A BRIEF EXPERIMENTAL STUDY ON METAKOLIN ADMIXED CONCRETE WITH AND WITHOUT RICE HUSK ASH

International Journal of Innovative Research in Advanced Engineering (IJIRAE) ISSN: 2349-2763 Issue 06, Volume 3 (June 2016) www.ijirae.com

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A BRIEF EXPERIMENTAL STUDY ON METAKOLIN ADMIXED CONCRETE WITH AND WITHOUT RICE

HUSK ASH

Mahendrakar Kiran Kumar1 and C.Rajamallu2

1 M.Tech Student, Department of Civil Engineering, BITS, JNTUA University. 2 Head of Dept., Department of Civil Engineering, BITS, JNTUA University.

Abstract- The most important objective of this study is to evaluate the possibilities of usage of Metakaolin in concrete. The researches will also focus on the potentiality of hybrid blending by Metakaolin and rice husk ash. The latter mineral incineration could reduce the demands for fossil and electrical energy, required for producing mono-blends with Metakaolin. The development of a sound technology requires investigating effects exerted by the mineral admixture on the strength of the cementitious materials. Replacement percentage has to be varied to that end and different accounts of mixing water have to be considered. Strength should be recorded at early age and in the more mature state of material. This paper represents the results of an experimental investigations carried out to find the suitability of Metakaolin (MK) only and Metakaolin with and without rice husk ash (RHA) in production of concrete. In this experimental study the effect of MK and RHA on strength of the concrete was studied, the referral concrete M30 was made using 53 Grade OPC and the other mixes were prepared by replacing part of OPC with MK and MK with RHA. The replacement levels were 10%, 12.5%, 15%, 17.5% up to 20% (by weight) for Metakaolin. Test results indicate that use of replacement cement by Metakaolin in concrete has improved performance of concrete up to 15% to 20%.

Keywords: Ettringite, Metakaolin, CSH-Gel, Interfacial Transition Zone, Roofplast:sp-45.

I. INTRODUCTION

Sustainable construction practices necessitate a review of the current construction practices, including prevailing techniques and sources of raw materials. Waste materials and by-products that in the past have received little or no attention such as “Rice husk ash” & “Metakaolin” require further consideration. Supplementary cementitious materials (SCMs) have been widely used all over the world in concrete due to their economic and environmental benefits. Metakaolin is also one of such non conventional material which can be utilized beneficially in the construction industry. Metalaolin(MK) is a relative alumino-silicate pozzolan formed by burning purified kaolin or kaolinite clays at a specific temperature range and by grinding it to a high fineness. Metakaolin can be combined with calcium hydroxide to form hydrates. This contributes to improving properties of mortar and concrete. The reaction capacity of Metakaolin depends mainly on its mineral composition, on the raw kaolin source and on the conditions of production. With regard to workability and setting time, both metakaolins examined generally required more superplasticizer to achieve adequate concrete workability. Metakaolin is usually considered as a replacement for Portland cement, at a proportion of 8% to 20% of the weight of cement. Finally the entire paper represents the study of: The Effects exerted by the water to binder ratio on the strength of paste and mortar blended with Metakaolin; effects exerted by the Metakaolin content on strength properties of concrete; The effects of a joint MK and RHA content, replacing an equal portion by mass of the Portland cement, on some rheological and strength properties of mortar and concrete.

