Geopolymer concrete is a type of concrete that is made by reacting aluminate and silicate bearing materials with a caustic activator. Commonly, waste materials such as fly ash or slag from iron and metal production are used, which helps lead to a cleaner environment. Since, the current usage of fly ash in India is still around 25% and below 45% even in the developed countries like United States, there is a huge scope for fly ash in upcoming years. So let us harness a billion dollar resource that has been wasted so far.

1. BY
P.UDAY KIRAN (16261A0136)
UNDER THE GUIDANCE OF
Mr.A.Abhilash
Assistant professor
DEPARTMENT OF CIVIL ENGINEERING
MAHATMA GANDHI INSTITUTE OF TECHNOLOGY
(Affiliated to Jawaharlal Nehru Technological University, Hyderabad)
Approved by AICTE, New Delhi
Sponsored by Chaitanya Bharathi Educational Society
Gandipet, Hyderabad – 500 075
www.mgit.ac.in
A Study on strength and sorptivity of
geopolymer concrete

2. Objectives:
• To reduce CO2 emission and produce eco-friendly concrete.
• To achieve a high strength concrete compared with conventional
concrete.
• To achieve a new type of concrete which is flexible in nature.
• The water absorption and sorptivity properties of fly-ash based
geopolymer concrete were studied in detail.

3. Methodology:
• The main difference between geopolymer concrete (GPC) and
Ordinary Portland Cement (OPC) concrete is the binder which binds
the aggregates together and imparts strength to concrete
• e. In OPC , cement acts as the binder whereas in GPC , the silicates
and hydroxides of sodium or potassium in the presence of alkaline
activator solutions act as binders.
• First, the fine aggregate, coarse aggregate, GGBS and fly ash is mixed
in dry condition for 3- 4 minutes and then the alkaline solution which
is a combination of Sodium hydroxide solution and Sodium silicate
solution and super plasticizer is added to the dry mix.
• The mixing is done about 6-8 minutes for proper bonding of all the
materials.
• After the mixing, the specimens are casted by giving proper
compaction in three layers.

4. • The alkaline liquid/binder ratio between 0.35 and 0.55 for fly ash
based geopolymer.
• The following parameters were considered to arrive at the quantities
of the constituent materials.
a. Alkaline liquid to binder ratio : 0.5
b. Ratio of Na2SiO3/NaOH : 2
d. Molarity of NaOH solution : 10M,12M,14M
f. Curing Temperature : 60°C
g. Curing Mode : Ambient and Steam curing
• The sorptivity test is a simple and rapid test to determine the
tendency of concrete to absorb water by capillary suction. The test
was developed by Hall (1981) and is based on Darcy’s law of
unsaturated flow.

5. • Concentration of Sodium hydroxide in terms of molarity: 10M,12M,14M
• Concentration of Sodium silicate solution: 50.32 % solid content
• Solution-to-fly ash ratio by mass: 0.5
• Sodium silicate-to-sodium hydroxide ratio by mass: 2.0
• Fine aggregate
(a) Type: M sand
(b) Water absorption: 3.67 %
(c) Water content: Nil
• Coarse aggregate
(a) Type: Crushed/angular
(b) Maximum size: 20 mm
(c) Water absorption: 0.89 %
(d) Moisture content: Nil.

6. Oxide composisition (%by
mass)
flyash
Sio2 59.2
Al2O3 38.02
CaO 0.94
MgO 0.28
Na2O3 0.47
K2O 0.22
Loss of ignistion 1.05
Properties of FLYASH:
Sl no Characteristics GGBS (% wt.)
1 Aluminium oxide 7-12
2 Calcium oxide 34-43
3 Sulphur 1.0-1.9
4 Magnesium oxide 0.15-0.76
5 Silica 27-38
6 Manganese oxide 7-15
7 Iron oxide 0.2-1.6
Properties of GGBS:

7. Property
Coarse
Aggregate
20mm
Fineness Modulus 8.14
Specific gravity 2.87
Bulk Density
1533.33
kg/m3
Percentage of voids 45.24%
Properties Manufactured sand
Specific gravity 2.622
Bulking (%) 19.26
Fineness 2.91
Properties of Coarse Aggregate: Properties of artificial sand:

8. Specific gravity of fly ash :
Specific gravity of NaoH=1.24
Specific gravity of Na2Sio3=1.14

9. TRIAL AND ERROR METHOD
• We are done with the 2 trials on GPC , as we changed the proportions
of flyash and ggbs
I. Fly ash and ggbs as 70% and 30% of total fines
II. Fly ash and ggbs as 80% and 20% of total fines
• These trials we were done for GPC of molarity 10 (i.e.10M).

