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STRENGTH AND STABILITY CHARACTERISTICS OF GGBS AND RED MUD BASED GEOPOLYMER CONCRETE INCORPORATED WITH HYBRID FIBRES

BY,ALWIS DEVA KIRUPA J.P(950012413001)

Final ME (Structures)

UNDER THE GUIDANCE OF,Mr. n. sakthieswaranAssistant professor

Regional center of anna universitythirunelveli

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AN OVERVIEWGlobal Warming – A major problem that world faces today.

Production of Portland cement – main concern in emission of pollutants (mainly CO2) in the construction industry since 1 ton equals 1 ton of CO2 emission.

Increasing the usage of industrial by-products reduce the pollution effect on environment.

Geo-polymer concrete – a best alternative since it uses up fly ash, Red mud, silica fume, rice-husk ash or GGBS for OPC.

It helps to put off Global Warming but utilizes the waste materials efficiently thereby reducing the risk of waste disposal and at same hand, safeguards dwindling natural resources.

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OBJECTIVE

To check out the viable combination ratio of Red Mud and GGBS as binder in Geopolymer Concrete (GPC).

To locate the performance of hybrid combination of fibres (metallic + non-metallic + natural) in GPC for high-performance.

To investigate the compressive strength and flexural strength of GPC specimens by casting cube & prism specimens.

To examine the durability aspects with the help of Saturated water absorption Test, Acid attack Test, Sulphate attack Test, Alkalinity Test and Carbonation depth Test .

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GEO-POLYMER CONCRETE

Geopolymer – coined by a French Professor Davidovits in 1978 to represent a broad range of materials characterized by networks of inorganic molecules.

Geopolymers - chains or networks of mineral molecules linked with co-valent bonds produced by a polymeric reaction of alkaline liquids (sodium silicate & sodium hydroxide or Potassium silicate or potassium hydroxide) with source material of geological origin or by-product material.

The chemical reaction may comprise the following steps

Dissolution of Si and Al atoms through the hydroxide action. Transportation of precursor ions into monomers. Setting or polymerization of monomers into polymeric structures.

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LITERATURE SURVEYSl No Author &

YearJournal Description

1 V. Supraja et al; 2010

International Journal of Electronics, Communication & Soft Computing Science and Engineering

Portland cement is fully replaced with GGBS.It is observed that compressive strength increased with the increase in the molarity of sodium hydroxide(9M).Compared to hot air oven curing and curing by direct sun light, oven cured specimens gives higher compressive strength.

2 Abishek H N et al;

September 2012

International Journal of Emerging Trends in Engineering and Development

Geopolymerisation is carried out in the mixture of Red mud, Fly Ash, Micro silica & water.Best results are expected in the ratio 10:80:10 adding 120 lts of water.Ultimate load carrying capacity & stiffness of beam reduces when 30% of red mud is added in the mix.From above results it is concluded that red mud can be added upto 30%.

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LITERATURE SURVEY (Contd…..)Sl No Author &

YearJournal Description

3 Boskovic Ivana et

al;January 2013

Research Journal of Chemistry and Environment

Results indicate the possibility of use of red mud as a good initial material for geopolymer preparation. The compressive strength results are within the range of 10.2 MPa to 17.2 MPa under the specified conditions of raw mixture preparation. SEM analysis confirms the homogeneity of samples. The detection of amorphous phase is quite hard.

4 Jian He et al;

December 2012

Elsevier 11 A new type of geopolymer composite was synthesized from two industrial wastes, red mud (RM) and rice husk ashThe studied geopolymers have compressive strengths of up to 20.5MPa, which is comparable to most Portland cements.A few barriers, such as long curing duration makes it practically difficult.

SUMMARY OF THE SURVEY Al-Si minerals are more soluble in sodium based activators compared to Potassium based activators.Silica in Na2SiO3 plays important role in GPC since it is the initiator of Geopolymerisation.Blending of Alkaline activators 24 hours prior to concreting enhance polymerization process and prevents bleeding and segregation.Heat released during curing of Fly Ash based GPC is much less(40oC) when compared to typical concrete(65 to 70oC).This makes it an advantage over OPCC for large structures like Dams, weirs and tanks.Micro silica can be added at a rate of 5-15% by weight of cement while Red Mud can be used upto 30%. Fly Ash and GGBS can be used upto 100% in GPC.Metakaolin based GPC shows high compressive strength due to high fraction of pure geopolymer binder and less micro pores and micro cracks.