LITERATURE REVIEW

Door Dihn Dau VU et.al., Engineer Technologist Hanoi Polytechnic Viyatnam. Studies carried out on “Combined effect of Rice Husk Ash & Metakaolin: Strength properties of Metakolin blended paste and Mortor and concrete concludes that, with regard to workability and setting time, both Metakaolins examined generally required more superplasticizer to achieve adequate concrete workability. The finer Metakaolin caused the greatest reductions in workability, Metakaolin also shortened setting time of pastes by 35- 50% as compared to controls and 10-30% as compared to companion silica fume mixtures at the same Water cement. Greater shrinkage, both chemical and autogenous, was observed in mixtures containing SCMs as compared to ordinary cement and concrete control mixtures. MK235 mixtures showed the greatest chemical shrinkage, while MK mixtures showed the greatest autogenous shrinkage. Increased concrete strength, as compared to control and silica fume mixtures, was measured for concretes produced with both Metakaolins. The finer metakaolin, yielded the highest compressive, splitting tensile and flexural strengths, Metakaolins also yielded increased elastic moduli relative to controls. The positive influence of the Metakaolin fineness was more apparent at lower Water cement ratio.




With regard to the durability tests reported here, concretes produced with Metakaolin at 8% by mass cement exhibited reduced permeability, The coarser metakaolin produced greater reductions in permeability, yielding Coulomb values in the very low or low range for all water cement ratio. In general, the finer Metkaolin seemed more effective in enhancing concrete mechanical performance, while the coarser Metakaolin seemed more effective in improving concrete durability.

P.Muthupriya’s Investigation on Behavior of High Performance Reinforced Concrete Columns with Metakaolin

and Fly Ash as Admixture concludes that Use of metakaolin and flyash is necessary in the production of high performance concrete due to lower binder ratio and better hydration of cement particles, The compressive strength mainly depends on Metakaolin because of excellent pozzolanic properties to produce high strength concrete.

II. RESEARCH METHOD AND EXPERIMENTAL PROGRAMME

Obviously, the strength of mortar and concrete is intimately related to the strength of the hardened cement paste. The cement hydration products in the form of crystalline matter and gel govern these important properties. Strength of the maturing paste will vary with the type of binder used, with mixture proportions, and with the hydration conditions. The gel helps to maintain continuity in the hardening concrete by filling space between discrete elements on different structural levels. This holds for the crystalline matter on micro-level, as well as for the aggregate grains on meso-level. In preserving continuity, the internal bonding capacity is provided on which strength is relying. Several test methods are in use for the assessment of strength properties, i.e.: Direct test method, indirect test method, and Test method based on wave propagation. To assess mechanism of cement blending with Metakaolin and Rice Husk Ash underlying the strength of cement and concrete, it is necessary to determine physic-chemical properties in terms of composition and structure formed during the hardening process. This is complicated and time-consuming. Therefore, the direct method has been selected as major approach to determining strength in this study. Other methods have been used in a supplementary way for illustrating results obtained by the direct approach.

A. PROPORTIONING DETAILS Taking previous studies into consideration, work was carried out to know the mechanical properties of Concrete using Rice husk ash and Metakaolin represented by MRA mix and concrete with only metakolin represented as M mix as ac ement replacing sustainable cementious material. The study includes investigation of the compressive strength, split tensile strength, elasticity modulus, flexural strength of concrete and the compressive strength of cement for percentage replacement of cement by metakaolin and rice husk ash. In this study the cement were replaced to an extent of 40% varying the percentage of MK and RHA by different proportions as shown in the table below with the Grade of concrete (mix) chosen for the study was M30. The follow table shows the “% of Replacement of cement”.

MIX PROPORTION OF CONCRETE WITH METAKOLIN AND RICE HUSK ASH GROUP MIX % OF METAKAOLIN(MK) % OF RICE HUSK ASH(RHA) % OF CEMENT

M0 0 0 100 40 M1 10 0 90 70 M2 12.5 0 87.5 110 M3 15 0 85 150 M4 17.5 0 82.5 100 M5 20 0 80 85 MRA1 10 10 80 54 MRA2 12.5 12.5 75 40 MRA3 15 15 70 50 MRA4 17.5 17.5 65 60 MRA5 20 20 60 50

