. More

exact cell size 0.3593nm. Next

layer stacked directly on top, at a

distance of 0.4909nm.

CH structure

Figure 4.3

Crystal Structure of calcium hydroxide,

after Grudemo [109]

17

C-S-H gel structure

(a) C-S-H gel layer, based on the CH cell Cubes - Ca. tetrahcdra - Si, circles - 0 or OH

(b) Mosaic of CH-type cells in C-S-H layer. C/S • 1.68

Figure 4.4

Structure of C-S-H gel, after Grudemo [109]

18

A chain of CaO. octahedra sharing O-O edges with each other, and individual oxygen atoms with {a) S>>:Oi groups: (b) Si»Oi» groups and (c) longer Si-O chains

Figure 4.5

Structure of C-S-H gel, after Taylor [131]

19

50 n m

^Ca-0 sheets with attached anions including Si 207

• Typical spaces containing Ca H20 and anions including

compact polysilicate anions.

Figure 4.6

Suggested structure for C-S-H, after Taylor and Roy [108]

20

H H°'M M ~° CO

X M M /• Co** M0-Co_

H H M

POSSIBLE BONDS

BRIDGING BETWEEN SHEETS

5.

6' riI 'TO.U.-J

V.M

ALONG SHEETS

1.

Co

H H'o

Figure 4.7

Suggested C-S-H gel structure, illustrating bonds between

and along sheets and polymerization of silicate chains,

after Ramachandran et al. [140]

21

©

Figure 4.8

Three mechanisms of expansion of tobermorite gel,

after Brunauer [107]

22

OtfpwtcM

x : Intracrystallite pore,

o : Intercrystallite pore

• : Mono layer water

Figure 4.9

Simplified pore model for C-S-H gel,

after Daimon et al. [130]

23

WE

IGH

T

LO

SS

(W%

)

o> oM

O

nf o

•^

M)

C-i

CO

(0 00

<-r H-

O CO re

n (D

H m £ n

m a c

a m

20

10O 2OO 3OO 4OO 5OO «OO 70O 1OO 20O 3OO 4OO SCO 6OO 70OTEMPERATURE *C TEMPERATURE »C

Figure 4.11

TG curves for various C-S-H specimens,

after El-Hemaly et al. [128]

25

200 400 TLMPC.KATUKE Of ICN/JVON.'C

Figure 4.12

The loss of water from hydrated calcium

aluminates on ignition, after Lea [163]

26

CHAPTER FIVE

«m

s s

v> n

c«l U

O ®S I-IW

90

80

70

6O

50

40

30

20

10

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!

1

001 C

i

-M •"" — —

—

**•'•* t

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--— 9O

•--60

- —70

•-60

• -50

• -40

^}P

,'-20

— to

f'

yy

i^

/

OOl

i•— \-

i>T~

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j111••— 1-

••— h-

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i

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.r

x >

Ctl

f p —-f-90

- 1

- --70

- --60

... 50

- --40

- +30

- --20

- -i ,0. .1 __ .

I.OParticle size (mm)

CLAY FINE (MEDIUM [COARSESILT

FINE j MEDIUM COARSESAND

Figure 5.1

Particle-size distribution curve of the Red Marl

27

CHAPTER SIX

MOISTURE CONTENT

Figure 6.1

Relation between dry density and moisture

content for Red Marl without lime additions

28

LOADING

^^^^^^n

SPECIMEN

Figure 6.2

Schematic representation of the self-level cap used

for measurement of the unconfined compressive strength

29

V

ri I

P' <

u> rj 3

C p» <

V rj

^ rj

' pi

Figure 6.3

Mercury penetration under pressure,

after Carlo Erba, Sci. Inst. [175]

30

\XV^A\\\NSSA\\X\\X\V^\ \\ \\ \ \ V v^ ^-^

Figure 6.4

Typical mercury porosimetric graph for a soil-6 wt% lime

specimen cured for 24 weeks in a moist environment at 75 C

BURETTE

AIR VALVE

RUBBER "O"RING

WATER

TO CONSTANT ,, HEAD

I U 148 I i 8 I s S

LOWER CAP

UPPER CAP TERRAM

-RUBBER MEMBRANE

SPECIMEN

Figure 6.5

Schematic representation of the apparatus used for measurement

of the permeability of the cured soil-lime specimens

32

V5

ratio

VO

0-5

XXX"