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MATERIALS USED

Binding material - GGBS & Red mud

Fine Aggregate – 50% Copper Slag & 50% River Sand

Coarse Aggregate – 10mm & 20mm HBG metal

Fibres – Steel(1%), Polypropylene(0.5%), Banana(0.5%)

Alkaline solution – Sodium Hydroxide(NaOH) of molarity 10M & Sodium Silicate(Na2Sio3)

Superplasticizer – Conplast SP-430 (Sulphonated naphthalene formaldehyde based)

Water – Potable water

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RED MUD GGBS

COPPER SLAG

RIVER SAND

MATERIALS USED (Contd…)

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20 MM SIZE 10 MM SIZE

SODIUM SILICATE SODIUM HYDROXIDE

MATERIALS USED (Contd…)

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STEEL FIBRE POLYPROPYLENE FIBRE

BANANA FIBRE

MATERIALS USED (Contd…)

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MATERIAL PROPERTIES

Red Mud:

For the study, Red Mud is obtained from MALCO, near Mettur Dam in Salem, Tamil Nadu.By Pycnometer investigation, the specific Gravity(G) is found to be 1.67.

Ground Granulated Blast Furnace Slag(GGBS):

GGBS used for this study is obtained from Nandi Cements, Bengaluru which is processed from slag obtained from JSW Steel plant, Bellary and SAIL, Bhadravathi. By Pycnometer investigation, the specific Gravity(G) is found to be 2.19.

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MATERIAL PROPERTIES(Contd…)

Copper Slag:

Copper Slag used for this study is obtained from Sterlite Industry, Thoothukudi .The fineness modulus of the copper slag is 7.14. Uniformity coefficient is 2.37. Coefficient of curvature is 1.053. By Pycnometer analysis, G is found to be 4.01

River sand:

In this study, River sand is used as the fine aggregate. It is obtained from a local quarry near Nagercoil. The fineness modulus of the river sand is 6.34. Uniformity coefficient is 2.37 and the Coefficient of curvature is1.053. By Pycnometer analysis, G is found to be 2.54

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MATERIAL PROPERTIES(Contd…)

Coarse Aggregates:

In this study, coarse aggregates of size 20mm and 10mm are to be used. It is obtained from a local quarry near Nagercoil. Using Impact testing Machine, the impact value of coarse aggregate of size 20mm is 13.20% and for 10mm the impact value is 17.720%.

Alkaline Solution: The solution comprised of Sodium hydroxide and Sodium Silicate is used as alkaline solution. Sodium silicate solution (SiO2-29.4%, Na2O-14.73% and H2O-55.9% by mass) and sodium hydroxide solution of 10M concentration (400 gm in 1 kg of water) is used.

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MATERIAL PROPERTIES(Contd…)

Fibres:

Hybrid fibre usage (A mixture of metallic, non-metallic and natural) is done in this investigation .

Metallic type - Steel fibre (Corrugated type, aspect ratio 50) Non-metallic type - Polypropylene fibre (fibrillated type,6 mm size)Natural Type - Banana fibre of aspect ratio 50.

Superplasticizer:

The sulphonated naphthalene-formaldehyde (Conplast SP-430) is used in this experiment to improve workability.

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METHODOLOGY

Four different mixes are made in the following ratio Mix A(70%GGBS & 30% RM), Mix B(73%GGBS & 27% RM), Mix C(76%GGBS & 24% RM), Mix D(80%GGBS & 20% RM) along with the control mix.

Sodium Hydroxide pellets (10M) & Sodium Silicate solution are together used as alkaline solution.

39 cubes(150*150*150 mm size) & 24 prism(100*100*500 mm size) specimens are casted.

Specimens are heat cured for 24 hours at a temperature of 40-50 0C.

Properties are tested after 7 days and 28 days. Durability aspects are tested after 28 days.

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Durability tests are carried out as per some specifications for specified tests.

Saturated water absorption ( SWA ) tests were carried out on 150 mm cube specimens at the age of 28 days curing as per ASTM C 642.

The acid attack testing procedure was conducted by immersing concrete cube specimens of 150 mm size after the specified initial curing in a tub containing 5% H2SO4 for 28 days.

The sulphate attack testing procedure was conducted by immersing concrete cube specimens of 150 mm size after the specified initial curing in a tub containing 5% Sodium Sulphate for 28 days.

METHODOLOGY (Contd…)

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For Alkalinity test, the broken pieces of tested specimen were again broken into small pieces using hammer and ball mill and then powdered. The powdered samples (say 20gm) was put into100ml distilled water. The aqueous solution was allowed to stand for 72 hours and the pH is measured by pH meter.

