iisrt khalid ahmed gour (civil)

International Journal of Mechanical, Civil, Automobile and Structural Engineering (IJMCAS)

Vol. 1, Issue. 1, April 2015 ISSN (Online): 2395-6755

7

Abstract - This study reports the results of an experimental

investigation carried out to study the effects of fly ash with glass fibre on the concrete and the optimum use of fly ash and glass fibre in concrete. Cement was partially replaced with three percentages (30%, 35%, and 40%) of class F fly ash by volume. Standard M30 grade of Concrete (OPC) is prepared as the standard reference

concrete. Compressive strength as well as splitting tensile strength of the concrete specimens was determined after curing for 28 days. Among the fly ash concretes, the optimum amount of fly ash replaced with cement content is about 35%, which provides 4.36% higher compressive strength and 5.07% higher splitting tensile strength as compared to OPC concrete. Glass fiber (or glass fibre) is a material consisting of numerous extremely fine fibers of glass. The glass fibre used is of Anti Crack High dispersion fibre. Anti-Crack HD (High

Dispersion) is an engineered AR-glass chopped strand designed for mixing in concrete and all hydraulic mortars where uniform dispersion of the fiber reinforcement is needed. Anti-Crack HD is typically used at a low level of addition to prevent cracking and improve the performance of concrete, flooring, renders or other special mortar mixes. They incorporate easily into mixes giving a very large number of distributed reinforcing fibers from a small weight of product. It reports the reinforcing efficiency of glass fibre

(0.5%, 1%, and 2%) addition in the fly ash concrete with cement replacement level. With the optimum percentage of fly ash, the various concentrations of glass fibres, the experimental test results showed that 35% fly ash with 1% glass fibres addition in concrete provided highest compressive strength up to 36.4% at 28 days and a splitting tensile strength up to 19.7% at 28 days.

Keywords Fly ash , Glass fibre , Splitting Tensile Strength , Compressive Strength.

I. INTRODUCTION

Concrete has become an indispensable construction material and it is now used in greater quantities than any other material. In the present context durability and sustainable development are key issues for development. Ordinary Portland cement has a high calcium base affecting the microclimate of concrete and mortar. The interface bond between the cement paste and aggregates can be improved with better pore structure and minimized micro cracks using mineral admixtures like Fly ash, Granulated blast furnace slag, Rice husk, Silica fume, etc. Out of the above, the use of fly ash has gained prominence due to growing awareness about the benefits and easy availability of the good quality Fly ash.

Fly ash is defined as the finely divided residue resulting from the combustion of ground or powdered coal, which is transported from the firebox through the boiler by flue gases. Fly ash is a by-product of coal-fired electric generating plants. Specifically, it is the unburned residue that is carried away from the burning zone in the boiler by the flue gases and then collected by either mechanical or electrostatic separators. The heavier unburned material drops to the bottom of the furnace and is termed bottom ash; this material is not generally suitable for use as a cementitious material for concrete, but is used in the manufacture of concrete masonry block.

Fly ash is a pozzolanic material. Fineness, loss on ignition, and chemical content are the most important characteristics of fly ash affecting its use in concrete. It must be in a dry form when used as a mineral admixture. It is a finely divided amorphous alumino-silicate with varying amounts of calcium, which when mixed with Portland cement and water, will react with the calcium hydroxide released by the hydration of Portland cement to produce various calcium silicate hydrates (C-S-H) and calcium-aluminate hydrates. Some fly ashes with higher amounts of calcium will also display cementitious behavior by reacting with water to produce hydrates in the absence of a source of calcium hydroxide. These pozzolanic reactions are beneficial to the concrete in that they increase the quantity of the cementitious binder phase (C-S-H) and, to a lesser extent, calcium aluminate hydrates, improving the long - term strength and reducing the permeability of the system. Both of these mechanisms enhance the durability of the concrete.

As per ASTM C618, Fly ash is classified into 2 categories, namely,

Class F Fly ash is the Fly ash normally produced from burning anthracite or bituminous coal that meets the applicable requirements as SiO2 + Al2O3 + Fe2O3 70%. It has pozzolanic properties.

Class C Fly ash is the Fly ash normally produced from lignite or sub-bituminous coal that meets the applicable requirements as SiO2 + Al2O3 + Fe2O3 70%. In addition to having pozzolanic properties, also has some cementitious properties. Some Class C fly ashes may contain lime contents higher than 10%.