X

1O 2Otemperature T °C

30 4O

Figure 6.6

Relationship between dynamic viscosity

of water and temperature, after Head [177]

33

GLASS WOOL

SPECIMEN

SPECIMEN HOLDER

POLYSTYRENE

COPPER TRAYWATER BATH

rr -~

nitit njiijli---

©©

-_ — -

©©_ _ __ —

©©

__ _ __ — _-

-3 -----

.-3 — - —

Figure 6.7

Schematic representation of the apparatus used for the investigations

of frost action on the cured soil-lime specimens

34

GLASS WOOL

SPECIMEN HOLDER

~ " ." ~ WATER BATH

Figure 6.8

Schematic representation of the specimen

position in the freezing cabinet

35

10 15 20

HOURS

30

Figure 6.9

Plot of water absorption against time for soil-lime cylinders

of various compositions cured for 12 weeks at 50°C

36

Incident Ray Diffracted RaY

Atomic Planes

Figure 6.10

Geometrical conditions for X-ray diffraction

according to Bragg's law, after Mitchell [5]

37

(a)

(b)

Figure 6.11

(a) Interaction of electron beam with crystalline sample

(b) Schematic electron distribution in a bulk sample and

a thin foil, after Lorimer and Cliff [180]

38

BDIM CT ION ClCCIHO" liri (Y TILTINC ILIUM III At ION STSTCM

_ _ Controst aperture _ _

_ _ Intermediate image

_ _ Projector lens _ _

Specimen _ _ _

Objective lens __

Selected oreo aperture _ __^

Diffraction lens - -

Intermediate diagram

Projector lens _ _

Fluorescent screen Photographic plate

Bright field Dork field

Final diagram

_____1_____

Diffraction pattern

Figure 6.12

Schematic representation on the path of the electron rays

in a two stage electron microscope for bright field (A)

dark field (B) and diffraction image (C),

after Beutelspacher and Van der Marel [181]

39

Tanzanite

Ca Al Si1.88 2.93 3.19

O kenite

Ca Si2.96 6.02

Figure 6.13

EDAX analysis of tanzanite and okenite using TEM

(a) tanzanite (b) okenite

40

CHAPTER SEVEN

Figure 7.1

Scanning electron micrograph of lime [Ca(OH)-1x2000

41

toto O

0

10

20

30 Ca(OH),

DTG

TG

(a)

01

O

0

10

20

30

40 CaCO,

DTG

TG

2OO 400 60O

TEMPERATURE

800 1000 C

(b)

Figure 7.2

Thermogravimetric results for

(a) Ca(OH) 2 and (b) CaC03

42

0

2VJ

O 4_jI- 6

— 8 iu^ 10

12

TG

200 400 600 800 1000 C

TEMPERATURE

Figure 7.3

Thermogravimetric results for Red-Marl

43

200 400 600 800 Temperature °C

1000

Figure 7.4

Dehydration curves for some clay micas and related minerals A-talc, B-muscovite, C-sericite,D-pyrophyllite, E-muscovite F-glauconite, G-fine-ground muscovite, H-illite, l-illite, Fithian,Illinois, U.S.A., j-illite, South Wales, K-muscovite, Goshen Massachusetts, U.S.A., after Mackenzie 1182]

44

(a)

Figure 7.5

Scanning electron micrographs of the Red-Marl

(a) X2000, (b) X5000

45

Figure 7.6

EDAX results from TEM studies of soil particles

showing illite and chlorite compositions

46

Illite

K Ca (Al Fe ) (Al Si )0.6 0.1 2 1.76 0.17' V 0.63 3.37

Chlorite

K Ca (Al Fe M9 J(AI Si )0.24 0.14 2.2 !.57 1.88 0.69 3.31

Illite

K Ca (Al Fe ) (Al Si )0.71 0.27 1.79 0.1, 0.98 3.02

Chlorite

(Al M9 Fe ) (Al Si )2.63 2.48 0.89 7 0.02 3.9 8

Albite

Na Al Si0,75 1.16 2.94

a

Glauconite

rMAS KC 9 I i a

Figure 7.7

EDAX results from TEM studies of soil particles

showing albite and glauconite compositions

(a) albite (b) glauconite

47

Figure 7.8

Scanning electron micrograph of kaolinite XlOOOO

48

0.15 AI m

I" 2 I" 4^0.98 Si 1.00

(b)

(c)

