View of STRENGTH ANALYSIS OF CONCRETE EMBEDDED WITH COCONUT FIBER AND CLASS-F FLY ASH

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Vol.04, Issue 12, December 2019, Available Online: www.ajeee.co.in/index.php/AJEEE

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STRENGTH ANALYSIS OF CONCRETE EMBEDDED WITH COCONUT FIBER AND CLASS-F FLY ASH

1Raghvendra Singh Chandel, ²Prof. Anil Sanodiya, ³Prof.Charan Singh Thakur Department of Civil Engineering, SRGI, Jabalpur, Madhya Pradesh, India

Abstract - The aim of the investigation is to study the variation in the strength characteristics of concrete, for the proportion of M30 grade. In each mix containing different percentages of fly ash is replaced by means of cement starting from 0% as normal concrete, i.e. controlled concrete 10%, 20%, and 30%, were used. The characteristics behavior of concrete is further enhanced by embedding coco-nut fibres with variable fibre sizes.

Keywords: Concrete, coconut fibers, fly ash, mechanical properties 1 INTRODUCTION

The structural needs our country is changing day by day & with concrete is a main constituent of construction material of this structural system, it is necessary to enhance its characteristics in terms of strength & durability. It is also desirable to compensate concrete in the form of using waste materials that results in a cut down in the cost by the use of admixtures such as fly ash, silica fume, coco-nut fibres etc. as partial replacement of cement. There are many ways to achiev the above objectives to develop new concrete composites.

2 LITERATURE REVIEW

The number of significant results has been reported on the use of fly ash in concrete & coconut fibers in concrete.

Saravana Raja Mohan, and co- workers carried out experiment investigation to evaluate the properties of fly ash based coconut fiber composite cement was replaced with five percentages (10%, 15%, 20%, 25%, &

30%) of class c fly ash. Four percentages of coconut fibers (0.15, 0.3, 0.45 &

0.60%) having 40mm length were used.

The fly ash based coconut fiber reinforced concrete shows a better performance than ordinary concrete.

The test result showed that the maximum compressive strength was obtained for a mix having a fiber length of 40mm 10% fly ash & fiber content of 0.15% by weight and increase in strength over plain cement concrete was found to be 27.51 Mpa. The 7 day compressive strength of fly ash based fiber concrete was found to be as high as 18.95 Mpa which is about 25.91% more than ordinary concrete. Similarly 28 day compressive strength was found to be about 27.51 Mpa and is 45.81% more than the ordinary concrete.

The maximum value of splitting tensile strength obtained is 4.75Mpa which is about 35.71% more than ordinary concrete the maximum strength was obtained for a mix with fiber length 40mm, fiber content 0.3%

by weight & 15% fly ash replacement of cement.

The maximum flexural strength obtained for coconut fiber reinforced concrete was 4.65 Mpa and that plain cement concrete was 4 Mpa.

A. Zuraida, S. Norshahida and co-workers. Carried out experimental investigation on effect of fiber length variation on mechanical and physical properties of coir fiber reinforced cement albumen composite, Albumen protein was added as a binder and the coir fiber with the length of (2.5, 5, 10 and 20mm) was used as partial replacement of the cement mixture. Flexural strength and compressive strength, Bulk density moisture content and water absorption were investigated the test results showed that increase in fiber length increase the flexural strength. Incorporation of long fiber into cement paste however decreased the workability and thus introduced voids which resulted in low density. In fact, the water absorption &

moisture content were also increased.

Alida Abdullah, and co-workers Carried out experimental investigation on the effect of natural fiber content on the physical & mechanical properties of composite cement reinforce with coconut fiber. The mix design was based on 1:1 for cement sand ratio and 0.55 was fixed for amount of water per cement ratio.

Coconut fiber was added as reinforcement and replacing the composition of sand. Composites wete developed base on 3% wt, 6%wt, 9% wt, 12% wt & 15%wt of coconut fiber by

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mixing & curing process. Composite were cured in water for 7, 14 & 28 days the test results showed that the composite reinforced with 9% wt of coconut fiber demonstrated the highest strength of modulus of rapture and compressive strength.

