Paver Blocksby using fly ash and GGBS (Geopolymer Concrete)

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Paver Blocksby using fly ash and GGBS (Geopolymer Concrete)

P. Malliga Assistant Professor Dept of CIVIL-E.G.S

J. Ashthava Moorthy

Dept of CIVIL-E.G.S

M. Hiran

Dept of CIVIL-E.G.S

Abstract:- The living planet earth has encountered global warming due to various issues. One of the main reasons is construction industries since the foremost component of concrete is cement, which has its own environmental problems. The cement industry is one of the prime producers of carbon-di-oxide. It is estimated that about 7% of greenhouse i.e. Carbon-di-oxide gas is being emitted into atmosphere on account of production of OPC alone at global level. On other hand disposal of solid waste is a major problem. Coal power plants produce solid waste called fly ash whose disposal is difficult. Therefore urgent changes are required relating to emissions, production and application of sustainable and eco-friendly materials. This led to concept of geo polymer concrete by which cement can be entirely avoided in the concrete. This paper aims to develop geo-polymer paver blocks. The paver blocks developed are tested for their compressive, split tensile, flexural and abrasive strength as per Indian Standards 15658:2006

Need for the study:

  • To find Alternate material for cement to Control and reduce the global warming from the emission of carbon dioxide during cement production.

  • To Preserve natural resources by replacing river sand by M-sand

  • To minimize the dumping of waste material into ground .

  • To reduce the environmental problems by replacing industrial by-products into useful construction materials.

INTRODUCTION

Paver block has been used in construction for about thousands of years. Paver block is nothing but an unreinforced solid block appropriate for outdoor applications. The first concrete pavers were shaped just like a brick, 4 × 8 (10cm × 20cm) and they were called Holland Stones. These units turned out to be cheap to produce and were exceptionally strong. In addition to being economical, interlocking concrete pavers are also broadly obtainable in water-permeable designs, which have additional ecological benefits. These paver blocks allowed water to drain through their interlocks and prevent soil

erosion or increase wter level in the neighboring land area. Production of ordinary Portland cement had resulted in emission of greenhouse gas i.e. Carbon-di-oxide. As of 2010 the world production of OPC was 3300 million tons annually. This accounts for 5% of man-made emission of carbon-di-oxide at global level. On other hand clearance of solid waste is a major problem. Coal power plants produce solid waste called fly ash whose disposal is difficult. As the intricacy of environmental issues and solid waste management increases day by day it has become essential to develop sustainable and eco-friendly materials. This led us to develop geo polymer paver blocks for medium traffic with thickness of 80 mm. paver blocks were produced and tested for their properties. Geo polymers involves the activation of fly ash by alkaline solution which does not require water for curing.

MATERIALS USED:

The material used in the experimental work namely,

Cement

a substance made of burned lime, clay, sand and water to make mortar or sand, water and gravel to make concrete. FLYASH

Fly ash is extracted from pulverized or crushed coal by suitable process such as by cyclone separation or electrostatic precipitation. Fly ash collected at later stages of electrostatic precipitator is finer than the fly ash collected at initial stages of electrostatic precipitator.

GGBS

Ground-granulated blast-furnace slag (GGBS or GGBFS) is obtained by quenching molten iron slag (a by-product of iron and steel-making) from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder.

FINE AGGREGATE

Aggregate is the granular material used to produce concrete or mortar and when the particles of the granular material are so fine that they pass through a 4.75mm sieve, it is called fine aggregate.

M- SAND

Manufactured sand (M-Sand) is a substitute of river sand for concrete construction. Manufactured sandis produced from hard granite stone by crushing. The crushed sand is of cubical shape with grounded edges,

washed and graded to as a construction material. The size of manufactured sand (M-Sand) is less than 4.75mm

COARSE AGGREGATE[10 mm]

Coarse aggregates are any particles greater than 0.19 inch, but generally range between 3/8 and 1.5 inches in diameter. Gravels constitute the majority of coarse aggregate used in concrete with crushed stone making up most of the remainder.

POTABLE WATER

Potable water used for mixing and curing is clean and free from injurious amount of oils, acids, alkalis, salts, sugar, organic material or other substances that may be deleterious to concrete. Portable water is used for mixing concrete. The pH value of water lies between 6 and 8 that indicate the water is free from organic matters.

CHEMICAL COMPOSITION OF FLY ASH

S.No.

. Oxides

Require ments as per IS 3812-200

3

(% by Mass)

Test result

(% by Mass)

1.

SiO2+Al2 O3+Fe2O 3

Total > 70.0

88.86

2.

CaO

<50

0.5

3.

SiO2

> 35.0

53.66

4.

MgO

< 50

2.89

5.

SO3

< 50

0.35

6.

Na2O

0.36

7.

Loss of ignition including moisture

< 7.0

1.02

CHEMICAL COMPOSITION OF GGBS

4.

Sulphide Sulphur

< 2.0

0.5

5.

Sulphite Content

< 2.5

0.4

6.

Glass content

> 67.0

93

7.

Moisture

< 1.0

0.1

8.

Chloride content

< 0.1

0.008

9.

Manganese

< 2.0

0.11

10

.

Chemical Moduli CaO+MgO

+SiO2

CaO+MgO/ SiO2

CaO/SiO2

> 66.66

> 1.0

< 1.4

77.46

1.37

1.13

Alkaline activator solution

Alkaline activation is a chemical process in which a powdery aluminosilicate such as a fly ash is mixed with an alkaline activator to produce a paste capable of setting and hardening within a reasonably short period of time.