Figure 7.9

(a) TEM micrograph of untreated kaolinite

(b) electron diffraction pattern

(c) EDAX analysis

49

(0

O

8

12

16

TG

200 400 600

TEMPERATURE

800 1000 C

Figure 7.10

Thermogravimetric result for kaolinite

50

Figure 7.11

Scanning electron micrograph of

montmorillonite X5000

51

montmorjllomt*

CO COo

0

4

8

I 12ui£ 16

20

200 400 600

TEMPERATURE

800 1000 C

Figure 7.12

Thermogravimetric result for montmorillonite

52

(a)

(b)

Figure 7.13

Scanning electron micrographs of illite

(a) X2000, (b) X5000

53

* 4COCOO 8

X 12 O

I «

20

TO

200 400 600

TEMPERATURE

800 1000 C

Figure 7.14

Thermogravimetric result for illite

54

44

42

40

38

+• TESTED IMMEDIATELY A 1WEEK CUBED AT 1(*CO « WEEKS CURED AT tf*C

©14 WEEKS CUBED AT*S*C

V 1 WEEK CUNCD AT»0*C

36

34

32

30

A

O ©

A

or

©

©

6 10

LIME CONTENT^

14

Figure 7.15

Relation between liquid limit and lime content

55

O

32

30

28

26

24

-f- TESTED IMMEDIATELY

A 1WEEK CURED AT J»°C

O * WEEKS CURED AT»B*C

® 14WEEKS CUKEO AT IRC

^ 1 WEEK CUMED AT SO*CAT

-r-O®

TO

22

20

UNTREATED SOIL

6 10

LIME CONTENT^

14

Figure 7.16

Relation between plastic limit and lime content

56

LU0

>-H-

5

16

14

12

10

8

6

) UNTREATED SOIL

A

O

o®T

+ TESTED IMMEDIATELY

A 1WEEK CURED AT 16 C

O 4WEEKS CURED AT2S°C

© 24WEEKS CURED AT I5°C

W 1 WEEK CURED AT BO°C

AO AD

6 10

LIME CONTENT

14

Figure 7.17

Relation between plasticity index and lime content

57

tn

oo

x Ul o o

15-

-f-

TES

TED

IM

ME

DIA

TE

LY

A

tWE

EK

C

UR

ED

A

T »»

C

O

4WE

EK

S

CU

RE

D

AT J

S°C

©

24W

EE

KS

C

UR

ED

A

T 1S

C

1 W

EE

K

CU

RE

D

AT

*0°C

10

2025

UN

TR

EA

TE

D

SO

IL /

A''

30

35

LIQ

UID

L

IMIT

%

+

*

40

Figu

re 7

.18

Plas

tici

ty c

hart s

howing c

hanges i

n pl

asti

city

of

lime

tre

ated

Red

-Mar

l

20

O

10a.

L:LIME CONTENT

C:CURING PERIOD

TlCURING TEMPERATURE

20

UNTREATED SOIL

30 40

LIQUID LIMIT %

50

Figure 7.19

Plasticity chart indicating the influence of lime content,

curing period and curing temperature on plasticity

59

"E

E

IXI- ozUltr

UJ

CO(/) 111 ccQ.2 O O

14% LIME

8 12

AGE-WEEKS

24

Figure 7.20

Plot of unconfined compressive strength against curing time

for soil-lime cylinders of various compositions cured in a

moist environment at 25°C

60

1 2 3 8 12

AGE-WEEKS

Figure 7.21



moist environment at 50 C

61

1 2 8 12

AGE-WEEKS

24

Figure 7.22




62

216UJcc

12

111

UJcca 2 O O

10% LIME

14

Figure 7.23

Variation in compressive strength with lime content for 24 week

moist-cured soil-lime cylinders at different temperatures

63

"EE

IX h- OzUJoc

UJ

UJccCL2 O O

12

8

0 2 6 10 20 30 40

LIME CONTENT^

50

Figure 7.24

Plot of unconfirmed compressive strength against lime

content for soil-lime cylinders cured for 12 weeks in

a moist environment at 50°C

64

12.30 -

1225-

1220 -

12.15

12.10567

LIME CONTENT %

Figure 7.25

Relationship between pH values and lime content for

slurries of Red-Marl after 1 hour at room temperature

65

EEXzI

oUJcc

UJ

UJcc0.2 Oo

1 2 8 12

AGE-WEEKS

14% LIME

24

Figure 7.26


for soil-lime cylinders of various compositions cured in an

unsealed environment at room temperature (~20°C)