Wilson O Tablan carried out the experimental investigation on effect of coconut fiber as reinforcement to concrete on its flexural strength and cracking behavior. 25% coconut fiber was added as reinforcement. The ratio of 1:2:4 mixture of concrete was used in making the specimen & curing the period of 28 days. The result showed that the concrete reinforced with coconut fibers yielded a higher flexural strength compared to concrete without coconut fiber reinforcement. More ever the concrete with coconut fiber indicated transformation from abrupt to gradual failure of the specimens and splitting when ultimate load was applied hence the added coconut fibers enhanced the flexural strength of the concrete.

Tan Eng slang carried out experimental investigation on effect of coconut fiber & egg albumen to properties of the concrete such as the compressive strength & flexural strength. The three types of concrete mixture were concrete containing 0.1%

coconut fiber & 1% egg albumen, concrete containing 0.5% coconut fiber

& 0.5% egg albumen and concrete control sample from analysis showed that the both the additives of coconut fiber & egg albumen with concrete in different percentage show improvement in the development of the strength. By compairing concrete containing 0.1%

coconut fiber & 0.1% egg albumen with concrete containing 0.5% coconut fiber

& 0.5% egg albumen, the strength of lower percentage additive was higher than the higher percentage of additive.

Baruah and Talukdar carried out experimental investigation the properties of plain concrete and coconut fiber reinforced concrete with different fiber volume fractions ranging from 0.5 to 2% The misc design for plain concrete was 1:1:67:3.64 with W/C of 0.535 The coconut fiber having length of 4cm and with volume fraction of 0.5, 1, 1.5 and 2% were added to prepare CFRC. The test result showed that coconut fiber reinforced concrete with 2% fibers

showed better results among all volume fractions. The compressive strength splitting tensile strength modulus of rupture and shear strength of coconut fiber reinforced concrete with 2% fibers by volume fraction were increased up to 13.7, 22.9, 28 & 32.7% respectively as compared to those of plain concrete.

Reis investigated the mechanical characterization flexural strength, fracture toughness & fracture energy of concrete reinforced with natural coconut fiber. The test results showed that fracture toughness & fracture energy of coconut fiber reinforced concrete were higher than that of other fibers reinforced concrete, flexural strength was increased up to 25% with coconut fiber only.

Siddique carried out experimental investigation to evaluate the mechanical properties of concrete mixes in which cement was partially replaced with class F fly ash, cement was replaced with 10%, 20%, 30%, 40%, 50% of class F fly ash by weight the test results showed that the compressive strength, splitting tensile strength &

flexural strength of fly ash concrete mixes with 10% to 50% cement replacement with fly ash showed improvement in the results as compared to concrete.

2.1 Fly Ash:

Fly ash is a by-product from coal based electricity power plant. The coal used in these power plants is mainly composed of combustible elements such as carbon, hydrogen and oxygen (nitrogen and sulphur being minor elements), and non-combustible impurities (10 to 40%) usually present in the form of clay, shale, quartz, feldspar and limestone.

At high temperature zone in the furnace, the combustible elements of the coal are burnt off, whereas the mineral impurities of the refuse chemically recombine to produce various crystalline phases. The molten ash is entrained in the flue gas and cools dry, when leaving the combustion zone (e.g. from 1500˚c to 2000˚c in seconds), into spherical, glassy particles. Most of these particles fly with the flue gas stream and are therefore called fly ash. The fly ash is collected in electrostatic precipitators or bag houses and the finesses of fly ash

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can be controlled by how and where the particles are collected.

2.2 Points Should be Understood Using fly ash based technology:

1. It is understood that, fly ash is not a waste, but a highly potential

2. Building material.

3. It is learnt that the fly ash has technical edge in enhancing the durability of concrete.

4. It opened up the awareness about the new business opportunities in packing and transportation of fly ash like a cement industry.

