1

WAYS AND TECHNOLOGIES AVAILABLE FOR OPTIMUM

UTILIZATION

2

DEVELOPMENT OF GEOPOLYMER CONCRETE PRODUCTS

Dr. C. Antony JeyaseharProfessor of Civil and Structural Engineering

Dr. S. ThirugnanasambandamAssociate Professor of Civil and Structural Engineering.

Annamalai UniversityAnnamalainagar-608002

Current Scenario in Concrete ProductionDemand increases vastly for raw materials.

Difficult to produce concrete due to continuous fluctuations in

availability of raw materials.

Frequent hikes in cost prices of the raw materials of concrete due

to their inconsistent availability.

Contributing to global warming by using cement as a raw material

for concrete.

Need for an alternative raw materials for making concrete - eco

friendly. 4

Ordinary Portland Cement – Frontline Supporter of Global Warming

Deadly Consumer of natural resources.

Creator of severe causes for environment imbalance.

Important contributor to global warming by emitting more

CO2 to atmosphere.

Intakes high amount of energy for production.

Utiliser of water for cooling at the stage of clinker.

Solution ?????5

Cement ProductionProcess of Manufacturing

of CementEmission of Carbon

dioxide

6

6

Gas pipeline from Iran, discouraged by U.S.

Coal supplies for 200 years, but high/ash, low

calorie value

Oil discovery by Cairn Energy in 2004; India’s demand will outstrip

supply

Gas discovery by Reliance in 2003 but

will service only fraction of India’s

power needs

Tarapur- India’s “civilian” nuclear reactor requires

refueling

Kakrapar- World’s first thorium-based nuclear

reactor

Gas pipeline from Turkmenistan, through

Pakistan, but questionable reserves

Gas pipeline from Myanmar through Bangladesh discouraged by U.S.

Hydro-Electric Dam at Narmada constrained by

problems with environment

Ron Somers, (U.S.-India Business Council), India Energy Conference,

Houston, Jun 2006

India’s Energy Security ChallengeIndia’s Energy Security Challenge

8

Global CO2 emissionsWorld Carbon Dioxide Emission in Million Metric Tons (1980 to 2050*)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

1980 1990 2003 2010 2020 2025 2050

65 Billion Tons by 2050

Mill

ion

Met

ric T

ons

Boston Analytics Research1. Energy Information Administration

(http://www.eia.doe.gov)

Year

• Use of geopolymer concrete reduces the release of CO2 in the atmosphere

Available Resources

We cannot continue to throw awaymountains of fly ash and slagBut will there always be suchmountains?

9

Re-Arranging the Equation

Power Generation Refinery/Chemical industryCement Production 10

Re-Arranging the Equation

+

11

Necessity of Geopolymer ConcreteTo produce Eco-Friendly concrete.

To reduce the utilisation of Ordinary Portland Cement.

To reduce the hazardous effects of industrial by-products by using themin making of concrete.

To reduce the mining of natural resources like limestone, clay etc.,

To save the loss of high energy used in cement industries.

To minimise the high utilisation of water during and after the productionof concrete.

To reduce global warming as much as possible.

To gift our future generations a safe planet.12

Geopolymers The term geopolymer was coined by Joseph Davidovits in 1978.

The geopolymers are mineral binder with chemical composition similar to

zeolites but with amorphous microstructure.

Geeopolymer was also chemically designated as ‘Poly(sialate)’ by Joseph

Davidovits.

Sialate is an abbreviation for silicon – oxo – aluminate.

Geopolymers are generally based on silico – aluminate.

Empirical formula for Poly(sialates) is given by : Mn (-(SiO2)z – AlO2)n .

wH2O

M = Monovalent cation such as Potassium or Sodium.

n = Degree of polycondensation and z = 1, 2,3 or higher upto 32. 13

Main Constituents of Geopolymers The significant constituents of geopolymers are the source

material and the alkaline activator solution.

The source materials should be rich in Silicon (Si) andAluminium (Al).

The source materials are available naturally in the form ofminerals and alternatively in the form of by-products.

