geopolymer concrete

International Conference on Transportation & Civil EngineeringMarch 21-22, 2015

at London

Swapnil P WanjariAsst. Professor, VNIT, Nagpur, IN

Jerril SebastianM.Tech Scholar, VNIT, Nagpur, IN

Visvesvaraya National Institute of Technology, Nagpur, India

Partial replacement of Cement in the Geopolymer Quarry Rock Dust Concrete under different Curing Conditions

Contents

•Challenges & Opportunities in the world of Concrete•Objectives of Present work• Introduction•Experimental Investigation•Results and discussion•Conclusion and recommendation•Future Scope

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Challenges & opportunities

Challenges :

• Concrete is mostly used construction material

• The need for concrete is increasing day by day to meet infrastructure needs of the country

• Since, cement is the basic binding material being used in concrete, the production of cement is also increasing day by day

• Production of cement consumes lot of energy, natural resources & also emits almost an equal amount of carbon dioxide into the atmosphere

• This is creating a challenging situation in the world of Concrete14-04-2015 3

Advantages Of Addition Of Crusher Dust In Geopolymer Concrete

•The availability of natural sand is scarce and Costly thus crusher dust can be used as a replacement to natural sand

•The extraction of natural sand is a major environmental concern so when crusher dust is used, the burden on the environment is lessened

•The disposal of crusher dust is also a major environmental concern as it causes many respiratory diseases14-04-2015 4

Geopolymers• In 1978, Davidovits proposed that an alkaline liquid could be

used to react with the silicon (Si) and the aluminium (Al) in a source material of geological origin or in by-product materials such as fly ash and rice husk ash to produce binders.

• Chemical reaction that takes place in this case is a polymerisation process, called the term ‘Geopolymer’ to represent these binders.

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Generation & Utilization of Flyash

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Alkaline Liquid

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Sodium Silicate

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Physical & Chemical Properties of fly ash

% CONTENT

Specific gravity 2.19

Silicon dioxide(sio2) 55.5

Aluminium oxide(Al203) 28.3

Ferric oxide (Fe203) 11.2

Calcium oxide (CaO) 1.18

Mangnesium oxide(MgO) 0.69

Alkalies equivalent

Titanium oxide(TiO2) 1.8

Sulphur trioxide(SO3) 0.44

Loss on ingnition 1.10

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Properties of Cement

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Sl.No Particulars Test ResultsRequirements of

IS:12262:2013

1

Setting Time (minutes)

a. Initial 187 30 Min

b. Final 255 600 Max

2

Soundness

a. Le-Chatelier’s Expansion (mm) 1.2 10.0 Max

3 Compressive Strength (MPa)

a. 72 +/- 1hr. (3 days) 30.66 23 Min (MPa)

b. 168 +/- 2hr. (7 days) 36.9 33 Min (MPa)

c. 672 +/- 4hr. (28 days) 44.93 43 Min (MPa)

Physical Properties of Aggregates

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Physical Properties of Coarse Aggregate(As per IS 383-1970)

Particulars SizeSpecific Gravity

Water Absorption

Coarse Aggregate 20 mm 2.85 0.80%

Coarse Aggregate 10mm 2.83 1%

Crusher Dust 2.65 0.84%

Combined Grading Of Aggregates

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IS Sieves 20 mm 10 mmCrusher