The carbonation depth test was carried out according to RILEM CPC – 18 recommendations. 1% phenolphthalein solution is mixed in 70% ethyl alcohol and the same is sprayed onto the concrete surface which has been cleaned for dust and loose particles. Phenolphthalein is a colourless acid indicator which turns red or pink when the pH is above a value of 9.5.

METHODOLOGY (Contd…)

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METHODOLOGY (Contd…)Pretreatment of Banana fibres

Pretreatment of Banana fibres are done by immersing it in 6 % NaOH for 2 hours to overcome the bio-degradability of natural fibres.

They are then washed thoroughly by running water. It is then filtered and dried at 80oC for 24 hours.

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STAGES OF MIXING & CASTING

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STAGES OF MIXING & CASTING (Contd…)

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HEAT CURING PROCESS

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TESTING PROCESS

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DURABILITY TESTS

WATER ABSORPTION

SULPHATE ATTACKACID ATTACK

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DURABILITY TESTS (Contd…)

CARBONATION DEPTH

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RESULTS AND DISCUSSIONS

Property Compressive strength Flexural Strength

Period 7 days 28 days 7 days 28 days

MIX Pu fu Pu fu Pu fu Pu fu

R 436.35 19.40 692.84 30.81 5.68 2.84 9.70 4.85

A 412.50 18.34 660.00 29.34 5.50 2.75 13.78 6.89

B 393.75 17.50 630.00 28.00 5.25 2.63 13.24 6.62

C 380.75 16.92 635.00 28.19 4.60 2.30 12.66 6.33

D 442.50 19.66 737.50 32.80 5.85 2.93 14.24 7.12

Pu - Average Ultimate load in KN, fu - Average ultimate strength in N/mm2

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R A B C D0

5

10

15

20

25

30

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Compressive strength(N/mm2) 7 daysCompressive strength(N/mm2) 28 daysFlexural strength(N/mm2) 7 daysFlexural strength(N/mm2) 28 days

MIX DESIGNATION

MECHANICAL PROPERTY

RESULTS AND DISCUSSIONS (a comparison)

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MixDesignation

Average Weight Loss

Average Compressive

Strength (loss/gain)

Kg % N/mm2 %

R No significant 25.46 14 (loss)

D changes were seen 40.34 23 (gain)

1. Saturated Water Absorption

After Specified Period of 28 days, there were no specific changes in weight or compressive strength both in Control mix and Mix D which shows GPC is dense in nature and thus can prevent ingression of environmental effluents through its pores.

2. Acid Attack Test

RESULTS AND DISCUSSIONS (Contd…)

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RESULTS AND DISCUSSIONS (Contd…)

MixDesignation

Average Weight Loss

Average Compressive

Strength (loss/gain)Kg % N/mm2 %

R No significant 26.40 12 (loss)

D changes were seen 38.38 17 (gain)

3. Sulphate Attack Test

4. Alkalinity

For Mix R, Alkalinity measure = 12.20 while for Mix D, Alkalinity = 13.10.

5. Carbonation Depth

For Mix R, the maximum penetration of pink colour (carbonation depth) is about 8.60 mm while For Mix D, maximum penetration is about 10.40 mm.

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CONCLUSIONBased on the investigation carried out on the GGBS and Red Mud based Geopolymer Concrete, the following conclusions were drawn

1.Geopolymer concrete is more ecological and has the prospective to swap ordinary Portland cement concrete from top to bottom in many applications such as precast elements.

2. It helps to prevent global warming and it utilizes the waste materials effectively thereby reducing the risk of waste disposal and safeguards the dwindling natural resources. 3. Mix A performs better than Mix B and Mix C on account of the increased binder content.

4. Among all the mixes, Mix D shows best mechanical properties owing to the incorporation of hybrid fibres

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(steel fibre + Polypropylene fibre + Banana fibre) and reduction of Red Mud.

5. It can be seen that, there is about 30% increase in flexural strength of fibre incorporated GPC when compared to OPCC.

6. Specimens attained their properties at a curing temperature of 40-50oC. Hence sunlight curing is sufficient for the cited mix proportions which further overcomes a disadvantage of GPC and makes it adaptable for on-site constructions.

7. GPC exhibited strength gain of 23% when contacted with 5% Sulphuric Acid and 17% with 5% Sodium Sulphate while OPCC suffered losses in both cases.

8. Usage of copper slag reduces the risk of damages caused by alkali–silica reaction and provides higher resistance to environmental impacts.

CONCLUSION (Contd…)

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SCOPE FOR FUTURE WORK

Concert of M-Sand in lieu of River sand can also be evaluated. If it works out, then the cited work will be of great success since binder and fine aggregate are completely eco-friendly.

