fundamentals of geopolymers

113
Fundamentals of Geopolymers By Dr. Radhakrishna Professor and Head – Civil Engg RV College of Engineering, Bengaluru 8 th June 2020 11.00AM Webinar Series Indian Concrete institute, Bengaluru Centre

Upload: others

Post on 03-Oct-2021

8 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Fundamentals of Geopolymers

Fundamentals of Geopolymers

By Dr. Radhakrishna

Professor and Head – Civil Engg

RV College of Engineering, Bengaluru

8th June 2020 11.00AM

Webinar Series

Indian Concrete institute, Bengaluru Centre

Page 2: Fundamentals of Geopolymers

Cement Concrete will remain as Very popular material

Good in compression More advantages

Per capita Usage is next only to water Each ton releases equal amount of CO2

Need of alternative material

2

Page 3: Fundamentals of Geopolymers

Portland cement • Most energy intensive

• consumes 4GJ per tonne of energy

• Major ingredient of concrete

• Less shelf life

Page 4: Fundamentals of Geopolymers

Cementicious Materials • Different cementicious composites -using

Industrial waste/Marginal

• Fly ash, GGBFS, Lime, Gypsum, etc.

• Potential to use as alternatives to OPC

• Using in construction = the best way to dispose

4

Page 5: Fundamentals of Geopolymers

Worldwide Carbon Emissions C

arb

on

(1

09 m

etri

c to

ns)

0

1

2

3

4

5

6

7

8

1750 1800 1850 1900 1950 2000 Year

Liquid fuel Total

Gas fuel Solid fuel

Page 6: Fundamentals of Geopolymers

Mitigation of Global Warming

• Conservation – Reduce energy needs

– Recycling

• Alternate energy sources – Nuclear

– Wind

– Geothermal

– Hydroelectric

– Solar

– Fusion?

Page 7: Fundamentals of Geopolymers

How it is possible in Construction industry?

7

Page 8: Fundamentals of Geopolymers

Replacement of OPC by fly ash in different materials

8

Page 9: Fundamentals of Geopolymers

What is geopolymer?

• Activation of natural materials – clay etc

• Geo = available in earth’s crust

• Polymerization – cementing material

• Low carbon foot prints

9

Page 10: Fundamentals of Geopolymers

Prof. Joseph Davidovtis

French Scientist

Pyramids in Egypt

Postulated a theory – 4500 years

Controversial

Page 11: Fundamentals of Geopolymers

Coal ash

India-Electricity- 65% coal burning

Coal reserves expected to last >100 years.

Fly ash

Page 12: Fundamentals of Geopolymers

Fly ash

By product of TPS Rich in Si and Al

Finer than cement Spherical in shape

Can replace cement 12

Page 13: Fundamentals of Geopolymers

ASTM Classification of Fly ash

Class F – Ca <5% - Anthracite coal

Not self cemeticious

Very common across World

Class C - Ca>15% - Lignite coal

Self cememnticous

Rare – Lot of commercial value

Page 14: Fundamentals of Geopolymers

Guidance documents used for fly ash quality assurance.

ACI 229R Controlled Low Strength Material (CLSM)

ASTM C 311 Sampling and Testing Fly Ash or Natural Pozzolans for Use as a Mineral Admixture in Portland Cement Concrete

AASHTO M 295 ASTM C 618

Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Portland Cement Concrete

ASTM C 593 Fly Ash and Other Pozzolans for Use With Lime

ASTM D 5239 Standard Practice for Characterizing Fly Ash for Use in Soil Stabilization

ASTM E 1861 Guide for the Use of Coal Combustion By-Products in Structural Fills

Page 15: Fundamentals of Geopolymers

Slag

Waste from Ferrous industry Quenched, ground, granulated – GGBS

Rich in Si, Al, Ca 15

Page 16: Fundamentals of Geopolymers

Metakaolin

Burnt clay at high temperature Highly reactive Contains Silica

Can replace cement Not economical

16

Page 17: Fundamentals of Geopolymers

Silica Fume

Contains >90 % Silica Finer than Fly ash – 1 micron

Condensed form Can replace cement

17

Page 18: Fundamentals of Geopolymers

Properties of binders

Binder Specific

Gravity

Percentage

Of Residue

left on 45µ

Loss on

Ignition

Chemical Composition in percentage

Al2O3 Fe2O3 SiO2 MgO SO3 Na2O Total

Chlorides

CaO

Fly Ash

(FA1)