66

E E

oUl CCH-

UJ CC.Q.2 O U

O 1 2 8 12

AGE- WEEKS

24

Figure 7.27



unsealed environment at 25°C

67

VE STRENGTH-N/mm

COMPRESSI

7

6

5

4

3

2

ill • I

14%LIME

. I 10%

If- 6%

IT. . " 2%

L... :O 1 2 8 12 24

AGE-WEEKS

Figure 7.28



unsealed environment at 50 C

68

COMPRESSIVE STRENGTH-N/mmN> A 0> 00

14%LIME' I O/ •L . . 10%fc: • • «.II

m • • m • i

0124 8 12

AGE-WEEKS

24

Figure 7.29



unsealed environment at 75 C

69

ROOM TEMR (~20C)

0 1 2 8 12

AGE-WEEKS

o 25C

50*C

24

Figure 7.30

Variation in moisture content with curing time for the

specimens cured at different temperatures in unsealed

envi ronments

70

LU CC

LU

UJ CC Q.SOo

8 10 12 14

MOISTURE CONTENTS

Figure 7.31

Plot of unconfined conpressive strength against

moisture content for untreated Red-Marl cylinders

71

'6E

oUJcc

Ul>

CO</>UJcc0.2 O O

AGE-WEEKS

Figure 7.32



nitrogen environment at room temperature (~20°C)

EE

OzLJ QC

LU

tuDC Q.2 O O

0 1 2 8 12

AGE-WEEKS

24

Figure 7.33

Plot of unconfined conqpressive strength against curing time


carbon dioxide environment at room temperature (~20°C)

73

12

10

8

UJI- z o oUJ DC

COO 4

\

0 1 2 4

14 X LIME

NITROGEN

CARBON DIOXIDE

8 12

AGE-WEEKS

24

Figure 7.34

Variation in moisture content with curing period for soil-14 wt%

lime specimens cured in nitrogen and carbon dioxide environments

74

WEIGHT INCREASE(Qr) _ -A -k N O 01 O Cfl C• 14%LIME

[ , 'I ' « 'VV 2%Df^ —— i ——————————— • —————— 1 ————————— ,rt t ———— • ——— •124 12 24

DEGREE OF CARBONATION

97 \

«1 %

eo %

AGE-WEEKS

Figure 7.35

Variation in weight during curing period for specimens of

various compositions cured in a carbon dioxide environment

75

12

E 10

OzLU QC H CO

Ul>CO CO HIocQ.2 O O

8*

\

75°C

25°C

14

COMPACTION DELAY (DAYS)

28

Figure 7.36

Effect of delay between mixing and compacting on the unconfined

compressive strength of soil - 6 wt% lime cylinders cured for

12 weeks in a moist environment at 25, 50 and 75°C

76

12

I 10

Z UJcc

UJ

UJDC CL

8

O 2

63 150

PARTICLE SIZE

425 600(MICRON)

Figure 7.37

Effect of soil particle size on the unconfined

compressive strength for soil-6 wt% lime cylinders

cured for 12 weeks in a moist environment at 50 C

77

"E

II

OzUJcc

UJ>CO CO UJccO.

10 % LIME

8 12

AGE-WEEKS

24

Figure 7.38


for soil-lime - 1 wt% sodium chloride cylinders cured in a


78

EEZ IX »- O Z UJ<r

u>

UJcc o.2 O O

16

12

8

T ? r

10 % LIME

0 1 2 3 8 12

AGE-WEEKS

24

Figure 7.39


for soil-lime - 1 wt% sodium chloride cylinders cured in a


79

AGE-WEEKS

Figure 7.40

Plot of unconfirmed compressive strength against curing time

for soil-lime-1 wt% sodium chloride cylinders cured in a


80

O >

100 90 80 70 60 50

cc

O

Q.