Natural minerals : Kaolinite, clays, micas, spinel and etc.,

By-products : Fly ash, silica fume, slag, rice husk ash, red mudand etc.,

The alkaline solutions are from alkali soluble metals usuallysodium or potassium based. 14

Materials used for Geopolymer Concrete

Among all other source materials low calcium fly ash is mainlyused all around world.Low calcium fly ash.

A by-product obtained from burning of coal from the thermalpower plants.

Ground Granulated Blast Furnace Slag (GGBS).

A by-product obtained from steel industries.

Alkaline solutionSodium hydroxide or Potassium hydroxide.Sodium silicate solution or Potassium silicate solution.

Coarse Aggregate: Crushed stones /gravels.

Fine Aggregate : River sand / M Sand. 15

Applications of Geopolymers based on their Si : Al ratio

Si:Al ratio Applications

1- Can be used to make bricks.- Can be used for producing ceramics.- Can be used as fire protection where there is a frequent

chances of fire accidents.2 - Low CO2 cements and concretes.

- Radioactive and toxic waste encapsulation.3 - Fire protection fibre glass composite.

- Foundry equipment’s – Heat resistant composites, 200o C to 1000o C.

- Tooling for aeronautics titanium process.>3 - Sealants for industry, 200o C to 600o C.

- Tooling for aeronautics SPF Aluminium.20 -35 - Fire resistant and heat resistant fibre composites

16

Materials used for Geopolymer Concrete

17

CHEMICAL COMPOSITION OF CEMENT AND FLY ASH

Materail SiO2 Al2O3 Fe 2O3 CaO Mgo SO3 Na2O

Cement 19.33 5.66 2.66 63.07 0.36 3.38 0.14

Flyash 66.61 27.57 3.14 1.32 1.36 - -

Preparation of Alkaline SolutionThe alkaline solution should be prepared 24 hours prior to casting of

GPC Concrete.

Step 1 : The required amount of NaOH pellets are mixed with requiredamount of H2O.

Step 2 : Na2SiO3 solutions are mixed with NaOH solution.

Step 3 : The solution is mixed thoroughly and leave it for 24 hours.

The solution is kept idle for 24 hours is to developing the polymerisationprocess.

After 24 hours the alkaline solution is ready for making geopolymerconcrete.

In place of NaOH pellets and Na2SiO3 solutions, KOH pellets andK2SiO3 solution may be used for making alkaline solution. 19

Preparation of Alkaline Solution

20

Mixture Proportions of Geopolymer ConcreteThe main difference between OPC concrete and geopolymer concrete is the

binder.Fly ash(silicon and aluminium oxides) + alkaline solution → geopolymerpaste.Geopolymer paste binds the fine aggregate, coarse aggregate, other

unreacted materials.75 - 80 % of mass filled by aggregates (similar to cement concrete).The mixture can be designed using the same designing tool used for OPC

concrete.The alkaline solution influences the strength of geopolymer concrete.The concentrations of alkaline solution : 8M – 16M.8M of alkaline solution is sufficient to get concrete with normal strength.Water to geopolymer solids ratio influences the strength and workability of

the GPC. 21

Mixing & Casting of Geopolymer ConcreteA pan mixer was used for mixing of geopolymer concrete.The aggregates were prepared in saturated-surface-dry (SSD)

conditions.Step 1 : Fly ash was first mixed (dry) together with GGBS in pan

mixer for 2 minutes.Step 2 : Sand was placed in the pan mixer and the mix is continued

for another 2 minutes.Step 3 : Coarse aggregate is added to the mix and allowed to mix

for another 2 minutes.Step 4 : Finally the alkaline solution was added and the mix was

continued for 4 minutes.Step 5 : The workability of the geopolymer concrete should be

tested.Step 6 : The Geopolymer concrete can be cast in required moulds

to get specimens.22

Mixing of Geopolymer Concrete

23

Curing of Geopolymer ConcreteTypes of curing used:

Steam curing or hot air oven curing.

Ambient Curing. (Sunlight/room temperature)

Steam curing is required when GGBS is not added with fly ash.

Rest Period: 1 day.

Curing Period : 24 hours (1 day).

Curing temperature : 60oC (Steam/Hot air oven curing).