2.35 0.00 0.9 31.23 1.5 61.12 0.75 0.53 1.35 0.06 3.20

Fly Ash

(FA2)

2.00 71.98 4.0 33.3 0.94 35.2 5.1 2.1 1.5 0.05 3.10

Fly Ash

(FA3)

2.40 9.8 0.9 33.8 0.91 35.0 5.0 2.0 1.5 0.02 3.10

Fly Ash

(FA4)

2.30 2.1 0.8 34.2

0.80 35.0 5.0 2.0 1.5 0.05 3.20

GGBFS 2.50 10.45 0.3 13.24 0.65 37.21 8.65 - - 0.003 37.23

Page 19: Fundamentals of Geopolymers

Ingredients of geopolymer mortar

Page 20: Fundamentals of Geopolymers

Activation

Page 21: Fundamentals of Geopolymers

Water

• Used to make alkaline solution

• Released during geopolymerrisation

• Not used for curing

Page 22: Fundamentals of Geopolymers

Making of Geopolymer

• Same process as cement composites

• Change in ingredients

• Cement --- Alumnino silicates

• Eg of Alumino silicates Fly ash

GGBS

Silica fume

Metakolin

Rice husk ash

Red mud etc - Locally available material

Page 23: Fundamentals of Geopolymers

Making of Geopolymer

• Aggregate is same

Water - Alkaline solution – 8-14 M

– Sodium hydroxide and sodium silicate

– Potassium hydroxide and Potassium silicates

Sodium salts +water - Alkaline solution

Page 24: Fundamentals of Geopolymers

Process of making

Page 25: Fundamentals of Geopolymers

Process - Contd

Page 26: Fundamentals of Geopolymers

Strength Development

• Fly ash class F

Geopolymerisation

At elevated temperature – 60 OC

• GGBS

Hydration

Thermal energy – not required

• Fly ash + GGBS

– Geopolymerisation+ Hydration

– Thermal energy – not required

Page 27: Fundamentals of Geopolymers

Molarity

• Concentration of alkaline solution

• NaOH = 40g/mol.

• 1 lithre of water +40g of NaOH = 1M

• For 12 M, 40x12=480g of NaOH in 1 l of water

• Ratio of NaOH/Na2O SiO2

Page 28: Fundamentals of Geopolymers

Alkaline solution

• Tap water + Sodium hydroxide + sodium silicate --- Alakaline solution

• Produces heat upto 80 Degree Celsius

• Stir and cool it

• Use after 24 hours.