5. It is learnt that the use of fly ash is mandatory as per the government directives.

2.3 Reasons for low level utilization of fly ash:

The current low level utilization of the fly ash is mainly due to:

1. Strong myths that fly ash is a inferior building material.

2. Inadequate promotion of the technology.

3. Lack of confidence in the fly ash based technologies.

4. Lack of proper training and demonstration facilities.

5. Higher cost of production of building material using fly ash.

6. Non availability of dry fly ash collection facilities at many stations.

7. Easy availability of land with topsoil at cheap rates for manufacturing

8. Conventional bricks.

9. Lack of proper co-ordination between thermal plants and ash users.

10. Inadequate government policies and codes.

2.4 Fly Ash Based Innovative and Commonly Produced Building Products are available in India:

1. Cellular lightweight concrete (CLC) blocks.

2. Fly ash based polymer composites as wood substitute.

3. Fly ash based Portland pozzolana cement.

4. Ready mixed fly ash concrete.

5. Fly ash sand lime gypsum (cement) bricks/blocks.

6. Clay fly ash bricks 2.5 Classifications of Fly Ash:

Astm – C618-93 [1] categorizes fly ash into the following three

Categories

1. Class N fly ash: Raw or calcined natural pozzolanas such as some diatomaceous earths, opaline chart and shale, stuffs, volcanic ashes and pumice come in this category. Calcined kaolin clay and laterite shale also fall in this category of pozzolanas.

2. Class F fly ash: Fly ash normally produced from burning anthracite or bituminous coal falls in this category. This class of fly ash exhibits pozzolanic property but rarely if any, self- hardening property.

3. Class C fly ash: Fly ash normally produced from lignite or sub bituminous coal is the only material included in this category. This class of fly ash exhibits pozzolanic property but rarely if any, self hardening property.

2.6 BIS Categorizes Fly Ashes into the following two categories:

1. Class F fly ash: The burning of harder, older anthracite and bituminous coal typically produces class F fly ash. This fly ash is pozzolanic in nature, and contains less than 10% lime (cao).

2. Class C Fly ash: Fly ash produced from the burning of younger lignite or sub bituminous coals are classified as class C fly ash. Fly ash is one of the most extensively used by product materials in the construction field resembling Portland cement (Pfeifer, 1969).

It is an inorganic, noncombustible, finely divided residue collected or precipitated from the exhaust gases of any industrial furnace (Halstead 1986). Most of the fly ash particles are solid particles spheres and some particles, called cenosperes, are hollow

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(Kosmatka et al. 2002). Also present are plerosheres, which are spheres containing smaller spheres inside. The particle sizes in fly ash vary from less than 1 mm to more than 100 mm with the typical particle size measuring under 20 mm. Their surface areas is typically 300 to 500 m²/kg, although some fly ashes can have surface areas as

low as 200 m²/kg and as high as 700 m²/kg. Fly ash is primarily silicate glass containing silica, alumina, iron, and calcium. The relative density or specific gravity of fly ash generally ranges between 1.9 and 2.8 and the colour is generally gray or tan (Halstead, 1986).

3 EXPERIMENTAL PROGRAM

Table No. 01: Casting and Curing of M30 Grade of Concrete with 0% Fly Ash

Sl.

No. Particular Mix

Design Code No. of

Specimen Curing period

in days Remark

1 Cube M30 M1 9 no’s 7, 14,28

Cube size 150 x 150x 150mm

Table no. 02: Casting and curing of M30 grade of concrete with 10% cement replaced by fly ash .

Sl. No. Particular Mix

Design Code No. of Specimen

Curing period

in Days Remark

1 Cube M30 M2 9 no’s 7, 14,28

Cube size 150 x 150 x 150mm

Table no. 03: Casting and curing of M30 grade of concrete with 20% cement replaced by fly ash.

Design Code No. of Specimen

1 Cube M30 M3 9 no’s 7, 14,28 Cube size

150X150X 150mm

Table No. 04: Casting and curing of M30 grade of concrete with 30% cement replaced by fly ash.