If GGBS is added ambient curing is sufficient to attain required

strength. 24

Steam Curing Chamber-GPC Concrete

Steam Curing Chamber-Open View Steam Curing Chamber-Closed View25

CASE STUDY - IM 20 grade concrete obtained using IS:10262-2009 was used (1:1.7:3.1) with a partialmodification of replacement of cement & water by fly ash & alkaline solutions.

Sl. No.

Mix Ratio Flyashkg.

Fine Agg. kg.

Coarse Agg. kg.

NaOH Solution Sodium Silicate

kg.

Sodium Silicate / Sodium

Hydroxide

(Sodium Silicate + Sodium Hydroxide)

/ FlyashMasskg.

Molarity

1 1:1:7:3.1 414 704 1283 17.02 8 M 133 2.5 0.45

Constituents of geopolymer concrete (Per 1m3)

Sl. No. Mix Ratio Molarity of NaOH

Solution

Slump mm

Curing Method

Curing Time

Curing Temp

Average Comp.

Strength N/mm2

1 1:1.7:3.1 8 M 120 steam 24 Hours 60ºC 30.702 1:1.7:3.1 10 M 105 steam 24 Hours 60ºC 32.53 1:1.7:3.1 12 M 85 steam 24 Hours 60ºC 37.5

Workability and strength properties

27

Sl. No.

Molarities of NaOH

AAS/Fly ash Ratio

Cube compressive

strength (N/mm2)

Cube Tensile

strength (N/mm2)

Cylinder compressive

strength (N/mm2)

Cylinder split tensile

strength (N/mm2)

123

8M10M12M

0.4049.5048.3346.72

9.1810.228.63

36.1835.8334.92

4.664.133.96

456

8M10M12M

0.4550.0249.1347.24

9.3710.568.69

37.3636.2335.67

5.134.784.02

789

8M10M12M

0.5052.0850.7349.26

9.8610.888.93

38.7237.0036.45

5.484.974.24

101112

8M10M12M

0.5549.7548.6347.84

9.0210.138.09

36.2735.5436.13

4.584.173.85

Compressive and Tensile Strength for Cubes and Cylinders

CASE STUDY – IIA mix ratio 1:1.3:2.7 (1 fly ash: 1.3 fine aggregate: 2.7 coarse aggregate)had been obtained for a cube compressive strength of 40 N/mm2 . In thisstudy, various concentrations of NaOH solutions 8M, 10M and 12M wereused along with different Alkali Activator Solution (AAS) / fly ash ratios 0.40,0.45, 0.50 and 0.55.

28

Geopolymer concrete Beams Totally five beams were cast and tested in the laboratory over an

effective span of 3000 mm.

Four geopolymer concrete beams were tested until failure; theremaining one beam was used as a Reinforced Cement Concrete(RCC) control specimen.

The beams were designed as under reinforced section, reinforcedwith 2-Y12 at bottom, 2-Y10 at top using 6 mm diameter stirrups at50 mm c/c and Fe 415 grade steel was used.

The geopolymer concrete mix proportion was 1:1.3:2.70 with differentAAS/fly ash ratio 0.4, 0.45, 0.5 and 0.55. For RCC beam, OrdinaryPortland Cement (OPC) 53 grade, natural river sand conformingZone III (IS 383-1970) and coarse angular aggregate of 20 mm wereused as the concrete ingredients.

The specimens (with the mould) were cured using steam curing.

Geopolymer concrete Beams

Testing of Geopolymer BeamsCrack pattern on Geopolymer

Beams

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Test results of Geopolymer Beams

Load – Deflection Curve

30

Developments in Geopolymer concretePost –Tensioned of Geopolymer Beams

Arrangement of Duct before Casting

Casting of Post-Tensioned Beam

Crack Pattern on GPC Post – Tensioned Beam 31

Test results of Post- Tensioned Geopolymer Beams

Load – Deflection Curve for OPC Post – Tensioned Beam

Load – Deflection Curve for GPC Post-tensioned Beam

32

Developments in Geopolymer concrete

Pre –tensioning of geopolymer sleepers

Pre – tensioned geopolymer sleepers after casting

33

Developments in Geopolymer concrete

Testing of Pre- tensioned geopolymer railway sleepers

Crack pattern of Pre – tensioned geopolymer railway sleepers34

Test results of Pre- Tensioned Geopolymer Railway Sleepers

Load – Deflection Curve for OPC Pre – Tensioned Sleepers

Load – Deflection Curve for GPC Pre-Tensioned Sleepers

35

36

GGBS Fly ash Sand Coarse Aggregate AlkalineSolution

Constituents of Geopolymer Concrete – Ambient Curing

Ambient Curing of Geopolymer ConcreteThe Ordinary Portland Cement concrete needs water curing during

hydration process.