MIX PROPORTION OF CONCRETE WITH METAKAOLIN Ingredients

C M1 M2 M3 M4 M5

Cement(kg/m3) 437.78 394 383 372.11 361.17 350.22

Metakaolin(kg/m3) - 43.78 54.72 65.67 76.61 87.56




Water(kg/m3) 193.3 193.3 193.3 193.3 193.3 193.3

Fine aggregate (kg/m3) 644.65 644.65 644.65 644.65 644.65 644.65

Coarse aggregate(kg/m3) 1106.03 1106.03 1106.03 1106.03 1106.03 1106.03

MIX PROPORTIONING OF CONCRETE WITH MK & RHA Ingredients

MRA1 MRA2 MRA3 MRA4 MRA5 Cement(kg/m3) 437.78 350.22 328.34 306.44 284.56 262.66

Metakaolin(kg/m3) - 43.78 54.72 65.67 76.61 87.56 Water(kg/m3) 193.3 193.3 193.3 193.3 193.3 193.3

Fine aggregate (kg/m3) 644.65 644.65 644.65 644.65 644.65 644.65 Coarse aggregate(kg/m3) 1106.03 1106.03 1106.03 1106.03 1106.03 1106.03

Rice husk ash

- 43.78 54.72 65.67 76.61 87.56

B. MATERIALS INVESTIGATION

Cement: In the present work, ordinary Portland cement of 53 grade Birla Super conforming to IS 12269:1987 has been used. The quantity of Cement is selected as 400 kilogram per cubic meter of Concrete; Rice Husk Ash: Rice Husk ash was having specific gravity of this RHA is 2.10. Fine & Coarse Aggregate: Confirms to the specifications of IS 383: 1970 for graded aggregates and specific gravity; Roofplast SP45: product is known for their early strength, super plasticizer and water reducing admixture. The standards as per which our product is available complies with IS 9103-99, BS-5075 Part 3, ASTM-C-494 and Type G. Metakaolin: Physical properties of Metakaolin as follows.

PHYSICAL PROPERTIES OF METAKAOLIN CHEMICAL ANALYSIS OF METAKAOLIN (MASS %)

Appearance Cream ivory powder SiO2 52. 0

Bulk density(gm/cm) 0.416 Al2O3 46. 0

Specific gravity(gm/cm) 4.2 to 4.4 Fe2O3 0. 60

Moisture on board @ 105c% 0.6 TiO2 0. 65

Loss of ignition% 0.8 CaO 0. 09

Sieve residue on 350 mesh Nil MgO 0. 03 Particle size analysis (Sedigraph) d 50 3.20 microns Na2O 0. 10

C. RESULTS AND DISCUSSIONS RESULTS

MIX

AT FRESH STAGE AT HARDENED STAGE

Compaction factor

Slump value(mm)

Compressive strength of

Cubes(N/mm2) at 28 days

Compressive strength of Cylinders

28days

Split Tensile Strength(N/mm2)

28 days

C 87 40 37.04 36.5 2.79

2.79 2.79 MK (10%) 89 70 42 44.2 2.9

MK(12.5%) 89.7 110 46.78 47 3.01 MK(15%) 97.7 150 51.56 49.6 3.04

MK(17.5%) 85.6 100 48.53 48.1 3 MK(20%) 90 85 45.49 46.6 2.95 MK&RHA(10%) 80.5 54 34.67 48.3 2.81




MK&RHA(12.5%) 85.3 40 36.70 43.5 2.86 MK&RHA(15%) 79.5 50 34.44 45.7 2.97 MK&RHA(17.5%) 90 60 33.33 42 2.95 MK&RHA(20%) 86.5 50 32 40.56 2.83

DISCUSSIONS The compressive strength, split tensile strength & Elasticity modulus for M30 concrete of M3 for 28 days is higher than the other proportions, The compressive strength increases up to 15% of Metakaolin with concrete and additional replacement more than 17.5% replacement percentage decreases the compressive strength; Rice husk in concrete reduces the strength comparing with normal concrete, to compensate this reduction in compressive strength of 12.5% rise husk mixed concrete, Metakaolin is to be effectively used up to 12.5%, from the review of literature available from previous researchers The replacement of rice husk ash and Metakoline in concrete mix reduces workability for countering this reduction in workability of concrete mix it is must to utilize the Super plasticizer.