Page 29: Fundamentals of Geopolymers

Precautions

• Highly alkaline + hot at early hours

• Not to touch with bare hand

• Use protective measures

• If it falls on skin - loss of skin

• Takes long time for healing

• Avoid falling of solution on

skin, ear, eye etc

Page 30: Fundamentals of Geopolymers

First Aid

• Immediately splash jet of water on affected area continuously

• Irritation stops in minutes

• If problem persists – Consult doctor

• Many researchers hide this info

Page 31: Fundamentals of Geopolymers

Eyes

Immediately wash eyes with clear water

Consult doctor

Don’t delay

Steroids my be used as prescribed

Page 32: Fundamentals of Geopolymers

Challenges Quality of fly ash - May not be

uniform

GGBS √

Sodium Hydroxide - Flakes

Sodium silicate – Solution

Solidification - Rock like

Trials are preferred

Page 33: Fundamentals of Geopolymers

Geopolymers

Page 34: Fundamentals of Geopolymers

Water – to – Cement ratio

• Water - Fluid

• Cement - Binder

• W/C - Fluid/binder ratio

• Ratio by weight

• Mortar ( masonry unit) – 0.15 to 0.3

• Plastering Mortar – 0.9 – 1.1

• Concrete – 0.3 to 0.6

Page 35: Fundamentals of Geopolymers

Forms of Geopolymers

Paste Mortar

Concrete Masonry

+ =

Fine aggregate

Page 36: Fundamentals of Geopolymers

Geopolymer paste

Fly ash + GGBS+ Alkaline Solution

Page 37: Fundamentals of Geopolymers

Studies on Geopolymer Paste

Alkaline fluid content – a constant function of respective

normal consistency

37

Series Designation, Binder Composition and Molarity of NaOH for Geopolymer Paste Series.

Series ID GP1 GP2 GP3 GP4 GP5 GP6 GP7 GP8 GP9 GP10 GP11

[FA:GGBS ] % 100:0 90:10 80:20 70:30 60:40 50:50 40:60 30:70 20:80 10:90 0:100

Molarity M of

NaOH

12 for GP1 to GP11 and 6, 8, 10 and 12 for GP4

Page 38: Fundamentals of Geopolymers

Studies on Geopolymer Paste contd…

Compressive Strength

Variation of Comp. strength - with age and GGBS content

38

0

5

10

15

20

25

30

35

40

0 5 10 15 20 25 30

GP11

GP10

GP9

GP8

GP7

GP6

GP5

GP4

GP3

GP2

GP1

Age [ Days ]

Ave

rage

Co

mp

ress

ive

Str

en

gth

[M

Pa]

M =12

y = 2.6382x + 7.5709

R² = 0.9886

y = 2.5718x - 2.8582

R² = 0.9825

y = 1.7291x - 3.2018

R² = 0.9768

-5

0

5

10

15

20

25

30

35

4028 days

7 days

1 day

Linear (28 days)

Linear (7 days)

Linear (1 day)

Ave

rage

Co

mp

ress

ive

Str

en

gth

[M

Pa]

M =12

Fly Ash / GGBS Content [ % ]

Page 39: Fundamentals of Geopolymers

Studies on Geopolymer Paste contd…

Evolution of micro-structure of GP paste GP4 with age

[fly ash to GGBS ratio of 70:30, 12M]

1 day Strength: 2.9 MPa 3 days Strength: 3.3 MPa 7 days Strength: 6.4 MPa

14 days Strength: 14.2 MPa 28 days Strength: 20.4 MPa

39

Page 40: Fundamentals of Geopolymers

… [fly ash to GGBS ratio of 70:30, 7 days]

6M Strength: 2.6 MPa 8M Strength: 4.8 MPa

10M Strength: 5.4 MPa 12M Strength: 6.5 MPa

40

Evolution of Micro structure with Molarity for GP4

Page 41: Fundamentals of Geopolymers

Findings on Paste

• Strength is more than OPC paste

• Setting Characteristics depends on many factors.

• Can be used for grouting – without curing

Page 42: Fundamentals of Geopolymers

Geopolymer Mortar

Page 43: Fundamentals of Geopolymers

Studies on Geopolymer Mortar.

Mortar Composition and Series Designation of the GeopolymerMortar for different fluid-binder ratios and mortar proportion.

43

Fluid-to-Binder Ratio [ F/B ] = 0.35 for GM-A Series and 0.20 for GM-B Series

Molarity [M] of Sodium Hydroxide : 14

Binder

Composition

[Fly ash : GGBS] %

Series Designation

Mortar Proportion

[Binder : Sand] 1 : 2.0

Mortar Proportion

[Binder : QD] 1 : 1.5

100 : 00 GM-A1 GM-B1

90 : 10 GM-A2 GM-B2

80 : 20 GM-A3 GM-B3

70 : 30 GM-A4 GM-B4

60 : 40 GM-A5 GM-B5

50 : 50 GM-A6 GM-B6

40 : 60 GM-A7 GM-B7

30 : 70 GM-A8 GM-B8

20 : 80 GM-A9 GM-B9

10 : 90 GM-A10 GM-B10

00 : 100 GM-A11 GM-B11

Page 44: Fundamentals of Geopolymers

Studies on Geopolymer Mortar. contd..