In GPC the water is expelled during polymerization process and there is

no need for water curing.

So ambient curing is opted for GPC and it was proved that ambient

curing is sufficient for GPC.

Ambient curing has more benefits than any other curing methods.

The GPC cubes were cast and cured in ambient temperature for 24 hours.

The day time temperature varies between 30 to 35 degree Celsius and

night time temperature varies between 25 to 30 degree Celsius.37

Ambient Curing of GPC Concrete

Casting of Geopolymer Concrete Cube Specimens

38

Ambient curing of cube specimens

39

Reinforcement Grills for Beams

Casting of Geopolymer Concrete Beam Specimens

40

Ambient curing of Beams Specimens

41

Crack Pattern of Conventional Cement Concrete Beam

Crack Pattern of Geopolymer Concrete Beam

42

0

5

10

15

20

25

30

35

40

45

50

0 10 20 30 40 50 60 70 80 90

Loa

d in

kN

Deflection in mm

CB-I GB-I

Comparison of Load Deflection Behaviour of Conventional Cement Concrete and GPC Beams

Sl. No. Beam Designation

Load at Different Stage (kN)Deflection (mm)

First Crack Yield Ultimate First

Crack Yield Ultimate

1 CBI 10 25 42.5 6.2 22.4 793 GBI 12.5 27.5 45 4 24.6 82

Test Results of Concrete and GPC Beams

Railway Sleepers

43

Pretensioning of Strands Casting of GPC Sleeper De Tensioning of Strands

44

Ambient Curing of GPC Sleeper

Crack Pattern of GPC Sleeper

45

Load - Deflection curve for Cement Concrete and GPC Sleepers

Cement Concrete Sleeper Geopolymer Concrete Sleeper

First crack Load in kN

Yield Load in

kN

Ultimate stageFirst

Crack Load in

kN

Yield Load in kN

Ultimate stage

Load in kN Deflection in mm

Load inkN

Deflection in mm

90 123 290 32 60 182 320 49

Experimental Results of Railway Sleepers

Ferrogeopolymer – Grill Mesh

Ferrogeopolymer Water Pipes After Casting

46

Ferrogeopolymer pipes

Peak load = 0.5 kNYield stress = 390 MPaUltimate tensile stress = 500 MPa

Tensile Strength Test

Expended Wire Mesh

Welded Wire Mesh

Testing of ferrogeopolymer water pipes

Ferrogeopolymer water pipes crack pattern

48

Sl. No Type of Pipe Load at First Crack (kN)

Ultimate Load (kN)

Crack Width(mm)

1 Ferrocement pipe 10 40 0.01

2 Ferrogeopolymer pipe 22.5 50 0.01

3 Commercial pipe 5 8.3 0.01

Test Results of pipes

Developments in Geopolymer concrete

Ferro-geopolymer channels for Roofing Systems.

Ferro-geopolymer channels for roofing system 49

50

Load-Deflection Curve of Ferrocement, Ferrogeopolymer Channel

Sl. No. Ferrocement Channel Ferrogeopolymer Channel1 First crack load = 4.167 kN First crack load = 4.99 kN2 Ultimate load = 25.5 kN Ultimate load = 27.50 kN3 Deflection at first crack load =

1.8 mm Deformation at first crack load = 3.4 mm

4 Ultimate deflection = 29mm Ultimate deflection = 58mm

Test Results of Channels

Developments in Geopolymer concreteFerro-geopolymer

Dome after Casting

Crack Patterns Ferrogeopolymer

DomeTesting of Ferro-

geopolymer Dome

51

52

Des

igna

tion

of

Dom

e

Firs

t C

rack

L

oad(

kN)