DustCombine Grading

Specified Grading

% 39% 26% 35% 100 U. limits L. limits

20 mm 100 100 100 100 95 100

10 mm 4.7 86.85 100 59.43 50 75

4.75 mm 1.5 8.4 98.05 37.09 30 50

2.36 mm 0 0 71.5 25.03 25 45

1.18 mm 0 0 49.8 17.43 15 35

600 µ 0 0 30.5 10.68 10 35

300 µ 0 0 17.4 6.11 3 15

150 µ 0 0 12.25 4.29 0 6

75 µ 0 0 0 0

Ingredients of the mixes

13

Ingredients UnitMix 1 Mix 2 Mix 3 Mix 4

100% FA+0%C 90% FA+10%C 70% FA+30%C 50% FA+50%C

Fly Ash Kg/m3 375 337.5 262.5 187.5

Cement (43 Grade) Kg/m3 0 37.5 112.5 187.5

10 mm aggregate Kg/m3 489 489 489 489

20 mm aggregate Kg/m3 733 733 733 733

Crusher Dust Kg/m3 650 650 650 650

Alkaline Liquids Kg/m3 153 137.7 107.1 76.5

Na2Sio3 Kg/m3 102 91.8 71.4 51

NaoH Kg/m3 51 45.9 35.7 25.5

Molarity 14 14 14 14

Super Plasticizer Kg/m3 5.6 5.6 5.6 5.6

Water Kg/m3 50 68 83 98

Curing Temperature OC 60 60 60 60

Humidity (Steam Curing) % 50 50 50 50

Rest Period Hours 24 24 24 24

Curing Period Hours 24 24 24 24

No. Of Cubes Number 30 30 30 30

No. Of Beams Number 9 9 9 9

Water-Binder Ratio 0.3 - 0.35 0.3 - 0.35 0.3 - 0.35 0.3 - 0.35

Preliminary Laboratory Work

• In the beginning, numerous trial mixtures of Geopolymer concrete were manufactured, and test specimens in the form of 100x100x100 mm cubes & 150x150x150 mm cubes were made.

The main objectives of the preliminary laboratory work were:

•To familiarize with the making of fly ash-based Geopolymer concrete;

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Casting of Concrete

Number of Specimens casted for Experimental Investigations

150x150x150mm cubes = 120 Nos

100X100X500mm Beam = 36 Nos

Total = 156

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Geopolymer Concrete

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Compression Test

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Flexural Test

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Durability Study

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Table 1: Experimental Results (Slump Test, Compressive & Flexural Strength)

20

Sr.Geopolymer Concrete Mix

Type of Curing Slump(mm)

Compressive Strength (Mpa) Flexural Strength (Mpa)

(Avg.) (Avg.)

3 Days 7 Days 28 Days 28 Days

1100 % Fly Ash + 0 %

Cement

Normal Curing

230

6.55 12.5 20.1 4

Steam Curing 23 24.9 26.8 5.5

Hot air Oven 24.5 26.3 28.1 6

290 % Fly Ash + 10 %

Cement

Normal Curing

215

7.8 15 21.9 4.2

Steam Curing 16.8 22.4 26.8 5.4

Hot air Oven 20.6 24.6 30.2 5.9

370 % Fly Ash + 30%

Cement

Normal Curing

40

12.5 20.6 29.2 5.4

Steam Curing 18.6 25.3 34.1 6.5

Hot air Oven 21.2 28.2 36.7 6.8

450 % Fly Ash + 50%Cement

Normal Curing

30

12.9 17.7 27.5 5

Steam Curing 14.2 24.2 30.3 5.6

Hot air Oven 16.1 26.5 33.9 6.2

Discussions

• The Discussion of all the investigation works have been divided into following phases

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Sr. Phase Nature of Study

1 Phase I

Comparative study of Compressive strength of Geopolymer Concrete (G 20) with replacement of different percentage of cement by fly ash under different curing conditions

2 Phase IIComparison of Compressive Strength of Geopolymer Concrete in Oven, Steam & Normal Curing conditions

3 Phase IIIComparison of Compressive Strength of Geopolymer Concrete Cubes with Increase in Cement By weight %.

4 Phase IVComparison of Flexural Strength of Geopolymer Concrete at different curing conditions

5 Phase VComparison of durability aspect such as loss in weight and compressive strength

Experimental Results

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• The Compressive strength and flexural strength of all the samples are given in table 1 respectively.

• The graphs were plotted for different combinations of fly ash and cement at different curing conditions. In this study, compressive strength and flexural strength was measured as per recommendation of IS 516:1959

• Durability study of concrete was done and carried out based on ASTM D1141.

PHASE - I

Comparative study of Compressive strength of Geopolymer Concrete (G 20) with replacement of different percentage of

cement by fly ash under different curing conditions

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Compressive Strength

100% FA+0% C

90% FA+10% C 70% FA+30% C

50% FA+50% C

Fig 1 : Comparison of Compressive Strength Of 100 % Fly Ash + 0% Cement Geopolymer (G 20) Concrete