10. Mix design:
• As per literatures we fix the values of quantity of total fines and some
mentioned above
• For 25-40 Mpa we have select the quantity of fines in between 370-
390 kg/m*3
• For aggregate proportions we considered density of concrete
• Density of concrete 2400 kg/m*3
• We are assuming the aggregate quantity as 70% of total volume of
concrete
• Considering the ratio Fine aggregate : coarse aggregate as 60:40

11. • Total aggregate quantity =0.7*2400=1680 kg/m*3
I. Fine aggregate quantity = 0.4*1680=672 kg/m*3
II. Coarse aggregate quantity =0.6*1680=1008 kg/m*3
Mix Design for 10M of GPC :
Total volume = 0.08 m*3
Total fine quantity = 29.6 kg (as we considering 380kg per 1m*3)
In that 1.fly ash = 20.72kg (70%)
2.ggbs = 8.96kg (30%)
Alkaline to total fines ratio = 0.5
Alkaline content = 0.5*29.6 = 14.8kg
That to we have add :
Sodium hydroxide (NaoH) Solution = 3.97 lit
Sodium silicate solution = 7.04 lit
Coarse aggregate = 80.64 kg
Fine aggregate ( M sand ) = 53.76 kg

13. • Super plastisizer = 1% of total fines = 29.6 kg *1 %
= 250.84 ml
Results :
1. Compressive strength of cube 1 =45.2mpa
2. Compressive strength of cube 2 =44.6mpa
3. Compressive strength of cube 3 =45.4mpa

14. Mix Design for 10M,12M,14M of GPC(For compressive strength) :
Total volume = 0.036 m*3
Total fine quantity = 13.32 kg (as we considering 380kg per 1m*3)
In that 1.fly ash = 10.656 kg (80%)
2.ggbs = 2.664 kg (20%)
Alkaline to total fines ratio = 0.5
Alkaline content = 0.5*13.32 = 6.66 kg
That to we have add :
Sodium hydroxide (NaoH) Solution = 1.79 lit
Sodium silicate solution = 3.17 lit
Coarse aggregate = 36.28 kg
Fine aggregate ( M sand ) = 24.19 kg
Super plasticizer = 1% = 112.88 ml
Extra water added =150ml

15. Mix Design for 10M,12M,14M(For Split tensile strength):
Total volume = 0.026 m*3
Total fine quantity = 9.62 kg (as we considering 380kg per
1m*3)
In that 1.fly ash = 7.696 kg (80%)
2.ggbs = 1.924 kg (20%)
Alkaline to total fines ratio = 0.5
Alkaline content = 0.5*9.62 = 4.81 kg
That to we have add :
Sodium hydroxide (NaoH) Solution = 1.335 lit
Sodium silicate solution = 2.29 lit
Coarse aggregate = 26.208 kg
Fine aggregate ( M sand ) = 17.472 kg
Super plasticizer 1% = 81.525 ml
Extra water added =120ml

16. Mix Design for 10M,12M,14M(For Flexural strength):
Total volume = 0.024 m*3
Total fine quantity = 8.88 kg (as we considering 380kg per 1m*3)
In that 1.fly ash = 7.104 kg (80%)
2.ggbs = 1.776 kg (20%)
Alkaline to total fines ratio = 0.5
Alkaline content = 0.5*8.88 = 4.44 kg
That to we have add :
Sodium hydroxide (NaoH) Solution = 1.19 lit
Sodium silicate solution = 2.114 lit
Coarse aggregate = 24.192 kg
Fine aggregate ( M sand ) = 16.128 kg
Super plasticizer 1% = 75.25 ml
Extra water added =120ml

17. Required Molarity Weight in g. of Sodium
hydroxide flakes
10M
400
12M 480
14M 560
Weights of NaOH flakes:

18. Compressive strength test results at 7 days
specimen
compressive
strength
N/mm2
Avg.compressive
strength N/mm2
10M
sample 1 33.30
31.883
sample 2 30.38
sample 3 31.97
12M
sample 1 39
39.34
sample 2 40.54
sample 3 38.48
14M
sample 1 29.22
31.71
sample 2 34.08
sample 3 31.85
Compressive Strength Test Results at 7 Days
For Cube 150mm X 150mm X 150mm:

19. Compressive strength test results at 7 days
specimen
compressive
strength
N/mm2
Avg.compressive
strength N/mm2
10M
sample 1 32
32.5
sample 2 32.6
sample 3 33
12M
sample 1 40.2
41.6
sample 2 43
sample 3 43.8
14M
sample 1 41
39.93
sample 2 39.6
sample 3 39.2
Compressive Strength Test Results at 28 Days
For Cube 150mm X 150mm X 150mm:

20. Split tensile Strength Test Results at 7 Days For
Cylinder 150mm × 300mm :
Split tensile Strength Test Results at 7 Days
specimen
Split tensile
Strength
N/mm2
Avg. Split tensile
Strength
N/mm2
10M
sample 1 9.47
9.18
sample 2 8.89
12M
sample 1 12.56
10.83
sample 2 9.10
14M
sample 1 11.87
10.825
sample 2 9.78