Glass Fiber Reinforced Concrete, also known as GFRC or GRC, is a type of fiber reinforced concrete. Anti- Crack HD

Experimental Investigation on Properties of the concrete using

Fly Ash with Glass Fibre 1A.Khalid Ahmed Gour, 2K.M.Mohammad Sathik Ali, 3C.Sanjay, 4R.Srinivasan 1,2,3,4 UG Student, Department of Civil Engineering, Vel Tech, Chennai, INDIA



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(High Dispersion) is defined as an engineered AR glass chopped strand designed for mixing in concrete and all hydraulic mortars where uniform dispersion of the fibers reinforcement is needed. Glass fiber concretes are mainly used in exterior building facade panels and as architectural precast concrete. The composite panels are of recyclable and enhance building life and durability with resistance to corrosion, fire, UV light & temperature variations. It has been used for 40 years in more than 100 countries. It is used due to the Presence of Zirconium (16 18 % ) gives Alkali Resistant Properties to glass fibre.

There are many types of fibre , namely - Polyester Glass Fibre, Polypropylene Glass Fibre, Steel Glass Fibre, Alkali Resistant(AR) Glass Fibre. We have used AR glass fibre in this project.

II. FINDING FROM THE LITREATURE REVIEW

1. The author explains the effects of fly ash on concrete of

various concentrations with cement. It improves in the long-

term durability of concrete combined with ecological benefits.

This paper reports a comparative study on effects of concrete

properties with the replacement of fly ash [2].

2. The author aimed to investigate the physical, chemical and

mechanical properties of fly ash cement concrete. This paper

has shown that 30% of fly ash and 70% of cement has a

superior performance. It results in reduction in the cost of

materials and greenhouse gas emission [3].

3. The paper reports the experimental investigation result on

the effects of fly ash on strength development of mortar.

Cement was partially replaced with six percentages (10%,

20%, 30%, 40%, 50% and 60%) of class F fly ash by weight.

Compressive and tensile strength were determined at 3, 7, 14,

28, 60 and 90 days. Among the six fly ash mortars, the optimum amount of cement replacement in mortar is about

40%, which results 14% higher compressive strength and 8%

higher tensile strength as compared to OPC mortar [4].

4. GFRC has advantage of being light weight and reduces

overall construction cost. Here, glass fibre is used for

reinforcement instead of steel. It increases to an optimum

percentage of 1.5% by the weight of cement and further it

decreases in 2% of adding glass fibre [5]

5. The report aims to evaluate glass fiber on the properties of fresh and hardened self compacting concrete. The work

involves four mixes, the mix proportion of these mixes is (1:

1.75:2), and w/c ratio (0.4), super plasticizer of 5 % of cement,

limestone powder (100Kg /m3), and glass fiber (0, 1, 3, 5) %

of mixes volume respectively. Slump flow, L-Box and V-

funnel tests are to determine the workability of all mixes, the

values of slump flow are (710, 680, 655, 615)mm, the

compressive strength with average value of six specimens are

(47.3, 48.7, 51.3, 54.7) N/mm2 of 28 days and splitting tensile

strength with average values of six specimens are (4.1, 4.3,

4.6, 5.1) N/mm2 of 28 days. Flexural strength was tested with

average values of three specimens are (4.1, 4.3, 4.6, 5.1) N/mm2 of 28 days. for glass fiber ratio of (0, 1, 3, 5) %

respectively [5].

III. METHODOLOGY

Fig.1 Flow Chart Of The Detailed Methodology

A. MATERIAL USED

Cement (OPC 53 Grade Cement)

Fly Ash (Class F Type Fly Ash)

Water

Fine Aggregate (Sieve Less Than 4.75mm Till 0.15mm)

Coarse Aggregate (10mm To 20mm Size Aggregate)

Glass Fibre (AR)

B. REQUIREMENTS

Use Of OPC 53 Grade Cement

Mix Concrete Grade Of M30

Use Of 10mm And 20 mm Sieve Size Coarse Aggregate

Fly Ash percentage Of 30%, 35% And 40%

Glass Fibre percentage Of 0.5%, 1%, And 2%

Steel Mould Cube Size Of 150 X 150 X 150 mm

Steel Mould Cylinder Size Of 150 mm Diameter And 300 mm Height.

C. MATERIAL TESTING

Sieve Analysis for Fine Aggregate and Coarse Aggregate.(IS 2386)



9

20

25

30

35

CO

MP

RE

SS

EIV

E S

TR

EN

GT

H

(MP

a)

STD

CONCRETE

FLY ASH -

30%

FLYASH -

35%

FLY ASH -

40%

Specific Gravity of Fine Aggregate, Coarse Aggregate, Cement and Fly ash. (IS 2386)

Bulk Density. (IS 2386)

Water Absorption Test. (IS 2386)