VARIATION OF STRENGTH WITH BINDER COMPOSITION AND AGE AT CONSTANT FLOW OF [75±5] %

Variation of strength w. r. t. fly ash-to-GGBS ratio

for different ages at constant flow of [75±5] %.

44

0

2

4

6

8

10

12

14

16

18

20

22

24

100/0 90/10 80/20 70/30 60/40 50/50 40/60 30/70 20/80 10/90. 0/100

28 Days

14 Days

7 Days

Series ID: GM-F M = 14 Flow = [75±5] % B:QD = 1:2

Avg

. co

mp

ress

ive

str

engt

h [

MP

a]

Fly ash/GGBS content [ % ]

Page 45: Fundamentals of Geopolymers

Studies on Geopolymer Mortar. contd..

VARIATION OF STRENGTH WITH MOLARITY OF NaOH

Variation of strength w. r. t. molarity of NaOH solution

in the alkaline fluid, for different ages.

45

0

1

2

3

4

5

6

6 8 10 12 14 16 18 20

28 Days

14 Days

7 Days

Ave

rage

Co

mp

ress

ive

Str

en

gth

(M

Pa)

Molarity M of NaOH

Series ID: GM-M FA:GGBS = 40:60 F/B = 0.20 B: QD = 1:1.5

Page 46: Fundamentals of Geopolymers

Studies on Geopolymer Mortar. contd..

VARIATION OF STRENGTH WITH MORTAR PROPORTION

Mortar Composition and the Series Designation

of the GP Mortar for different Mortar Proportion.

Variation of strength w. r. t. age [14 M]

46

[Fly ash : GGBS] % = 40 : 60

Molarity [M] of NaOH : 14

[ F/B ] = 0.40

Mortar Proportion

[Binder : QD] Series Designation

1 : 1.0 GM-P1

1 : 1.5 GM-P2

1 : 2.0 GM-P3

1 : 2.5 GM-P4

1 : 3.0 GM-P5

0

5

10

15

20

25

0 5 10 15 20 25 30

GM-P1

GM-P2

GM-P3

GM-P4

GM-P5

Age in days

Avg

. co

mp

ress

ive

str

en

gth

[M

Pa]

Series ID: GM-P F/B = 0.40 FA:GGBS = 40:60 M = 14

Page 47: Fundamentals of Geopolymers

Geopolymer composites Partially saturated

w/c ratio < 0.3 Solids + Liquid + Air Mortar Suitable for making bricks/blocks Requires compaction

Fully Saturated

w/c > 0.3 Solid + Liquid Concrete Suitable for structural material > 20 MPa May not require compaction

47

Page 48: Fundamentals of Geopolymers

Geopolymer Blocks Considered

• Manually made

• Hydraulic Press

Curing Conditions

Heat cured (without water)

Ambient (Without water)