Ulti

mat

e L

oad

(kN

) Displacement at First Crack Load (mm)

Displacement at Ultimate Load (mm)

HD1 VD2 HD3 VD4 HD1 VD2 HD3 VD4FCD1 60 95 0.15 1.99 0.37 0.39 0.55 3.01 0.44 0.69

FGPD1 45 160 0.08 1.68 0.39 0.97 0.48 4.92 1.69 5.47

Test Results of Domes

HD1 – Dial gauge placed horizontally at 150mm from baseVD2 – Dial gauge placed vertically at 300mm from baseHD3 – Dial gauge placed horizontally at 250mm from baseVD4 – Dial gauge placed vertically at 400mm from base

Designation of Dome Service Load (kN) Energy Absorption

(kNmm) Ductility Ratio

FCD1 57.79 137.5 1.76

FGPD1 98.49 420.57 5.6

Service Load, Energy Absorption and Ductility Ratio of Domes

Route to Geopolymer Bricks

53

CLAY BRICKS (Firing method)

FLY ASH BRICKS (Cementing method)

GEOPOLYMER BRICKS (Geopolymer method)

FLY ASH BRICKS CLAY BRICKS

Geopolymer Bricks

54

Sodium hydroxide Sodium silicate Activated solution Fly ash and GGBS

Bricks in Mould Curing

Compression TestingWater Absorption Testing Acid Resistance Testing

Fine Aggregate

Geopolymer Bricks

55

Sl. No. NaOH FA : GGBS Curing

Average Compressive

Strength (MPa)

1 6M 50 : 50 Oven 16.50

2 6M 50 : 50 Ambient 14.80

STRENGTH OF GEOPOLYMER BRICKS

SI. No

Types of BricksAverage Percentage of Water

Absorption (%)

1 Geopolymer Brick 4.06

2 Clay Brick 15.29

WATER ABSORPTION OF GEOPOLYMER BRICKS

ACID RESISTANCE TEST RESULT

Sl. No.

Types of Brick

Loss of Weight(%)

Loss of Compressive Strength (%)

H2SO4(1%)

HCL(3%)

H2SO4(1%)

HCL(3%)

1 Conventional 2.40 4.42 23.61 24.05

2 Geopolymer 2.26 1.02 18.96 5.07

56

Comparing the Geopolymer Brick and Conventional Bricks

Sl.No Type of bricksWater

absorption (%)

As per IS Code[ IS: 1077:1992 ]

Recommendation

1 Convention Bricks 15.3 1077:1992 ] Maximum allowable water absorption percentage of Brick : 20 %2 Fly ash Bricks 15

3 Geopolymer Bricks 4

Sl.No.

Concentration of

NaOH

FA : GGBS%

CuringAverage

Compressive Strength

(N/mm2)

As per IS Code [ IS: 3495:1992 ]

Recommendation

1 6M 50 : 50 Ambient 14.80minimum Strength of

Brick : 3.5 N/mm2

Strength of Geopolymer Brick

57

Geopolymer Clay Bricks

Average compressive strength of geopolymer clay brick is 6.88 MPa.

58

Types of Blocks% of Weight Loss % of Compressive Strength

LossHCL(3%) H2SO4(1%) HCL(3%) H2SO4(1%)