C.1 TEST RESULTS

The fineness of fine aggregate = 2.61

The specific gravity of fine aggregate = 2.40

The specific gravity of coarse aggregate = 2.62

The specific gravity of fly ash aggregate = 2.35

The specific gravity of cement aggregate = 2.30

Water Absorption = 1.11%

D. MIX RATIO PROPOTION

The different mix proportions are given below:

Standard Concrete M30 Grade = 1:1.07: 2.26

M30 Grade with 30 % of fly ash = 1: 1.49: 3.15: 0.43

M30 Grade with 35 % of fly ash = 1: 1.60: 3.39: 0.54 M30 Grade with 40 % of fly ash = 1: 1.72: 3.65: 0.66

IV. RESULTS AND DISCUSSIONS

1. COMPRESSIVE STRENGTH

1.1 For various Concentration of Fly ash

Table.1 Compressive Strength For Different Mix Proportion

Fig. 2 Column Chart of Compressive Strength for Various

Concentration of Fly Ash

In the table 1, the compressive strength for all the specimens is

shown and in the column chart the average compressive strength is shown. Among the various concentration of the fly

ash i.e., 0%, 30%, 35%, 40%, the 0% of fly ash i.e., the

standard concrete attains average strength of 31.82 Mpa for a

curing process of 28 Days. There is a decrement seen of

9.24% in the fly ash content of 30% compared to standard

concrete. A increment of 4.36% seen in the compressive

strength of Fly ash content of 35 % , followed by a decrement

of 12% in the fly ash content of 40% compared to the standard

concrete. Therefore, the optimum percentage of fly ash is 35

%, and the corresponding average compressive strength

obtained is 31.85 Mpa.

TRAIL

FLY

ASH

%

COMPRESSIVE

STRENGTH

(MPa)

28 DAYS

AVERAGE

COMPRESSIVE

STRENGTH

(MPa)

1

0

30.66

30.52 2 30.32

3 30.66

1

30

28

27.70 2 27.11

3 28

1

35

32

31.85 2 31.55

3

32

1

40

27.56

26.81

2 26.67

3 26.22



10

0

1

2

3

4 STD

CYLINDER

FLY ASH

30%

FLY ASH

35%

Fig.4 Cracking of cube and corresponding reading

1.2 Compressive Strength for various Concentrations

of Glass Fibre with Optimum Fly ash Content

Table.2 Compressive Strength for Different Mix Proportion

Fig 5 Column Chart of Compressive Strength for Various

Concentrations of Glass Fibre

In the table 2, the compressive strength for all the specimens

is listed out and in the column chart the average compressive strength is shown. Among the various concentration of the

glass fiber i.e., 0.5%,1%,2%, keeping the fly ash content as

optimum ,the standard concrete attains average strength of

31.82 Mpa for a curing process of 28 Days. There is an

increment seen of 26.7% in the glass fiber content of 0.5%

compared to standard concrete. Again an increment of 36.4%

seen in the compressive strength of glass fiber content of 1 % ,

followed by a decrement of 5.34% in the glass fiber content of

2% compared to the standard concrete. Therefore, the

optimum percentage of glass fibre is 1%, and the

corresponding average compressive strength obtained is 41.63

Mpa.

2. SPLITTING TENSILE STRENGTH

2.1 Various Concentration Of Fly Ash

Table 3 Splitting Tensile Strength For Different Mix

Proportion

T

R

A

I

L

F

L

Y

A

S

H

%

GLASS

FIBRE

%

COMPRESSIVE

STRENGTH

(MPa)

28 DAYS

AVERAGE

COMPRESSIVE

STRENGTH

(MPa)

1

3

5

0.5

39.56

38.67 2 38.67

3 37.77

1

1

41.22

41.63

2 41.78

3 40.89

1

2

30.22

28.89 2 27.56

3 28.89

SPECIMEN

NO

F

L

Y

A

S

H

%

SPLITTING

TENSILE

STRENGTH

(MPa)

28 DAYS

AVERAGE

SPLITTING

TENSILE

STRENGTH

(MPa)

1

0

3.39

3.35 2 3.26

3 3.39

1

30

2.97

2.93 2 2.83

3 2.97

1

35

3.40

3.50 2 3.70

3 3.40

1

40

2.54

2.50 2 2.41

3 2.54

25

26

27

28

29

30

31

32

CO

MPR

ESS

EIV

E S

TRENG

TH

(M

Pa)

PERCENTAGE OF GLASS FIBRE

AVERAGE COMPRESSIVE STRENGTH

OF GLASS FIBRE

GLASS FIBRE

0.5%

GLASS FIBRE

1%

GLASS FIBRE

2%

Fig.3 Casting, Vibrating and curing of

Specimen



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Fig 6 Column Chart of Splitting Tensile Strength for Various

Concentration of Fly Ash

In the table 3, the Splitting tensile strength for all the

specimens is listed out and in the column chart the average compressive strength is shown. Among the various

concentration of the fly ash, the 0% of fly ash i.e., the standard

concrete attains average strength of 3.35 Mpa for a curing

process of 28 Days. There is a decrement seen of 12.54% in

the fly ash content of 30% compared to standard concrete. An

increment of 4.48% seen in the splitting tensile strength of fly

ash content of 35 % , followed by a decrement of 25.37% in

the fly ash content of 40% compared to the standard concrete.