Page 49: Fundamentals of Geopolymers

49

Materials mixed in dry condition

Page 50: Fundamentals of Geopolymers

50

Page 51: Fundamentals of Geopolymers

51 Alkaline fluid is added

Page 52: Fundamentals of Geopolymers

52

Page 53: Fundamentals of Geopolymers

53

Mixed to get homogeneous mix

Page 54: Fundamentals of Geopolymers

54 Required quantity of mortar - weighed

Page 55: Fundamentals of Geopolymers

Mridini Developed AT IISc for soil stabilized blocks 55

Page 56: Fundamentals of Geopolymers

56

Presses using lever - manually

Page 57: Fundamentals of Geopolymers

57 Mould is lubricated

Page 58: Fundamentals of Geopolymers

58

Page 59: Fundamentals of Geopolymers

59

Mould is filled with harsh mortar

Page 60: Fundamentals of Geopolymers

60

Mould is pressed with cover plate manually

Page 61: Fundamentals of Geopolymers

61

Fresh block is ejected

Page 62: Fundamentals of Geopolymers

62

Weight of the block is noted

Page 63: Fundamentals of Geopolymers

63 Neatly labeled

Page 64: Fundamentals of Geopolymers

64

Cured in open air

Page 65: Fundamentals of Geopolymers

65

Three Phase System Mortar

Solids + Liquids + Air (Binder & Aggregates) + Fluid + Voids

Page 66: Fundamentals of Geopolymers

66

Tested for Compression

Page 67: Fundamentals of Geopolymers

67 Block with crack – After testing

Page 68: Fundamentals of Geopolymers

68

Block making – Static and Vibro compaction

Page 69: Fundamentals of Geopolymers

69

Mould is filled with mortar

Page 70: Fundamentals of Geopolymers

70

Page 71: Fundamentals of Geopolymers

71

The mould is covered

Page 72: Fundamentals of Geopolymers

72 Compacted in hydraulic machine

Page 73: Fundamentals of Geopolymers

73

Block is taken out

Page 74: Fundamentals of Geopolymers

74

Cured in Open air

Page 75: Fundamentals of Geopolymers

75

Mass production of the blocks

Page 76: Fundamentals of Geopolymers

76

Blocks in open field

Page 77: Fundamentals of Geopolymers

77

Pavers stacked

Page 78: Fundamentals of Geopolymers

Blocks with different shape and size

CB1 CB2 CB3

PB1 PB2 PB3

78

Page 79: Fundamentals of Geopolymers

Sl no. Block ID Size (mm)

1 PB1 220 × 150 × 60

(outer to outer)

2 PB2 200 × 160 × 60

(outer to outer)

3 PB3 200 × 120 × 60

(outer to outer)

4 CB1 200 × 110 × 60

5 CB2 Cylinder, Dia = 38, Ht =

76

6 CB3 230 × 190 × 90

Dimensions of the blocks

79

Page 80: Fundamentals of Geopolymers

Ambient Cured Blocks No thermal input No traditional Curing No Demoulding Only compress and keep ready

Page 81: Fundamentals of Geopolymers

Heat Cured Geopolymer blocks

Page 82: Fundamentals of Geopolymers

Geopolymer Masonry Blocks

Heat Cured – Oven @60OC

for 24 hours

Ambient Cured – Open Air

Page 83: Fundamentals of Geopolymers

Strength Vs Fluid-to-binder ratio (Heat cured blocks)

10

12

14

16

18

20

22

24

26

28

0.125 0.15 0.175 0.2 0.225 0.25

Fluid-to-binder ratio

Co

mp

ress

ive

stre

ng

th (

MP

a)

10M-Sand-W-1Day

10M-Sand-W-3Days

10M -Sand-W-7Days

12M- Sand-W-1Day

12M-Sand- W-3Days

12M -Sand-W-7Days

14M-Sand -W-1Day

14M -Sand-W-3Days

14M -Sand-W-7Days

14M-QD-W-1Day

14M-QD-W-3Days

14M-QD-W-7Days

14M-QD-UW-1Day

14M- QD-UW-3 Days

14M-QD-UW-7Days

Page 84: Fundamentals of Geopolymers

Ambient Cured Geopolymer Blocks

Page 85: Fundamentals of Geopolymers

Parameters

• Age of the sample: 1, 3,7,14, 28, 56, 90, 120 and 180 days.

• Fly ash: FA1, FA2, FA3 and FA4. • Alkaline activator: Sodium hydroxide and potassium

hydroxide. • Ratio of binder-to-aggregate: 1:1, 1:2 and 1:3. • Degree of saturation: 40 and 60%. • Molarity of alkaline solution: 8, 10, 12 and 14 M. • Fine aggregate: Sand, quarry dust and pond ash. • Temperature: 25, 30, 40, 50, 60, 70 and 80oC. • Binder: fly ash, GGBFS, silica fume, metakaolin.