with 150mm Cubes

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0

5

10

15

20

25

30

0 7 14 21 28 35

Co

mp

ress

ive

Str

en

th

Curing Days

100% Fly Ash + 0% Cement

Hot air Oven

Normal Curing

Steam Curing

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0

5

10

15

20

25

30

35

0 7 14 21 28 35

Co

mp

ress

ive

Str

en

th

Curing Days

90% Fly Ash + 10% Cement

Hot air Oven

Normal Curing

Steam Curing


with 150mm Cubes

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0

5

10

15

20

25

30

35

40

0 7 14 21 28 35

Co

mp

ress

ive

Str

en

th

Curing Days

70% Fly Ash + 30% CEMENT

Normal Curing

Steam Curing

Hot air Oven


with 150mm Cubes


with 150mm Cubes

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0

5

10

15

20

25

30

35

40

0 7 14 21 28 35

Co

mp

ress

ive

Str

en

th

Curing Days

50 % Fly Ash + 50%Cement

Normal Curing

Steam Curing

Hot air Oven

PHASE - II

Comparison of Compressive Strength of Geopolymer Concrete in Oven, Steam & Normal Curing conditions

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Oven Curing

Steam Curing

Normal Curing

Fig 5 : Comparison of Compressive Strength of Oven Cured Geopolymer Concrete Cubes

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0

5

10

15

20

25

30

35

40

0 7 14 21 28 35

Co

mp

ress

ive

Str

en

th

Curing Days

Oven Cured Cubes

50% FA

70% FA

90% FA

100 % FA

Fig 6 : Comparison of Compressive Strength of Steam Cured Geopolymer Concrete Cubes

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Fig 7 :Comparison of Compressive Strength of Normal Cured Geopolymer Concrete Cubes

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0

5

10

15

20

25

30

35

0 7 14 21 28 35

50 % Fly Ash (SD)

70 % Fly Ash (SD)

90 % Fly Ash (SD)

100 % Fly Ash (SD)

Normal Curing

PHASE - III

Comparison of Compressive Strength of Geopolymer Concrete Cubes with Increase in Cement By weight %.

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0% CEMENT

10% CEMENT 30% CEMENT

50% CEMENT

Fig 8 :Comparison of Compressive Strength of Geopolymer Concrete Cubes with Increase in Cement

By weight % (3 Days)

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0

5

10

15

20

25

30

0% 10% 20% 30% 40% 50% 60%

Co

mp

ress

ive

Str

en

th in

MP

a

Cement by Weight %

3 days Testing

Hot air

Normal curing

steam curing



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0

5

10

15

20

25

30

0% 10% 20% 30% 40% 50% 60%

Co

mp

ress

ive

Str

en

th in

MP

a

Cement by Weight %

7 days Testing

Hot Air Oven

Normal Curing

Steam Curing



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0

5

10

15

20

25

30

35

40

0% 10% 20% 30% 40% 50% 60%

Co

mp

ress

ive

Str

en

th in

MP

a

Cement by Weight %

28 days Testing

Hot Air Oven

Normal Curing

Steam Curing

PHASE - IV

Comparison of Flexural Strength of Geopolymer Concrete at different curing conditions

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Flexural Strength

Oven Curing

Steam Curing

Normal Curing

Fig 11 :Comparison of Flexural Strength of Geopolymer Concrete (28 Days)

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3

3.5

4

4.5

5

5.5

6

6.5

7

Normal Curing Steam Curing Hot air Oven

50 % Fly Ash (SD)

70 % Fly Ash (SD)

90 % Fly Ash (SD)

100 % Fly Ash (SD)

Flexural Strength for 28 Days

Flex

ura

l Str

engt

h

PHASE - V

Comparison of durability aspect such as loss in weight and compressive strength

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Loss of Weight

and Compressive

Strength

100% FA+0% C

90% FA+10% C 70% FA+30% C

50% FA+50% C

Table 2: Experimental Results (Durability Study)

39

The Test was carried out for 56 Days with (97% Water + 3% H2SO4)

Sl. No Mix Curing ConditionInitial Weight

(Kg) (Avg.)

Final Weight (Kg) (Avg.)

Loss In Weight (%)

1 50 % Fly Ash (SD) Hot air Oven Curing 8.294 8.0955 2.9




Fig 12 :Comparison for Loss In Weight

40

0

0.5

1

1.5

2

2.5

3

3.5

50 % Fly Ash 70 % Fly Ash 90 % Fly Ash 100 % FlyAsh

Loss

In W

eig

ht

in %

% of Flyash

Comparison for Loss In Weight

Table 3: Experimental Results (Durability Study)

41

Sl. No Mix Curing Condition

28 Days Compressive

Strength(MPa) (Avg.)

56 Days Compressive

Strength(MPa) (Avg.)