Design Code No. of Specimen

1 Cube M30 M4 9 no’s 7, 14,28 Cube size

150X150X 150mm

3.1 Testing of Materials:

Cement:

Ordinary Portland Cement of 53 Grade confirming to IS: 8112-1989 was used in the investigation

Table No. 05: Chemical Composition of OPC

OXIDE PERCENTAGE

CONTENT

CAO 60-67

SO2 17-25

AL2O3 3.0-8.0

FE2O3 0.5-6.0

MGO 0.1-4.0

ALKALIES (K20M, NA20) 0.4-1.3

SO3 1.0-3.0

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Table No. 06: Physical Properties of Cement

SERIAL NO PROPERTIES CHART RESULTS REQUIREMENTS AS PER IS:8112- 1989

1. Specific gravity 3.15 -

2. Finness (specific gravity) 301m2/kg Should not be less Than 225m2/kg

3. Normal consistency 30% -

4. Setting time in min.

1. Initial setting time

2. Final setting time 130

197 Should not be less than 30min Should not be exceed 600min.

5. Soundness Test:

By 1. Le Chatelier

2. Auto clave method. 0.5mm

0.0935% Should not exceed 10mm Should not exceed 0.8%

6. Compressive strength 1. 3 – days 2. 7 – days 3. 28 -days

34.5N/mm² 45.50N/mm² 65.00N/mm²

Should not less than 27N/mm² Should not be less than 37N/mm² Should not be less than 53N/mm² 7. Temperature during testing 27 ˚c Min 25 ˚c and Max 29˚c

3.2 Fly Ash:

Fly ash obtained from Satana Thermal Power Plant, M.P with specific Gravity = 2.3.

Table No. 07: Chemical composition of F-fly ash

Serial No. Chemical Analysis Class F-Fly Ash (%)

ASTM Requirement

C618 (%).

1. Silicon dioxide sio2 55.3 -

2. Aluminum oxide al2o3 25.70 -

3. Ferric oxide, fe2O3 5.30 -

4. Sio2 + al2o3 + fe2O3 85.9 70.0 minimum

5. Calcium oxide, cao 5.60 -

6. Magnesium oxide mgo 2.10 5.0 maximum

7. Titanium oxide tio2 1.30 -

8. Potassium oxide k2o 0.60 -

9. Sodium oxide nao 0.40 1.5 maximum

10. Sulfur trioxide so3 1.40 5.0 maximum

11. LOI (1000˚c) 1.90 6.0 maximum

12. Moisture 0.30 3.0 Maximum.

Fine Aggregate (FA):

Table No. 08: Sieve analysis of fine aggregate

SR.

NO IS SIEVE SIZE

Weight retained

(gm)

Corr ecti on

Corre cted weigh t

Cumu lative weigh

t retain

ed

Cumulative percentage

weight retained

passing

1. 10mm - - - - - -

2. 4.75mm 25 +0.5 25.5 25.5 2.55 97.45

3. 2.36mm 29 +0.5

8 29.58 55.08 5.508 94.50

4. 1.18mm 209 +4.1

8 213.1

8 268.2

6 26.826 73.18

5. 600µ 317 +6.3

4 323.3

4 591.6

0 59.16 40.84

6. 300µ 350 +7.0 357 948.6

0 94.86 5.16

7. 150µ 50 +1.0 51.0 999.6 99.96 0.04

3.3 Properties of Fine Aggregate:

Fineness modulus of fine aggregate = cumulative percentage weight retained/100 Fineness modulus = 288.864/100

= 2.88 Specific gravity = 2.68

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Water absorption = 0.86%

Silt or clay content = 0.5%

Bulk density = 1520kg/m³

Grading = well graded (zone II).

3.4 Coarse Aggregate:

Table No. 9: Sieve analysis of coarse aggregate

Sr.

No Is sieve

size Weight retained

(gm) Cumulative weight retained

Cumulative percentage weight

retained

passing.

1. 63.00 0.00 0.00 0.00 100

2. 40.00 0.00 0.00 0.00 100

3. 20.00 2000 2000 20.00 80.00

4. 12.50 7580 9580 95.80 4.20

5. 10.00 220.0 9800 98.00 2.00

6. 8.00 120.0 9920 99.20 0.80

7. 6.30 40.00 9960 99.60 0.40

8. 4.75 20.00 9980 99.80 0.20

9. pan 20.00 10,000 - 0.00

3.5 Properties of Coarse Aggregate:

Fineness modulus of coarse aggregates = cumulative percentage weight retained/100 Fineness Modulus = 512.40/100

= 5.12 Specific gravity = 2.7 Water absorption = 1.12%

Impact value = 11.76%

Bulk density = 1440kg/m³.