Therefore, the optimum percentage of fly ash is 35%, and the

corresponding average splitting tensile strength obtained is 3.5

Mpa.

The various percentage of fly ash is illustrated in a line chart

and column chart with various concentrations of fly ash

replaced in cement content by its volume of 30%, 35% and

40% (of cement content).

The crack pattern and the splitting tensile strength is observed

and Figd below of Fig 7.

2.2. Splitting Tensile Strength for various Concentration of

Glass Fibre with Optimum Fly ash Content

Table.4 Splitting tensile Strength for Different Mix Proportion

Fig. 7 Cracking Of Cylinder And Corresponding Reading

Fig. 8 Column Chart Of Splitting Tensile Strength For Various

Concentrations Of Glass Fibre

In the table, the splitting tensile strength for all the specimens

is listed out and in the column chart the average tensile

strength is shown. Among the various concentration of the

glass fiber i.e., 0.5%, 1%, 2%, keeping the fly ash content as

optimum which is 35%, the standard concrete attains average

strength of 3.35 Mpa for a curing process of 28 Days. There is

an increment seen of 7.16% in the glass fiber content of 0.5%

compared to standard concrete. Again a increment of 19.7%

seen in the splitting tensile strength of glass fiber content of 1

% , followed by a decrement of 7.16% in the glass fiber

content of 2% compared to the standard concrete. Therefore, the optimum percentage of glass fibre is 1 %, and the

corresponding average splitting tensile strength obtained is

4.01 Mpa.

Fig. 9 Glass Fibre Texture In The Concrete

TRAIL

F

L

Y

A

S

H

%

GLASS

FIBRE

%

SPLITTING

TENSILE

STRENGTH

(MPa)

28 DAYS

AVERAGE

SPLITTING

TENSILE

STRENGTH

(MPa)

1

3

5

0.5

3.68

3.59 2 3.39

3 3.68

1

1

3.96

4.01 2 4.1

3 3.96

1

2

3.39

3.11 2 2.83

3 3.11



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V. CONCLUSION

Based on the investigation for various concentration of fly ash

and various concentration of glass fibre and the concrete cured

for 28 days , the following conclusions can drawn ,

1. The compressive strength found to be increasing at fly ash content of 35%, whereas in 30 % and 40%,

the strength found to be decreasing.

2. The increase in compressive strength is 4.36% compared to the conventional concrete.

3. The splitting tensile strength found to be increasing at fly ash content of 35%, whereas in 30 % and 40%,

the strength found to be decreasing.

4. The increased in splitting tensile strength is 5.07% compared to the conventional concrete.

5. The compressive strength found to be increasing at optimum content of fly ash 35% with glass fibre 1%,

whereas in 0.5 % and 2%, the strength found to be decreasing.

6. The increase in compressive strength is 36.4% compared to the conventional concrete.

7. The splitting tensile strength found to be increasing at optimum content of fly ash 35% with glass fibre 1%,

whereas in 0.5 % and 2%, the strength found to be

decreasing.

8. The increase in splitting tensile strength is 19.7% compared to the conventional concrete.

REFERENCES

[1] CONCRETE TECHNOLOGY book by M.S. SHETTY, S.Chand and Company limited , New delhi.

[2] C.Marthong, T.P.Agrawal (2012)A Project on effect of fly ash additive on concrete properties, Ijera., Vol 2 Issue.4, pp.1986-1991.

[3] Tomas U. Ganiron A Project on analysis of fly ash cement concrete, International Journal of Advanced Science and Technology, Vol.60, pp.33-44.

[4] Md. Moinul Islam And Md. Saiful Islam (2010) Strength Behaviour of mortar using fly ash as partial replacement of cement, Concrete Research Letters., Vol 1 (3), pp.98-105.

[5] Avinash Gornale (2012) ,A journal on strength aspects of glass fibre reinforced concrete, Vol 3, Issue 7, pp.1-5.

[6] Mohammed Karem Abd, (2013) Evaluation of using glass fiber on properties of self-compacting concrete, Journal of Kerbala University , Vol. 11, pp.16-25.

[7] IS 10262-2009 and IS 456-2000 Indian Standard Code Book.

iisrt khalid ahmed gour (civil)

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