0

10

20

30

40

50

60

CO

MPR

ESSI

VE

STRE

NG

TH IN

MPa

Graph showing the Compressive Strength Test Results on Concrete Cubes of Standard size

C M1 M2 M3 M4 M5 MRA1

MRA2

MRA3

MRA4

MRA5

SPLIT TENSILE STRENGTH 2.79 2.9 3.01 3.04 3 2.95 2.81 2.86 2.97 2.95 2.83

2.652.7

2.752.8

2.852.9

2.953

3.053.1

Split

Ten

sile

Str

engt

h in

Mpa

Graph showing SPLIT TENSILE STRENGTH Test Results on Standard Size Cylinders




But whenever the Metakaolin only used in the concrete it is possible to get the desired workability upto percentage of 15% which is observed from M3 mix. The compressive strength for M1 concrete is 42 Mpa for 28 days. The compressive strength of MRA mix decreases comparing with Metakaolin concrete. The split tensile strength for M1 concrete is 2.9 Mpa. The higher strength may be attributed to content of Metakaolin up to increment of Metakaolin up to 15% like 3.04 Mpa which is observed from M3mix. The compressive strength for M3 concrete is 51.56 Mpa for 28 days respectively. The split tensile strength for M3 concrete is3.04mpa; The decrease in strength with respect to M5 canbe attributed to increase in the percentage of Metakaolin . The maximum elasticity modulus for M3 concrete is 1000mpa for 28 days. The elasticity of modulus of mix with rice husk ash MRA3.

III.CONCLUSIONS

Foremost objective of this study is thus realization of a sound technology providing significant economic benefits. Additionally, sustainability is promotion, The usage of Metakaolin in concrete is highly improves the strength, the results carried out the strength in 28 days; Metakaolin and rice husk ash mix reduces the workability, From the above results, it can be concluded that Metakaolin and rice husk ash can be effectively used in concrete; The inclusion of Metakaolin has desirable effect on concrete mechanical properties which is comparable to normal concrete. The usage of MK and RHA in concrete as cement replacement materials will lessen the CO2 being emitted during its manufacture and acts as a eco-friendly material reducing the Green house effect, Incorporation of these materials in cement helps in making it more economical.

REFERENCES

[1]. Door Dihn Dau VU et.al. Engineer Technologist Hanoi Polytechnic viyatnam. Studies carried out on “Combined effect of Rice Husk Ash & Metakaolin:Strength properties of metakolin blended paste and mortor and concrete”.

[2]. P.Muthupriya International Journal of Advanced Engineering Technology “Investigation on behaviour of high performance reinforced concrete columns with metakaolin and fly ash as admixture”.

[3]. Dr.K.Srinivasu, International Journal of Innovative Research in Science, Engineering and Technology Vol. 3, Issue 7, July 2014, “A Review on Use of Metakaolin in Cement Mortar and Concrete”.

[4]. Dr.D.V.Prasada Rao, Volume 7, Issue 1, Jan-Feb 2016, “Effect of Nano-Silica On Concrete Containing Metakaolin”.

AUTHORS

Mahendrakar Kiran Kumar is from the India. He received the Bachelor in Civil Engineering degree from the GPREC Kurnool, He is currently pursuing the M.Tech degree in JNTUA affiliated college. His research interests include Concrete Technology and Framed Structures.

C.Rajamallu is from the India. He currently Head of the Department of Civil Engineering at Bheema Institute of Technolgy and Sciences, Adoni. He obtained his Masters degree Osmania University of A.P. His research papers very help full for the students who are interested in Concrete. His research interests include Ground water resources, Irrigation structures.