Material

7days

Compressive Strengt h N/mm2

14 Days

Compressivestrength N/mm2

G40

27.3

35.5

M40

27

34

HYDRATION:

It is the series of irreversible exothermic chemical reaction between cement and water.

POLYMERIZATION:

A chemical process that coines several monomers to form a polymer or polymeric compound.

ACTIVATOR SOLUTION

S. N

o.

Characteri stics

Requirements as per

BS:6699(%by

Mass)

Test result(%by Mass)

1.

Loss on ignition

< 3.0

0.29

2.

Insoluble Residue

< 1.5

0.4

3.

Magnesia Content

< 14.0

7.86

S. N

o.

Characteri stics

Requirements as per

BS:6699(%by

Mass)

Test result(%by Mass)

1.

Loss on ignition

< 3.0

0.29

2.

Insoluble Residue

< 1.5

0.4

3.

Magnesia Content

< 14.0

7.86

Molarity – 8

Ratio – 1(Sodium Hydroxide) : 2.5(Sodium Silicate) Mixing for 5 liter of water:

Sodium hydroxide – 640 ml Sodium silicate – 970 ml

Speci men No.

Size in mm

Initial weigh t W1in kg

Weig ht after abrasi on W2

in kg

Densi ty in kg/m 3

Loss in Volu me

in m3

=

Weig ht loss

/Dens ity

Loss in Thick ness in mm

1.

71 x

71 x 60

0.861

0.815

2846

1.616

x 10-5

3.2

2.

71 x

71 x 60

0.857

0.812

2831

1.589

x 10-5

3.15

3.

71 x

71 x 60

0.872

0.825

2855

1.646

x 10-5

3.27

4.

71 x

71 x 60

0.862

0.818

2847

1.545

x 10-5

3.06

Average

1.599

x 10-5

3.17

Speci men No.

Size in mm

Initial weigh t W1in kg

Weig ht after abrasi on W2

in kg

Densi ty in kg/m 3

Loss in Volu me

in m3

=

Weig ht loss

/Dens ity

Loss in Thick ness in mm

1.

71 x

71 x 60

0.861

0.815

2846

1.616

x 10-5

3.2

2.

71 x

71 x 60

0.857

0.812

2831

1.589

x 10-5

3.15

3.

71 x

71 x 60

0.872

0.825

2855

1.646

x 10-5

3.27

4.

71 x

71 x 60

0.862

0.818

2847

1.545

x 10-5

3.06

Average

1.599

x 10-5

3.17

FINENESS TEST :

the fineness of cement is 4% the fineness of flyash is 6.4% the fineness of GGBS is 6%

FLOW TABLE TEST :

Spread Diameter=24.3+22.3+26.3=72.9/3

=24.3 cm

24.3cm

Workability of our concrete mix is

COMPRESSIVE STRENGTH TEST:

COMPRESSIVESTRENGTH

LIGHT LOADING

40

30

20

10

0

40

30

20

10

0

7days

14days

7days

14days

Compressive Strength Compressive Strength

N/mm2 N/mm2

G40 M40

Compressive Strength Compressive Strength

N/mm2 N/mm2

G40 M40

ABRASION TEST:

The abrasion wear test was conducted as per the procedure given in IS 15658: 2006 and the loss involume and thickness of the specimens were calculated. The average loss in thickness is 3.17mm which is less than the limiting maximum value of 3.5 mm prescribed for general purpose paver blocks. Hence the paver blocks can be used for general purpose applications.

HEAVY LOADING

CONCLUSION

  • The maximum compressive strength of 35.5 Mpa , is achieved at 30:70 replacement of FLYASH and GGBS respectively as compare to 34 Mpa of strength of conventional concrete for 14 days curing in potable water. Thus maximum strength is achieved in 70 % of GGBS replacement than other replacement levels.

  • Using FLYASH and GGBS instead of cement not only provides the economy in the construction but it also facilitates environmental friendly disposal of the waste slag which is generated in huge quantities from the steel industries.

  • Ambient curing of geopolymer concrete will give better results. So thereby, saving potable water.

  • Hopefully one day in the future GEOPOLYMER CONRETE PAVER BLOCK will replace CONVENTIONAL CONCRETE as the most abundant man-made material in construction field.

REFERENCES

  1. Ling, T. C., Nor, H. M., Hainin, M. R., and Lim, S. K., Long Term Strength of Rubberized Concrete Paving Blocks, ICE Construction Materials Conference, 2010,19-26.

  2. Aaron Darius Vaz., Donal Nixon DSouza., NoothanKaliveer.,Satish, K. T., Amar, S. M., Geopolymer Paver

    Blocks ,International Conference on Advances in Civil Engineering, 2012.

  3. Basil Mali, M. and Renjan Abraham., Study on geopolymer concrete used for paving blocks, International Journal of Innovative Research in Advanced Engineering, 3 (9), 2016, 62-66.

  4. Navya,G and Venkateeswara Rao.J, Influence of Polyester fibre on Concrete Paver Blocks, IOSR Journal of Mechanical and Civil Engineering (IOSR- JMCE), 11(4), 2014, 70-75.

  5. [5]Banupriya, C., Sharon John, Suresh, R., Divya, E., Vinitha, D., Experimental investigations on geopolymer bricks / paver blocks, Indian Journal of Science and Technology, 9 (16), 2016.

  6. [6]Vijai, K., Kumutha, R., Vishnuram, B. G., Effect of types of curing on strength of geopolymer concrete, International Journal of Physical Sciences, 5(9), 2010,1419-1423

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