Page 86: Fundamentals of Geopolymers

1

2

3

4

5

6

7

8

9

10

11

1 10 100 1000Age (Days)

Co

mp

res

siv

e s

ren

gth

(M

Pa

)

f/b=0.200

f/b=0.225

f/b=0.250

f/b=0.275

f/b=0.300

Strength Development with age - Geopolymer blocks

86

Page 87: Fundamentals of Geopolymers

Strength Development with age

Page 88: Fundamentals of Geopolymers

Typical Stress- Strain Curve

Page 89: Fundamentals of Geopolymers

Modulus of Elasticity

Series

Id.

Avg.

ultimate

compressive

strength

[MPa]

0.25 x Avg.

ultimate

strength

(σ)[MPa]

Strain at stress

level of 0.25 x

avg. ult.

Strength (ε)

Secant

Modulus

(σ /ε) [MPa]

BR1 26.93 6.73 0.000406 16582.5

BR2 20.00 5.00 0.000580 8620.7

BR3 25.20 6.30 0.000354 17806.7

BL 12.63 3.16 0.000352 8977.3

Page 90: Fundamentals of Geopolymers

Weight loss with elevated temperature – 2 hours

Page 91: Fundamentals of Geopolymers

Durability Tests on Blocks

Loss of mass and water content as per

ASTM: D559–2003

Loss of mass - 2.0 %

Water absorption - 2.4%

91

Page 92: Fundamentals of Geopolymers

Geopolymer Blocks as masonry

Bricks

Solid blocks

Hollow blocks

Wallets

Page 93: Fundamentals of Geopolymers

Geopolymer Brick Wallets

CASTING OF GEOPOLYMER BRICKS WALLETES

Fig : Schematic Representation of Typical geopolymer brick

Wallete

Stretcher Bonded Geopolymer Brick Wallete

kept for Curing

Bricks- 8M NaOH bricks

Mortar- 1:6 cement: River sand

mortar of type M2 as per IS 1905-

1987

Bed & Head Joints - 10mm thick

Wallete dimensions- (hxbxt) =

1105mm X 1165mm X 107mm.

h/t ratio= 10.32

Page 94: Fundamentals of Geopolymers

Geopolymer Brick Wallets

TESTING ARRANGEMENT OF GEOPOLYMER BRICKS WALLETES

Fig: Ladder Arrangement for Eccentric

Loading

Fig: Ladder Arrangement for Geopolymer

brick Wallete

Loading assemblage was placed on the centre of bearing area of brick wallete.

For eccentric loading-18mm from the centre of bearing surface of the wallete.

Page 95: Fundamentals of Geopolymers

Geopolymer Solid Block Wallets

FAILURE PATTERN FOR THE GEOPOLYMER SOLID BLOCK WALLETE

Failure Pattern of Axially Loaded Wallete

Eccentrically Loaded Wallete

Vertical cracks developed from top.

Propagated till one third of the

height from top.

Spalling of cement joints at face of

wallete.

Page 96: Fundamentals of Geopolymers

Geopolymer Hollow Block Wallets

TESTING ARRANGEMENT OF GEOPOLYMER HOLLOW BLOCK WALLETES

Fig: Ladder Arrangement for Axially & Eccentrically Loaded Geopolymer Hollow Block Wallete

Eccentricity 25 mm from the centre of bearing surface of the wallete.

Page 97: Fundamentals of Geopolymers

Geopolymer Hollow Block Wallets

Table 23: RESULTS OF STRETCHER BONDED GEOPOLYMER HOLLOW BLOCK WALLETE

Type of

loading

Wallete

No

Load at first

crack (KN)

Ultimate load

(KN)

Compressive

strength (MPa)

Avg. Compressive

strength (MPa)

Axial

loading

1 300 425 2.27 2.31

2 380 442 2.36

Eccentric

loading

1 270 375 2.01 1.95

2 245 355 1.89

Normalized Stress-Strain curve for Axially Loaded Wallete Normalized Stress-Strain curve for Eccentrically Loaded Wallete

Strength of Eccentrically loaded block wallets is 84% of Axially loaded wallets.

Page 98: Fundamentals of Geopolymers

Pictures of Masonry Structure in Field

Page 99: Fundamentals of Geopolymers

Application of Geopolymer Masonry Units

During Construction

Geopolymer Model House

OBSERVATION MADE

No change in dimensions bricks and

the walls.