21. Flexural Strength Test Results at 7 Days For
Beam 100mm × 100mm ×500mm :
Flexural Strength Test Results at 7 Days
specimen
Flexural Strength
N/mm2
Avg. Flexural Strength
N/mm2
10M
sample 1 2.88
2.71
sample 2 2.54
12M
sample 1 4.10
3.995
sample 2 3.89
14M
sample 1 3.10
3.025
sample 2 2.95

22. 10M 12M 14M
Conventional concrete 24.5 24.5 24.5
Geopolymer concrete 31.883 39.34 31.71
24.5 24.5 24.5
31.883
39.34
31.71
0
5
10
15
20
25
30
35
40
45
50
Avg.compressive
strength
N/mm2
Molarity
Compressive Strength Test Results at 7 Days
Conventional concrete Geopolymer concrete

23. 10M 12M 14M
Conventional concrete 33 33 33
Geopolymer concrete 32.5 41.6 39.93
33 33 33
32.5
41.6
39.93
0
5
10
15
20
25
30
35
40
45
50
Avg.compressive
strength
N/mm2
Molarity
Compressive Strength Test Results at 28 Days
Conventional concrete Geopolymer concrete

24. 10M 12M 14M
Conventional concrete 2.67 2.67 2.67
Geopolymer concrete 9.18 10.83 10.825
2.67 2.67 2.67
9.18
10.83 10.825
-1
1
3
5
7
9
11
13
15
Molarity
Split tensile Strength Test Results at 7 Days
Conventional concrete Geopolymer concrete

25. 10M 12M 14M
Conventional concrete 3.02 3.02 3.02
Geopolymer concrete 2.71 3.995 3.025
3.02 3.02 3.02
2.71
3.995
3.025
0
1
2
3
4
5
6
7
8
9
10
Molarity
Flexural Strength Test Results at 7 Days
Conventional concrete Geopolymer concrete
Avg. Flexural Strength
N/mm2

28. Action plan:
February 4th - sample mix with 10M alkaline activator and casting of
specimen.
February 12th - sample mix with 12M alkaline activator and casting of
specimen.
February 19th - sample mix with 14M alkaline
activator and casting of specimen.
February 11th - 7 days strength for 10M activator.
February 19th -7 days strength for 12M activator.
February 26th - 7 days strength for 14M activator.
March 5th - 28 days strength for 10M activator.
March 12th - 28 days strength for 12M activator.
March 19th - 28 days strength for 14M activator.
March 20th -Sorptivity test
March 29th -Submission of final report

29. References:
• 1. Davidovits J (1995) Global warming impact on the cement and aggregate
industries. World
• Res Rev 6(2):263–278
• 2. Hardjito D, Wallah SE, Sumjouw DMJ, Rangan BV (2004) On the
development of fly ash
• based geopolymer concrete. ACI Mater J 101:467–472
• 3. Mullick AK (2005) Use of fly ash in structural concrete: part I—why?
Indian Conc J 79:13–22
• 4. Kumar V, Mathur M, Sinha SS, Dhatrak S (2005) Fly Ash: an
environmental savior. Fly Ash
• Utilisation Programme (FAUP), TIFAC, DST, Fly Ash India, New Delhi, IV, pp
1.1–1.4
• 5. Malhotra VM, Ramezanianpour AA (1994) Fly Ash in concrete. Canada
Centre for Mineral

30. References:
• 6. Malhotra VM (1999) Making concrete greener with fly ash. ACI Conc Int 21(5):61–66
• 7. Davidovits J (1991) Geopolymers: inorganic polymeric new materials. J Therm Anal
• 37:1633–1656
• 8. Davidovits J (1994) Geopolymers: man-made geosynthesis and the resulting development of
• very early high strength cement. J Mater Edu 16(2, 3):91–139
• 9. Davidovits J (1988) Geopolymer chemistry and properties. In: Proceedings of 1st European
• conference on soft mineralurgy. Geopolymere, vol 88, France, pp 25–48
• 10. Rangan BV (2008) Mix design and production of fly ash based geopolymer concrete. Indian
• Concr J 82:7–15
• 11. Anuradha R, Sreevidya V, Venkatasubramani R, Rangan BV (2012) Modified guidelines for
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• (3):353–364
• 12. Patankar SV, Jamkar SS, Ghugal YM (2012) Effect of sodium hydroxide on flow and strength
• of fly ash based geopolymer mortar. J Struct Eng 39(1):7–12
• 13. Jamkar SS, Ghugal YM, Patankar SV (2013) Effect of fineness of fly ash on flow and
• compressive strength of geopolymer concrete. Indian Concr J 87(4):57–61