Ternary/Triple Blending Concrete(GGBFS + FA + OPC)

Hume Concrete Sdn. Bhd.

Introduction

• Ternary/Triple blending refers to blending of Ordinary Portland Cement (OPC) with two supplementary cementitious material (SCM).

• 3 common SCM used widely in the industries are Fly Ash (FA), Ground Granulated Blast Furnace Slag (GGBFS) and Silica Fume (SF)

• This presentation is focusing on the ternary blending of OPC with GGBFS and FA

• It is not common to find research paper focusing on ternary mixing of OPC, GGBFS and FA, however; a successful attempt had been achieved to compare a few research paper, in terms of performance for this kind of concrete mixing.

Comparison Data

Source Mixture Number

Concrete Grade OPC (%) GGBFS (%) FA (%) Slump (mm) W/CM

1 1 80PC4S16F59 80 4 16 n.d 0.59

2 80PC8S12F59 80 8 12 n.d 0.59

3 80PC12S8F59 80 12 8 n.d 0.59

4 80PC16S4F59 80 16 4 n.d 0.59

5 100PC59 100 - - n.d 0.59

2 1 80PC4S16F33 80 4 16 0.33

2 80PC8S12F33 80 8 12 0.33

3 80PC12S8F33 80 12 8 0.33

4 80PC16S4F33 80 16 4 0.33

100PC33 100 - - 0.33

3 1 50PC25FS38 50 25 25 160 0.38

2 50PC25FS60 50 25 25 140 0.60

3 100PC38 100 - - 80 0.38

4 100PC60 100 - - 90 0.60

4 1 65PC25S10F42 65 25 10 60 – 100 0.42

2 100PC 100 - - 60 – 100 0.42

Source Mixture Number

Concrete Grade OPC (%) GGBFS (%) FA (%) Slump (mm) W/CM

5 1 50PC30S20F34 50 30 20 595 0.34

2 100PC34 100 - - 590 0.34

6 1 50PC18S36Fc44 50 18 36 650 0.44

2 50PC18S36Ff44 50 18 36 650 0.44

3 100PC44 100 - - 650 0.44

Indicator:S = SlagF = Fly AshPC = Portland CementFS = Fly Ash together with Slag; Example: 25FS = 25% FA, 25% S

Compressive Strength Result

Source Mixture Number Concrete Grade Compressive Strength (MPa)

7 Days 28 Days 90 Days

1 1 80PC4S16F59 - 23.23 -

2 80PC8S12F59 - 27.16 -

3 80PC12S8F59 - 24.70 -

4 80PC16S4F59 - 29.72 -

5 100PC59 - 30.13 -

2 1 80PC4S16F33 40.90 65.95 -

2 80PC8S12F33 42.74 65.12 -

3 80PC12S8F33 43.79 68.55 -

4 80PC16S4F33 52.52 72.39 -

5 100PC33 43.90 65.14 -

3 1 50PC25FS38 - 83.10 86.60

2 50PC25FS60 - 42.90 51.20

3 100PC38 - 86.10 92.20

4 100PC60 - 55.70 57.50

4 1 65PC25S10F42 33.50 43.30

2 100PC42 29.40 37.70

Source Mixture Number Concrete Grade Compressive Strength (MPa)

7 Days 28 Days 90 Days

5 1 50PC30S20F34 24.30 41.71 -

2 100PC34 35.53 43.35 -

6 1 50PC18S36Fc44 38.90 50.00 -

2 50PC18S36Ff44 18.80 35.80 -

3 100PC44 39.00 43.80 -

Indicator:S = SlagF = Fly AshPC = Portland CementFS = Fly Ash together with Slag; Example: 25FS = 25% FA, 25% S

0102030405060708090

100

Compressive Strength (MPa) Comparison

Discussion (Compressive Strength)• According to Neville (2008), strength of cement increases when ratio of water to

cement (w/c) decreases. For concrete, the relation still applies, although ratio of GGBS and fly ash (FA) plays some important role in terms of strength of the concrete.

• From source 1, we can conclude that at higher w/c ratio (0.59), ternary mixtures tends to have lower strength compared to pure portland cement (PC)

• From source 2, however at lower w/c ratio (0.33), ternary mixture tends to have better strength gain compared to pure PC, where much better strength is gained when ratio of GGBS is higher than FA (16% GGBS, 4% FA)

• Highest strength is gained when using w/c ratio of 0.38 (Accordingly to Neville, 2008), however, there will be a slight drop of strength of ternary mixture compared to pure PC, given an even ratio of both GGBS and FA in ternary mixture.