Brick edges remain sharp.

No erosion.

No pitting.

Less water absorptions.

No distress.

Even after two years there was no

sign of any deterioration of the walls

of the geopolymer brick model house.

The roof slab is casted after 24

months.

Page 100: Fundamentals of Geopolymers

Thermal Comfort during winter

Page 101: Fundamentals of Geopolymers

Geopolymer Concrete

Page 102: Fundamentals of Geopolymers

Studies on Geopolymer Concrete

Parameters Considered: For GPC(GC)

For Reference Concrete (NC) Concrete Proportion [OPC: QD : CA] 1 : 2.0: 3.0

Slump : (100±10) mm W/C = 0.6

102

Concrete Proportion [Binder : QD : CA] 1 : 2.0: 3.0

Sodium Silicate : Sodium Hydroxide :: 2 : 1

Molarity [M] of Sodium Hydroxide : 10

Slump : (100±10) mm.

Series

Designation

Binder Composition

[Fly ash : GGBS] % F/B ratio

GC 1 100 : 00 0.65

GC 2 80 : 20 0.65

GC 3 60 : 40 0.70

GC 4 40 : 60 0.75

GC 5 20 : 80 0.75

GC 6 00 : 100 0.75

Page 103: Fundamentals of Geopolymers

Studies on Geopolymer Concrete. contd.. MASS DENSITY: For GC, 2424-2516 kg/cum

For NC, 2504-2550 kg/cum

COMPRESSIVE STRENGTH:

Variation w. r. t. fly ash-GGBS Variation w. r. t. age.

103

0

10

20

30

40

50

60

70

90 days

56 days

28 days

7 days

3 days

Co

mp

ress

ive

Str

engt

h [

MP

a]

Fly ash/GGBS content [%]

Mix Proportion 1 : 2 : 3

0

10

20

30

40

50

60

70

0 20 40 60 80 100

GC 6

GC 5

GC 4

GC 3

GC 2

NC

GC 1

Age [Days]

Mix Proportion 1 : 2 : 3

Co

mp

ress

ive

Str

en

gth

[ M

Pa

]

Page 104: Fundamentals of Geopolymers

Studies on Geopolymer Concrete. contd..

SPLIT TENSILE STRENGTH:

Variation w. r. t. fly ash-GGBS Variation w. r. t. age.

104

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

90 days

56 days

28 days

7 days

3 days

Fly ash/GGBS content [%]

Mix Proportion 1 : 2 : 3

Split

Ten

sile

Str

engt

h [

MP

a ]

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 20 40 60 80 100

GC 6

GC 5

GC 4

GC 3

NC

GC 2

GC 1

Mix Proportion 1 : 2 : 3

Split

Ten

sile

Str

engt

h [

MP

a]

Age [Days]

Page 105: Fundamentals of Geopolymers

Studies on Geopolymer Concrete. contd..

FLEXURAL STRENGTH:

Variation w. r. t. fly ash-GGBS Variation w. r. t. age.

105

0

1

2

3

4

5

6

7

90 days

56 days

28 days

7 days

3 days

Fly ash/GGBS Content [%]

Fle

xura

l St

ren

gth

[ M

Pa

]

Mix Proportion 1 : 2 : 3

0

1

2

3

4

5

6

7

0 20 40 60 80 100

GC 6

GC 5

GC 4

GC 3

GC 2

NC

GC 1

Fle

xura

l St

ren

gth

[M

Pa]

Age [Days]

Mix proportion 1 : 2 : 3

Page 106: Fundamentals of Geopolymers

Studies on Geopolymer Concrete. contd..

SHEAR STRENGTH: {Bairagi and Modhera [134] and Baruah and Talukdar [135]}

Variation w. r. t. fly ash-GGBS Variation w. r. t. age.