Conventional blocks 1.88 0.97 16.34 21.20

Geopolymer blocks 0.47 0.35 5.01 5.28

TYPES OF BLOCKS

PERCENTAGE INCREASE IN WATER

Conventional blocks 6.059Geopolymer blocks 1.285

Acid Resistance Test

Water Absorption Test

GEOPOLYMER CONCRETE HOLLOW BLOCKS

GEOPOLYMER CONCRETE USING M SAND

Mix Proportioning of M30 & M40 Grade Conventional Concrete

Grade of Concrete M 30 M 40

Mix Proportion 1 : 2.11 : 3.37 1 : 1.63 : 2.64

Cement(kg/m3) 350 430

Fine Aggregate(kg/m3) 737.568 699.660

Coarse Aggregate(kg/m3) 1178.064 1136.430

Water Content(kg/m3) 165 165

W/C Ratio(%) 0.47 0.38

Slump(mm) 60 70

Mix Proportioning of M30 Grade Geopolymer Concrete

Grade of Concrete M 30

Mix Proportion 1 : 2.12 : 3.37

Cementitious material (Fly ash + GGBS) (kg/m3) 370.370

Fly ash : GGBS 50 : 50

Fine Aggregate (kg/m3) 781.481

Coarse Aggregate (kg/m3) 1248.150

20 mm Aggregate 60 % 12.5 mm Aggregate 40 %

Sodium Hydroxide pellets (NaOH) (kg/m3) 15.92

Sodium Silicate solution (Na2SiO3) (kg/m3) 124.334

Water Content (kg/m3) 33.823

Alkaline Solution/(Fly ash+ GGBS) Ratio (%) 0.47Super Plasticizer % 1.2

Mix Proportioning of M40 Grade Geopolymer Concrete

Grade of Concrete M 40

Mix Proportion 1 : 1.63 : 2.64

Cementitious material (Fly ash + GGBS) (kg/m3) 455.407

Fly ash : GGBS 50 : 50

Fine Aggregate (kg/m3) 742.32

Coarse Aggregate (kg/m3) 1202.274

20 mm Aggregate 60 % 12.5 mm Aggregate 40 %

Sodium Hydroxide pellets (NaOH) (kg/m3) 19.80Sodium Silicate solution (Na2SiO3) (kg/m3) 123.64

Water Content (kg/m3) 29.676

Alkaline Solution/(Fly ash+ GGBS) Ratio (%) 0.38Super Plasticizer (%) 1.5

Casting & Testing of Conventional Concrete Specimens

Fresh Conventional Concrete

Slump Test

Casting of Conventional Concrete cube Specimen Compression Testing of CC Cube Specimen

Casting & Testing of Geopolymer Concrete Specimens

Fresh Geopolymer Concrete

Casting of Geopolymer Concrete

Testing of Geopolymer Concrete cube Specimen

Ambient Curing of Geopolymer Concrete

Mixing of Geopolymer Concrete

Compressive Strength ofConventional Concrete Cube Specimen

Grade of Concrete M 30 M 40

7 days StrengthN/mm² 31.67 35.73

14 days StrengthN/mm² 35.73 43.20

28 days StrengthN/mm² 38.82 48.41

Compressive Strength of M30 Grade Geopolymer Concrete Cube Specimen

Grade of Concrete M30

3 Days Compressive Strength of GPC with River Sand

N/mm²39.50

3 Days Compressive Strength of GPC with M - SandN/mm²

43.77

Compressive Strength of M40 Grade Geopolymer Concrete Cube Specimen

Grade of Concrete M40

3 Days Compressive Strength of GPC with River Sand

N/mm²55.03

3 Days Compressive Strength of GPC with M - SandN/mm²

61.82

M30 Grade Concrete

Comparison of M30 concrete CC vs GPC(S) vs GPC(M-S)

M40 Grade Concrete

Comparison of M40 concrete CC vs GPC(S) vs GPC(M-S)

Environmental Benefits of Geopolymer Technology

Usage of industrial by-products in concrete imparts better value

addition to these materials.

Safe disposal of hazardous industrial by-products like fly ash.

Usage of natural recourses like limestone and clay can be

significantly reduced.

The agricultural lands can be saved from being filled up with fly

ash.

Reduction of high energy loss and water loss.

Global warming can be reduced. 70

Economic Benefits of Geopolymer Technology

Reduction upto 10-30 % in the cost of fly ash based geopolymer

concrete.

Savings in cost of expensive moulds at precast element industries.

Savings in time as the geopolymer concrete attains its full

strength in one day.

It is possible to increase the construction rate more faster by

implementing geopolymer technology.

Water curing is completed eradicated in the geopolymer concrete

results in saving the cost of water. 71

Conclusions Low-calcium fly ash-based geopolymer concrete has an excellent

compressive strength and is suitable for structural applications.

The Geopolymer concrete can be used as an appropriate alternative to

OPC Concrete.

72