3.6 Water [IS: 456-2000]:

Water used for both mixing and curing should be free from injurious amount of deleterious materials such as acids, alkalies, salts, organic materials etc. Potable water is generally considered satisfactory for mixing and curing concrete. In present work potable tap water was used.

3.7 Slump Cone Test:

Table No. 10: Description of workability and magnitude of slump

Description of workability Slump in mm

No slump 0

Very low 5 – 10

Low 15 – 30

Medium 35 – 75

High 80 – 155

Very high 160 to collapse

Table No. 11: Workability of various concrete mixes design for slump cone test is as follows

Mix design codes Slump cone test in mm.

M1-MIX (normal concrete) 38

M2-MIX (10% fly ash) 42

M3-MIX (20% fly ash ) 43

M4-MIX (30% fly ash ) 45

M13-MIX (30% fly ash,0.25% fiber) 47 M22-MIX (30% fly ash, 0.5% fiber) 48

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3.8 Compaction Factor Test:

Table No. 12: Workability of various concrete mix design for compaction factor test

Serial No. Mix Design Code Compaction Factor

1 M1 0.81

2 M2 0.82

3 M3 0.84

4 M4 0.85

5 M13 0.87

6 M22 0.90

3.9 Details of Specimens Used:

150mm x 150mm x 150mm cube specimens for Compressive strength.

Figure 1: Mixing of materials and casting

Figure 2: Curing of Specimens

3.10 Test for Compressive Strength of Concrete (IS: 516-1959):

Table No: 13: Compressive Strength of Grade M30 as M1, M2, M3, M4,

Mix M-1 M-2 M-3 M-4

Fly as

(%) 0 10 20 30

Test age

(days) 3-3 SAMPLES

COMPRESSIVE STRENGTH (N/mm²)

7 22.0 22.6 23.3 23.7

14 25.0 26.7 27.7 28.4

28 29.5 30.0 32.2 32

4 CONCLUSIONS

Compressive strength, of fly ash based reinforced concrete specimens were higher than the plain concrete (Control Mix) and fly ash concrete specimens at all the ages. The strength differential between the plain concrete specimens and fly ash reinforced concrete specimens became more distinct after at 28 days.

The replacement of cement with 20% and 30% fly ash reduced the compressive strength of concrete.

It has been observed that as the percentage of fly ash increases the compressive strength increases initially, on further increase in its percentage reduces its compressive strength.

REFERENCES

1. Saravana raja mohan, P.Jayabalan, A Rajaraman on properties of fly ash based coconut fiber composite, American

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Journal of Engg and Applied Science 5(1):29-34,2012

2. A. Zutaida, S. Norshahida, I.Sopian and H. Zahurin (malaysia) on effect of fiber length variation on mechanical and physical properties of coir fiber reinforced cement albumen composite. IIUM Engg Journal Vol.12 No 1, 2011.

3. Alida Abdullah, Shamsul Baharin Jamaludin, Mazlee Mohd Noor, Kamarudin Hussin on Composite Cement Reinforced Coconut Fiber: Physical and Mechanical Properties Australian Journal of Basic and Applied Sciences, 5(7): 1228- 1240, 2011

4. Wilson o. tablan Flexural Strength of Concrete Beams Containing Twinned Coconut Fibers Vol 5 No.1 December 2007 ISSN: 2094-1064

5. Majid Ali Coconut fibre: A versatile material and its applications in engineering Journal of Civil Engineering and Construction Technology Vol. 2(9), pp. 189-197, 2 September, 2011

Available online at

6. Tan eng slang effect of coconut fibre and egg albumen in concrete for greener environment

7. Ben Davis on Natural Fibre Reinforced Concrete.

8. Baruah and Talukdar properties of plain concrete and coconut fiber reinforced concrete Journal of Civil Engineering and Construction Technology Vol. 2(9), pp.

189-197, 2 September, 2011 Available

online at

9. IS: 8112-1989 Specifications for 43- Grade Portland cement, Bureau of Indian Standards, and New Delhi, India.