40 30 20 10 0

B

10%

LIM

E

1 W

EE

K

CU

RED

AT

25°

C

J 10

% L

IME

I24

WE

EK

S

CU

RE

D

AT

25~C

i i

i i

11i

i i

i i

i r

4 6

8 10

14

8 8

10*

2 4

68

10

s"

2 4

6 8

10

* 2

4 8

8 10*

PORE

R

AD

IUS

nmFigure 7

.41

Cumulative p

ore

volume a

gainst p

ore

radius f

or s

oil

- 10 w

t% l

ime

specimens

cured

at 2

5°C

for

1 and

24 w

eeks

PORE VOLUME %

CO "8o

w

1-1 a~j • £*to

Q» rr

g * (ft »•«a <T>i-h <O O n h--^ i <ji (&0̂,s

H, «S 5'

01

NJ

at

"8i-i ID

0) CL (--

cot-h O

COoH-

Ito

%<M>

O 30m3J>Q

CO

33

PORE VOLUME %

10%

LIM

E

' 1

WE

EK

C

UR

ED

A

T 75

°C

, 10

% L

IME

^

24W

EE

K8

CU

RE

D

AT

75° C '

i i

t i ii

46

8 1Q

44

6 8

1Q4

6 8

1Q2

2 4

6 8

1Q3

2

PORE

R

AD

IUS

nm

4 6

8 10

Figu

re 7

.44

Cumulative p

ore

volu

me a

gain

st p

ore

radius

for

soi

l -

10 wt%

lim

e specimens

cured

at 7

5°C

for

1 an

d 24

weeks

00 (Jl

in 5 O >

100 90

80

70

60

50-

ui oc O a. 40

h

30 20 10 0

24 W

EE

KS

C

UR

ED

AT

75*

C

10%

LIM

EB1

b<!

24 W

EE

KS

C

UR

ED

AT 2

5 C

i t

114

6

8 10

*i

i i

i i

i 11

4

6

8 10*

4 6

8 10

POR

E R

AD

IUS

nmFigure 7

.45

Cumulative p

ore

volume a

gainst p

ore

radius f

or s

oil

- 10

wt% l

ime

specimens

cured

for

24 w

eeks a

t 25

and 7

5°C

CD

ONO >

100-

90-

80-

70

60

50K

O

0.

4

0 30 20 10

B1 B2

B3

T——

! I

I I

f t»

——

——

—I—

——

I——

i I

I |

| II—

——

——

I——

—I—

—I

I I

I I

I I—

——

——

I——

—I—

—I

I I

I I

I I—

——

——

I——

—I—

—i

i i

i •

"

10%

LIM

E

24 W

EE

KS

C

UR

ED

AT

75°C

6% L

I ME

24 W

EE

KS

C

UR

ED

AT

75°C

2%

LIM

E

24 W

EE

KS

C

UR

ED

A

T 75

C

I I

I I

I I

II

I I

I I

I I

I I

I I

I

4 6

8 1Q

1 2

4 8

8 10

* 2

4 0

8 1Q

3 2

4 ft

8 1

0*

2 4

6 8

10

PORE

R

AD

IUS

nmFi

gure

7.46

Cumulative p

ore

volume a

gainst p

ore

radius f

or s

oil

- 2 wt%

lime

,soil -

6 w

t% l

ime

and

soil 1

0Wt% l

ime

spec

imen

s cured

for

24 w

eeks

at

75°C

CURED AT 75 C

O.14

LIME CONTENT %

Figure 7.47

Total pore volume against lime content for

specimens cured at 75°C for 1 and 24 weeks

87

-s 10

^ 8 O

0) ®

E u-~ 4

CURING TEMPERATURE :25 C

ffi< UJ2 cc

-610

8

6 10

LIME CONTENT %

14

Figure 7.48

Permeability against lime content for

specimens cured at 25°C for 1 and 24 weeks.

88

O

I

-510

8

6

CURING TEMPERATURE : 50 C

4I

CD < UJ5 cc

-610

8

6 10

LIME CONTENT %

14

Figure 7.49

Penneability against lime content for

specimens cured at 50 C for 1 and 24 weeks,

89

10r

8O«) (A

E o

CD< UJ5 ocUJo.

CURING TEMPERATURE : 75 C

B

6 10

LIME CONTENT %

14

Figure 7.50

Penneability against lime content for

specimens cured at 75°C for 1 and 24 weeks

90

- 5

108

s 6EJd 4

m<LU2 ccUJ -•o- 10

8

CURING TIME : 24WEEKS

UNTREATED SOIL

25" 50'

CURING TEMPERATURE

75°C

Figure 7.51

Permeability against curing temperature for soil-lime

specimens of various compositions cured for 24 weeks

91

o 0 (f)

E o

00< LU2 ccUJo.