• Hence, it could be theorized that the best strength gained will be ternary mixture at w/c ratio of 0.38, with ratio of GGBS being higher compared to FA. In addition, higher amount of PC might contribute to the increase of strength gained, compared to mixtures that are using less PC in mixtures.

Split Tensile Strength Result

Source Mixture Number Concrete Grade Split Tensile Strength (MPa)

7 Days 28 Days

1 1 80PC4S16F59 - 2.08

2 80PC8S12F59 - 2.98

3 80PC12S8F59 - 3.00

4 80PC16S4F59 - 3.23

5 100PC59 - 3.24

2 1 80PC4S16F33 4.53 5.36

2 80PC8S12F33 4.24 5.27

3 80PC12S8F33 4.09 4.94

4 80PC16S4F33 3.41 4.65

5 100PC33 3.21 3.78

3 1 50PC25FS38 - -

2 50PC25FS60 - -

3 100PC38 - -

4 100PC60 - -

4 1 65PC25S10F42 - -

2 100PC - -

Source Mixture Number Concrete Grade Split Tensile Strength (MPa)

7 Days 28 Days

5 1 50PC30S20F34 2.19 2.91

2 100PC34 2.46 2.96

6 1 50PC18S36Fc44 - -

2 50PC18S36Ff44 - -

3 100PC44 - -

Indicator:S = SlagF = Fly AshPC = Portland CementFS = Fly Ash together with Slag; Example: 25FS = 25% FA, 25% S

80PC4S16F5

9

80PC8S12F5

9

80PC12S8F5

9

80PC16S4F5

9

100PC59

80PC4S16F3

3

80PC8S12F3

3

80PC12S8F3

3

80PC16S4F3

3

100PC33

50PC30S20F3

4

100PC340

1

2

3

4

5

6

Split Tensile Strength (MPa)

Discussion (Split Tensile Strength)• There is fewer data available for comparison between the mixtures

for split tensile strength (STS), however, the explanation would be the same with discussion about compressive strength.

• Source 2 are using w/c of 0.33, while source 5 are using w/c of 0.34, which theoretically leads to a better strength for source 5’s mixture, but it is not. The are several explanation for this question.

• First, w/c ratio is not much in difference, hence there should be another reasons why.

• Second, by referring to source 2, higher ratio of GGBS leads to lower STS, which in source 5, the amount of GGBS is even higher, which could cause the even lower value of STS.

• Another reason for the result is because the amount of aggregate used compared to amount of cementitious material (CM) used.

Chloride Ion Permeability Result

Sources Mixture Number Concrete Grade Chloride Ion permeability (Coulombs)

28 Days 90 Days

3 1 50PC25FS38 387 217

2 50PC25FS60 660 376

3 100PC38 1877 1780

4 100PC60 6813 5500

6 1 50PC18S36Fc44 1326 942

2 50PC18S36Ff44 4204 660

3 100PC44 5635 5058

Indicator:S = SlagF = Fly AshPC = Portland CementFS = Fly Ash together with Slag; Example: 25FS = 25% FA, 25% S

50PC25FS38

50PC25FS60

100PC38

100PC60

50PC18S36Fc

44

50PC18S36Ff4

4

100PC440

1000

2000

3000

4000

5000

6000

7000

8000

Chloride Ion Permeability (Coulomb)

28 Days90 Days

Discussion (Chloride Ion Permeability)

• According to Sengul and Tasdemir (2009), to attain a durable concrete mixture low chloride permeability should be obtained.

• From the graph, it is clearly seen that ternary concrete is much better at resisting chloride ion, compared to ordinary concrete.

• Even though the rapid chloride ion penetration test (RCPT) value of the PC concrete is reduced about 70% by lowering the water/cement ratio, the values for the PC concrete at w/c 0.38 ratio are still 2 times or even higher than those of the ternary concrete at 0.60 w/c ratio. This result indicates that to reduce the chloride permeability of portland cement concrete, inclusion of supplementary cementitious material (SCM) are more effective than reducing the water/cement ratio.

• The presence of reaction from GGBS and FA creates a denser microstructure, reducing micro pores and clogging pores which results in lower chloride ion transport. Also, reducing amount of water, will also reduce the amount of pores, which responsible for the transport of chloride ion.

Conclusion

• From data gathered and analyzed, it can be concluded that the best combination and ratio of PC, GGBS and FA is as follow:– Lower w/c ratio, which apparently best at 0.38– Moderate ratio of cement, which is around 50 –

80%• Ratio of GGBS to FA should be equal or higher.

(According to compressive strength data)• Ratio of GGBS to FA should be higher ( STS, for w/c >

0.38)• Ratio of GGBS to FA should be lower (STS, for w/c <

0.38)

– Some mixture ratio proposed:• 80PC16S4F38, 50PC30S20F38

Thank you!