The performance of hybrid combination of fibres can be tested for all the four mixes.

The same mix combinations can be tested for different molarity levels of NaOH.

Durability tests can also be performed for all the mixes and as an outcome, the most effective combination of fibres can be finalized.

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Durability test for a longer duration could be conducted for enhanced understanding.

It was found in this research that due to the difference in chemical properties, some standards test on durability such as RCPT and phenolphthalein indicator did not work well for alkali activated binder.

A review of the current standard tests which were initially developed for normal concrete and its possible modification to be used for alkali activated binder is needed.

SCOPE FOR FUTURE WORK (Contd…)

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REFERENCES

1. Abishek H N and M U Aswanth “Strength studies of Red Mud based Geopolymer concrete” International Journal of Emerging Trends in Engineering and Development; Issue 2 vol-6, Sep 2012; pp 10-32, 2012. 2. Ambily P.S, Madheswaran C.K, Lakhsmanan.N, Dattatreya J.K, Jaffer Sathik S.A “Experimental studies on Shear behaviour of reinforced Geopolymer concrete thin webbed T-beams with and without fibres” International Journal Of Civil And Structural Engineering; Volume 3, No 1, 2012, pp 128-140.

3. Antonio M. Arino and Barzin Mobasher “Effect of Ground Copper Slag on Strength and Toughness of Cementitious Mixes” ACI Materials Journal/January-February 1999, pp 68-74.

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REFERENCES (Contd…..)4. Boskovic Ivana, Vukcevic Mira, Krgovic Milun, Ivanovic Mileta and Zejak Radomir “The Influence of Raw Mixture and Activators Characteristics on Red-Mud based Geopolymers” Research Journal of Chemistry and Environment Vol.17 (1) January (2013) vol-17, pp 34-40,2013.

5. Brock William Tomkins “Chemical Resistance of Geopolymer Concrete against H2SO4 & NaOH” A dissertation submitted to Faculty of Engineering and Surveying, University of Southern Queensland; October 2011.

6. Dattatreya J K, Rajamane NP, Sabitha D, Ambily P S and Nataraja MC “Flexural behaviour of reinforced Geopolymer concrete beams” International Journal Of Civil And Structural Engineering Volume 2, No 1, 2011, pp 138-159.

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REFERENCES (Contd…..)7. Ganapati Naidu, A.S.S.N.Prasad, S.Adiseshu and P.V.V.Satayanarayana “A Study on Strength Properties of Geopolymer Concrete with Addition of G.G.B.S”, International Journal of Engineering Research and Development Volume 2, Issue 4 (July 2012), pp 19-28.

8. Gokulram H, Anuradha R. Strength Studies on Polypropylene Fibre Reinforced Geopolymer Concrete using M-Sand” International Journal of Emerging Trends in Engineering and Development, (March 2013) vol-2, pp 242-250.

9. Jian He “Synthesis and Characterization of Geopolymers for infrastructural Applications” A Dissertion Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College; August 2012.

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REFERENCES (Contd…..)

10. Lloyd N and Rangan B “Geopolymer Concrete with Fly Ash” Second International Conference on Sustainable Construction Materials and Technologies; Volume 3, pp 1493-1504.

11. Mira Vuk evi, Danka Turovi, Milun Krgovi, Ivana Bo kovi, Mileta Ivanovi and Radomir Zejak “Utilization of Geopolymerization For obtaining Construction Materials Based on Red Mud” Professional article; ISSN 1580-2949; pp 99-104, 2013.

12. Ng T.S, Htut T.N.S and Foster S.J. “Mode I and II fracture behaviour of steel fibre reinforced high strength geopolymer concrete: an experimental investigation” 2010 Korea Concrete Institute, pp 1501-1511.

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REFERENCES (Contd…..)

13. Savstano Jr H, Santos S.F, and Agopyan V. “Sustainability of vegetable fibres in construction” Universidade de São Paulo, Brazil, pp 55-81.

14. Supraja V, Kanta Rao M. “Experimental study on Geo-Polymer concrete incorporating GGBS” International Journal of Electronics, Communication & Soft Computing Science and Engineering; ISSN: 2277-9477, Volume 2, Issue 2vol-2, pp 11-15.

15. Susan, Bernal, Ruby, De Gutierrez, Silvio, Delvastro, Erich and Rodriguez “Performance of Geopolumer Concrete Reinforced With Steel Fibres” IIBCC 10th international Inorganic bonded Fiber composites conference; São Paulo–Brazil; November 2006, pp 156-167.

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