1010 15 20 25 30

POROSITY %(PORES>40nm)

Figure 7.52

Permeability against the percentage porosity

contributed by pores of radius greater than 40 nm

92

140i

120

100

CURING TEMPERATURE : 25 C°

2% lime

E EUJ

UJx

80

60

40

20

INTREATED SOI L

12

CURING TIME (WEEK)

24

Figure 7.53

Frost heave against curing time for soil-lime cylinders

of various compositions cured at 25°C

93

EUJ

UJx

140

12O

100

80

60

40

20

CURING TEMPERATURE: 50 C°

2 % I i m e

UNTREATED SOIL

10%

12

CURING TIME (WEEK)

24

Figure 7.54


of various compositions cured at 50°C

94

E EUJ

UJ

140

120

100

80

60

40

20

CURING TEMPERATURE ! 75C

UNTREATED SOIL

•—— _6_%

10%

2% lime

12

CURING TIME (WEEK)

24

Figure 7.55


of various compositions cured at 75 C

95

120

100

E E

UJ

UJ

CURING TEMPERATURE: 25 c

20-

0-

2 6

LIME CONTENT %

Figure 7.56

Frost heave against lime content for soil-lime

cylinders cured for 1 and 24 weeks at 25 C

96

UJ

UJX

140

120

100

CURING TEMPERATURE: soc

I 80

I

60

40

20

LIME CONTENT %

10

Figure 7.57

Frost heave against lime content for soil-lime

cylinders cured for 1 and 12 weeks at 50°C

97

Figure 7.58

Frost heave and formation of ice lenses in soil-lime cylinders

(a) soil-2 wt% lime cured for 1 week at 75°C

(b) soil-6 wt% lime cured for 6 weeks at 25°C

(c) soil-10 wt% lime cured for 6 weeks at 50°C

98

DTG

20O 400 600

TEMPERATURE

800 1000 C

Figure 7.59

Thermogravimetric results for soil and cured soil-lime

samples, cured for 24 weeks at 50°C, (A) soil, (B) soil

and 6 wt% lime, (C) soil and 10 wt% lime and (D) soil and

14 wt% lime

99

o

o

rr n> n sH

- ff (V ff Q»

ri- >-«

<D 0) O O O to Ul

o

0°

I (D

•J

CO

NS

UM

ED

LI

ME

(w%

)

ro

^

o>

oo

oro

m

-°

iH

roO 1

O

H

S

O

.0(/>

O)

! e

o ^

?•

'O10

ro o>

I 14

oUJ QC

UJ

12

10

8

6

ui 4 oc

2 4 6 8 10

CONSUMED LIME(w%)

12

Figure 7.61

Plot of unconfined compressive strength against wt% "consumed

lime" for soil-lime specimens cured at 50 C for various times

101

Figure 7.62

Scanning electron micrograph of the fracture surface

of a 24 week (50°C) cured soil-14 wt% lime sample, X5000

102

o

o 1 A=10

"0*

|

nm

A CO CO CO CO CO

in

T ?CO CO

CM CO ? 7

20 (CO.K«)

Figure 7.63

Part of the X-ray diffractometer of soil-10 wt%

lime sample cured for 1.5 years at 75°C

103

Figure 7.64

Scanning electron micrographs of the fracture surface of

a 1 day (75°C) cured soil-10 wt% lime sample

(a) X2000, (b) X5000

104

Figure 7.65


a 3 week (75°C) cured soil-10 wt% lime sample

(a) X2000, (b) X5000

105

Figure 7.66


a 6 week (75°C) cured soil-10 wt% lime sample

(a) X2000, (b) X5000

106

Figure 7.67

(a) fracture surface of a 6 week (75°C) cured

soil - 10 wt% lime sample, X2000

(b) 4 week cured Portland cement, X5000

107

Figure 7.68

SEM and EDiAX results of the platelets particles formed

in a soil - 10 wt% lime sample, cured for 6 weeks at 75 C

108

(a)

Figure 7.69

Scanning electron micrographs of the fracture surface

of 12 week (75°C) cured soil-10 wt% lime sample

(a) X5000, (b) XlOOOO

109

Figure 7.70


of 6 month (75°C) cured soil-10 wt% lime sample

(a) X5000, (b) X10000

110

Figure 7.71


of 1 year (75°C) cured soil-10 wt% lime sample

(a) X10000, (b) X20000

111

(a)