106

0

1

2

3

4

5

90 days

56 days

28 days

7 days

3 days

Mix Proportion 1 : 2 : 3

Fly ash/GGBS Content [ % ]

She

ar S

tren

gth

[ M

Pa

]

0

1

2

3

4

5

6

7

0 20 40 60 80 100

NC

GC 6

GC 5

GC 4

GC 3

GC 2

GC 1

Shea

r St

ren

gth

[M

Pa]

Mix Proportion 1 : 2 : 3

Age [ Days ]

Page 107: Fundamentals of Geopolymers

Studies on Geopolymer Concrete. contd..

IMPACT STRENGTH: [Schruder’s Impact Testing]

Specimen Size =150mm dia. and 60 mm thick

Impact Energy = w.h.n

w = 45.4 N, h = 0.457 m., n = No. of blows to cause the

failure.

107

600

800

1000

1200

1400

1600

1800

final failure

first crack

Mix Proportion 1 : 2 : 3

Imp

act

En

ergy

[N

-m]

Fly ash/GGBS Content [%]

Page 108: Fundamentals of Geopolymers

Studies on Geopolymer Concrete. contd..

108

0

2

4

6

8

10

12

14

16

18

20

0 0.1 0.2 0.3 0.4 0.5

Specimen 1 GPC

Specimen 2 GPC

Mix Proportion 1 : 2 : 3 ; Geopolymer Concrete Fly ash/GGBS = 70/30

Bo

nd

St

ress

[M

Pa]

Slip [mm]

0

1

2

3

4

5

6

7

8

9

0 0.1 0.2 0.3 0.4 0.5 0.6

Specimen 1 NC

Specimen 2 NC

Bo

nd

Str

ess

[ M

Pa

]

Slip [ mm ]

Mix Proportion 1 : 2 : 3 ; Reference Concrete

Bond stress v/s relative bar slip for GP Concrete Bond stress v/s relative bar slip for Ref. Concrete

PULL-OUT STRENGTH

Page 109: Fundamentals of Geopolymers

Studies on Geopolymer Concrete. contd..

Typical S-S curve for GP concrete Normalized S-S curve for GP concrete

Ult.(cylinder) compr. strength: 31.1 MPa Avg. ult.(cylinder) compr. strength: 32.53 MPa

109

y = -4E+06x2 + 21443x R² = 0.9595

0

5

10

15

20

25

30

35

0 0.001 0.002 0.003 0.004

Typical Stress Strain Curve for GPC

Mix Proportion 1 : 2 : 3 ; M=10 Fly ash/GGBS = 70/30 ; F/B = 0.65 Sod. Silicate: Sod. Hydroxide = 2 : 1

Strain

Co

mp

ress

ive

Str

ess

[ M

Pa

]

y = -1E+07x2 + 19295x R² = 0.849

0

5

10

15

20

25

30

35

0.0000 0.0010 0.0020 0.0030 0.0040

Normalized Stress Strain Curve for GPC

Mix Proportion 1 : 2 : 3 ; M = 10 Fly ash/GGBS = 70/30 ; F/B = 0.65 Sod. Silicate : Sod. Hydroxide = 2:1

No

rmal

ized

Str

ess

[M

Pa]

Normalized Strain

Page 110: Fundamentals of Geopolymers

Comparison

Conventional • Strength – Hydration

• Cement is binder

• Water/Stream curing

• Water is used for mixing

• Definite procedure for mix design

Geopolymer • Strength – Geopolymerisation

+hydration

• Fly ash, GGBS….. Are binders

• Thermal curing – if only fly ash

• Alkaline solution is sued

• Developing stage

Page 111: Fundamentals of Geopolymers

Concluding Remarks

• Geopolymers can be developed in line with

Portland cement products

• High compressive strength, Durable

• Used for special applications

– Precast industry

– Fast grouting

– High early strength masonry units

– Lining of furnace

Page 112: Fundamentals of Geopolymers

Concluding Remarks

Geopolymer Concrete Satisfy

– Slump

– Compressive Strength

– Split tensile Strength

– Flexural Strength

– Impact Strength

– Shear Strength

With out OPC and Curing

Page 113: Fundamentals of Geopolymers

113

THANK YOU

For any questions:

E mail : [email protected]

Ph: 9886127398