1 50 % Fly Ash (SD) Hot air Oven Curing 33.9 24.08




Fig 13 : Comparison for Loss In Compressive Strength

42

0

5

10

15

20

25

30

35

40

50 % Fly Ash 70 % Fly Ash 90 % Fly Ash 100 % Fly Ash

Co

mp

ress

ive

Str

en

gth

% of Flyash

Loss in Compressive Strength

28 Days Cured

56 Days Cured inSulphuric Acid Solution

ConclusionsBased on the results of the experimental investigation, conclusions that could be drawn are as follows

• Hot Air Curing provides highest Compressive strength in comparison with Steam and Normal curing

• Maximum Compressive strength was found in Combination of 70% FA + 30% C in all curing conditions

• Steam curing (60oC and 50% Humidity) condition could be relatively better option than the Hot air curing condition (60oC). The presence of humidity condition in the concrete reduces compressive strength

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Conclusions

• For Normal curing condition, with increase in amount of cement by weight %, Compressive strength increases.

• The Compressive strength of Geopolymer concrete was found to be increasing with replacement of fly ash by cement. It is found that replacement of 30% of fly ash by cement provides highest compressive strength.

• Hot air cured beams gives highest flexural strength in comparison with steam and normal curing.

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Conclusions

• Maximum Flexural strength was found in Combination of 70% FA + 30% C in all curing conditions

• Steam curing (60oC and 50% Humidity) condition could be relatively better option than the hot air curing (60oC) condition because flexural strength observed under steam curing condition is found to be nearer to hot air curing

• For Normal curing condition, with increase in amount of cement by weight %, Flexural strength increases.

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Conclusion

• In durability test, Loss in weight is found to be least in 100 % FA + 0% C compared to other 3 combinations. Loss in weight was found to be .7 %.

• In durability test, loss in Compressive strength is least in 100 % FA + 0% C compared to all other 3 combinations. Loss in compressive strength was found to be 16.3 %.

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Future Scope

The future scope of the present work could be as given below

• The flexural behaviour of reinforced Geopolymer concrete beams including Flexural strength, crack pattern, deflection, and ductility.

• The behaviour and strength of reinforced Geopolymer concrete slender columns subjected to axial load and bending moment.

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Future Scope

• Identifying the long properties of Geopolymer concrete likeCreep behaviour under sustained loadDrying shrinkage behaviour

• As the workability of the mixes is reducing due to the replacement of natural sand by crusher dust, further studies can be made to increase the workability by the use of admixtures

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THANK YOU

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Objectives of Present Work

To develop a mixture proportioning process to manufacture low-calcium fly ash-based Geopolymer concrete with and without OPC.

To study the properties of fresh and hardened low-calcium fly ash-based Geopolymer concrete.

To study the effect of replacing crusher dust as fine aggregate with natural sand

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Geopolymer Concrete

• “ Geopolymer concrete is a ‘new’ material that does not need the presence of Portland cement as a binder. Instead, activating the source materials such as fly ash that are rich in Silicon (Si) and Aluminium (Al) using high alkaline liquids produces the binder required to manufacture the concrete. Hence, concrete with no cement ”

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Experimental Investigation

Data for Design of Low-Calcium Fly Ash-Based Geopolymer Concrete Mixtures was taken from Rangan, 2008, 2009.

Cement of OPC 43 Grade were used in ratios of 0%, 10%, 30%,50% by weight to replace Fly ash in Geopolymer concrete.

River sand was fully replaced by crusher dust as fine aggregate.

Workability by slump method, Compressive strength of 150mm cubes, flexural strength and Durability test were determined.14-04-2015 52

Mixture Proportion

• Ratio of sodium silicate solution-to-sodium hydroxide solution, by mass is in the range of 0.4 to 2.5. This ratio was fixed at 2 for the mixtures because this ratio gives maximum strength (Reference 1, Prakash et al)

• Molarity of sodium hydroxide (NaoH) solution is in the range of 8M to16M and was fixed to 14 M as it gives maximum strength (Reference 1, Prakash et al)..

• Ratio of activator solution-to-fly ash, by mass is in the range of 0.3 and 0.4 and it was fixed to 0.4.

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Mixture Proportion Contd..

• Coarse and fine aggregates are of approximately 75% to 80% of the entire mixture by mass. This value is similar to that used in OPC concrete

• Super plasticiser, in the range of 0% to 2% of fly ash, by mass

• Extra water, when added, in mass

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