Figure 7.72


of 18 month (75°C) cured soil-10 wt% lime sample

(a) X10000, (b) X10000

112

Figure 7.73


of 2 year (75°C) cured soil-10 wt% lime sample

(a) X5000, (b) X10000

113

0.38|um

Figure 7.74

Typical transmission electron micrographs showing gel morphology

after one year at 75°C for a soil-10 wt% lime sample

114

C —S—H gel from cured soil-lime

0.3 8/" m

a

Ca Al Si285 0.98 6.17

Figure 7.75

(a)Transmission electron micrograph of gel formed in soil

10 wt% lime composite cured in a moist environment at 75°C

for one year, (b) EDAX analysis of gel

115

0.2 wm

diffraction ring from ge|

d = 0.293 ±0.01 nm

Figure 7.76

Transmission electron micrograph of typical gel particle

together with its electron diffraction pattern

116

CaCO,

im

J80 (02 J04 {86

Ca1.00 Sl1.00 ^0.20

(b)

Figure 7.77

(a) TEM micrograph of gel formed in soil-10 wt% lime

composite cured in a moist environment at 75 C for 1 year

(b) EDAX analysis of gel at point X

117

0.6 p m (a)

{02 |64 (96

Ca0.62 Si 1.00 M0.71 Mg0.12 K0.09 Fe0.11

Figure 7.78

(a) TEM micrograph of gel formed in soil-10 wt% lime

composite cured in a moist environment at 75 C for 1 year


118

? 5 ,' ? 5 S J

038 [Um

eCa0.75 Si1.00

(a)

JB4 |9$

Fe0.45 K0.07

(b)

Figure 7.79

(a) TEM micrograph of gel formed in a soil-10 wt% lime

composite cured in a moist environment at 75°C for six weeks


119

im

182

^0.07 Si1.00 K0.04 Ca0.06

(04Ca '0.90 Si2.00 M0.

(80 (02 [64Ca1.08 Si2.00 ^0.42

I

Figure 7.80

(a) TEM micrograph of gel formed on the borders of

a quartz particle in a soil-10 wt% lime composite

cured at 75°C for 1 year

(b) EDAX analysis at point "A"

(c) EDAX analysis at point "B"

(d) EDAX analysis at point "C"

120

Figure 7.81


of a 12 week (75°C) cured refined Marl-20 wt% lime sample

(a) X5000, (b) X10000

121

200 400 600

TEMPERATURE

800 1000 C

Figure 7.82

KG traces for refined Marl - 20 wt% lime samples

cured for 1 day to 24 weeks at 75°C

122

CO CO O

H X OUJ

day cured

1 week

200 4OO 600 8OO 1000 C

TEMPERATURE

Figure 7.83

TG traces for refined Marl-20 wt% lime samples

cured for 1 day to 24 weeks at 75°C

123

100

CURING TIME (WEEKS)

Figure 7.84

Plot of reacted lime against curing time for

refined Marl - 20 wt% lime samples cured at 75 C

124

d « 0.280 + 0.01 nm

fee to2 104 tesSi1.00 Ca0.34 K0.10 Fe0.15

Figure 7.85

(a) TEM micrograph of gel formed in a refined Marl - 20 wt% lime

composite, cured for 6 weeks at 75°C

(b) Electron diffraction at Point X, (c) EDAX analysis at point X

125

im

d = 0.287 + 0.01 nm (b)

Figure 7.86

(a) TEM micrograph of gel formed in a

refined Marl - 20 wt% lime composite,

cured for 24 weeks at 75°C

(b) Electron diffraction at point "A"

(c) EDAX analysis at point "A"

(d) EDAX analysis at point "B"

(e) EDAX analysis at point "C"

|02^0.36 Si1.00 0.03

1AS KC I i la

(08 [92Ca0.65 Si 1.00

(C)

[34 |e 60.03

"0.89 Si1.00

(e)

126

§

to

8 a § 10 01 01 fll ft 01 n°

(V n ft (D a H- l-h 0)

O

ft

O ff

it B H- rt

(D

| 0)

CO

ro O

3 o 3

** 3 o o 3 r+ 9

— 3

3>

0

O 3 3

montmorillonlte

CO (A0

2UJ

16

20

untreated

lime treated

200 400 600

TEMPERATURE

800 1000 C

Figure 7.88

Thermogravimetric results for montmorillonite - 20 wt%

lime sample, cured at 75°C for 12 weeks

128

d - 0.287 + 0.01 nm (b) |B2 |04 (06

Ca0.67 Si1.00 M0.33 Na0.12 Mg0.09 Fe0.05

4-

Figure 7.89

(a) TEM micrograph of gel formed in a montmorillonite - 20 wt%

lime composite cured for 12 weeks at 75°C

(b) Electron diffraction at point X (c) EDAX analysis at point X

129

0.05

Figure 7.90

(a) TEM micrograph of gel formed in a montmorillonite - 20 wt%


(b) EDAX analysis at point X

130

kaolinite

29<Co.k<*)

k = lo n m

Figure 7.91

Parts of the X-ray diffractoroeter of kaolinite - 20 wt%

lime sample, cured for 12 weeks at 75 C

131

CO

SX O

8

12

16

TG

untreated

lime treated

200 4OO 60O 80O 1000 C

TEMPERATURE

Figure 7.92

Thennograviraetric results for untreated kaolinite and kaolinite-20 wt% lime sample, cured for 12 weeks at 75 C

132

d - 0.287 + 0.01 nm 06 |02 J84Ca0.20 S11.00 M0.83

Figure 7.93

(a) TEM micrograph of gel formed in a kaolinite - 20 wt% lime

composite cured for 12 weeks at 75°C (b) Electron diffraction

at point X (c) EDAX analysis at point X

133

M |B2 (64Ca0.40 Si1.00 ^0.86

Figure 7.94

(a) TEM micrograph of gel formed in a kaolinite-20 wt% lime

composite cured for 12 weeks at 75°C


134

M l« )B6Ca0.86 Si 1.00 ^0.85

Figure 7.95

(a) TEM micrograph of gel formed in a kaolinite - 20 wt%



135

illite

e<

1 A=10 nm

Figure 7.96

Part of the X-ray diffractometer of illite - 20 wt%

lime sample cured at 75°C for 12 weeks

136

0

a* 4CO COO 8

12O

i20

untreated

lime treated

200 400 600

TEMPERATURE

800 1000C

Figure 7.97

Thermogravimetric results for illite - 20 wt%

lime sample cured at 75°C for 12 weeks

137

Figure 7.98


illite - 20 wt% lime sample cured for 12 weeks at 75°C

(a) X 5000, (b) X 10000

138

Figure 7.99

Typical TEM-EDAX analysis of gel fonned in

illite - 20 wt% lime sample cured for 12 weeks at 75°C

(major composition : Ca^ ^g Si^ QQ Alg ^)

139

CHAPTER EIGHT

U-0.3593

Crystal structure of Ca(OH),: arrangement of linked Ca(OH)6 octahedra within a single layer. Parts of three rows of octahedra are shown. The lightly dotted faces of the octahedra are lying flat, with their points away from the observer. Each octahedron has a Ca*+ ion at it* centre and OH~ ions at each of its six apices; each OH~ ion is shared between three

octahedra.

Plan

Elevation

Crystal structure of a single layer of calcium hydroxide, full circles represent calcium atoms, and large circles, represent oxygen atoms; hydrogen atoms are not shown

Figure 8.1

Crystal structure of Ca(OH) 2 /

after Taylor [131]

140

Ideal 2 —dimensional

Si O net 2 5• Si o o

For Si—O= 0.16 nm

b= 0.905 nm

\

Ideal 2—dimensional

dioctahedral sheet

For « = AI , AI-O = 0.189nm

b= 0.801 nm

For • =AI (in Gibbsite)

b = 0-864n m

Figure 8.2

Representation of an idealized Si^Oc

sheet and the idealized dioctahedral sheet

(b)

Figure 8.3

SEM micrographs of a 24 week cured

soil-10 wt% lime sample at 75°C showing

exfoliation and breakdown of the clay layers

(a) X 5000, (b) X 10000

142

Figure 8.4

SEM-EDAX analysis at point "X"

in Figure 8.3(a)

143

H.O

2-2 —dimensional [si O]sheet

interlayer potassium »water

dioctahedral sheet of cations

SiO4 tetrahedron• om« llumlnium • utntllullon

(oy\ octahedron

<OH)~O mainly• Si4*

•!•<> Fe2 +

K(Fe.Mg,AI)2 (Al ,Si ^O

octahedral: tetrahe dral = 0.5

Figure 8.5

Representation of illite structure

144

CaO

H 2 0

C-S-H CH *CH;H

CH . .. -C-S-H/3

/ C-S-WATER-DEFICIENT REGION

cs Si 02

Figure 8.6

Phase development in the system CaO-SiO^-H-O

showing the course of cement-pozzolana-water reactions,

after Glasser and Marr [192]

145

fabric and strength of clays stabilized with lime …7.1 scanning electron micrograph of lime 41...

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