Experimental Investigation On Silica Fume And Fly Ash ... - iJournals

iJournals: International Journal of Software & Hardware Research in Engineering

ISSN-2347-9698 Volume 8 Issue 4 April 2020

Sharukh Qureshi ,JIji M Thomas,Pushpendra Kumar Kushwaha ,Vol 8 Issue 4, pp 20-29, April 2020

Experimental Investigation On Silica Fume

And Fly Ash As A Partial Replacement Of

Cement For M-25 Concrete

Sharukh Qureshi1 ,JIji M Thomas

2,Pushpendra Kumar Kushwaha

3

1M.Tech Research Scholar Civil Department RKDF College of Engineering, Bhopal

2Assistant Professor Civil Department RKDF college of Engineering, Bhopal,

3HOD of Civil Department RKDF College of Engineering, Bhopal

Abstract— In the present days concrete are the most adaptable structure materials because it can be designed to

survive the harshest environments while taking on the most encouraging forms. In the present scenario most

concrete mixture contains additional cementitious material which forms element of the cementitious element. The

major benefit of supplementary cementitious material is their ability to return certain amount of cement and still

capable to present cementitious property, as a result reducing the cost of using Portland cement. The waste

materials which can be used as additional cementitious material like fly ash, silica fume, blast furnace, steel slag

etc. From all these waste material the most successful cementitious material is silica fume & fly ash because it

improves the strength and durability of concrete to such level that recent design rules identify for the addition of

silica fume for design of high strength concrete. Silica fume is also known as micro silica; it is used as an

artificial pozzolanic super plasticizer. Now days the high strength and high performance concrete is extensively

used in much civil engineering structure. To reduce the amount of cement in concrete supplementary material are

used. Silica fume & fly ash is most popular material used in the concrete to improve its compressive, flexural, split

tensile strength and also increase its durability. For this purpose silica fume & fly ash is replaced by 0%, 5%,

7.5%, 12.5%, 15%, 20% & 25% by the weight of cement. Water binder ratio is taken 0.42 for M-25 grade of

concrete. Various tests were conducted in the research which showed the results of the same percentage at the

different of 0% 5%, 7.5%, 12.5%, 15%, 20% & 25% for the time period of 7, 14, and 28 days curing as a

substitution of cement by micro silica on compressive strength, flexural strength, split tensile strength. The results

show the maximum increase in strength of concrete occurred when 15% cement replacement was done with silica

fume. The optimum percentage of adding fly ash was determined to be 20% which showed the maximum

improvement in compressive strength, flexural strength & split tensile strength

Keywords— compressive strength, flexural strength, split tensile strength, silica Fume, Fly ash

I. INTRODUCTION Concrete is a most commonly used building material which is a mixture of cement, sand, coarse aggregate and

water. It is used for construction of multi-storey buildings, dams, road pavement, tanks, offshore structures, canal

lining. The method of selecting appropriate ingredients of concrete and determining their relative amount with the

intention of producing a concrete of the necessary strength durability and workability as efficiently as possible is

termed the concrete mix design. The compressive strength of harden concrete is commonly considered to be an

index of its extra properties depends upon a lot of factors e.g. worth and amount of cement water and aggregates

batching and mixing placing compaction and curing. The cost of concrete prepared by the cost of materials plant

and labour the variation in the cost of material begin from the information that the cement is numerous times



© 2020, iJournals All Rights Reserved www.ijournals.in

Page 21

costly than the aggregates thus the intent is to produce a mix as feasible from the practical point of view the rich

mixes may lead to high shrinkage and crack in the structural concrete and to development of high heat of

hydration in mass concrete which may cause cracking. The genuine cost of concrete is related to cost of materials

essential for produce a minimum mean strength called characteristic strength that is specific by designer of the

structures.

II. REVIEW OF LITERATURE

{1} K. Perumal et.al [2004] studied on the performance of high performance concrete trial mixes having

different replacement levels of cement with silica fume. Compressive strengths of 60 MPa, 70 MPa and 110 MPa

at 28days were obtained by using 10 percent replacement of cement by Silica fume. The results also show that the

SF concretepossesses superior durability properties. Cement replacement level of 10 percent with SF in M60,

M70 and M110 grades of HPC mixes is found to be the optimum level to achieve high values of compressive

strength, split tensile strength, flexural strength.

{2} Prof. Vishal S. Ghutke, et.al [2011] determined the optimum replacement percentages which may be used

properly under the Indian conditions. It has been seen that when cement is replaced with silica fume compressive

strength increases up to definite percentage (10% replacement of cement by silica fume). However higher

replacement of cement with silica fume gives lesser strength. The result of Silica fume on various properties of

Concrete is evaluated. They concluded that increase in w/cm ratio strength of concrete decreases.

{3} Verma Ajay et.al [2012] performed an investigation on the properties of materials crystalline and non-

crystalline. Micro silica is especially fine non crystalline material. In the investigation they used silica fume as a

non-natural pozzolana. On adding 0%, 5%, 10%, 15% of silica fume by weight of cement in concrete. Silica

fume improves concrete through two mechanisms: pozzolonic effect and micro filler effect. Silica fume increases

the strength of concrete more up to 25%. Silica fume is a material which can be an explanation of Air Pollution

(this is a byproduct of some industries). The use of micro silica with concrete may be decrease the air pollution

{4} N. K. Amudhavalli, Jeena Mathew [2012] reviewed on the study of M35 grade concrete with partial

substitute of cement by micro silica with percentage of 5, 10, 15 and 20%. It gives a detailed experimental study

on Compressive strength, split tensile strength flexural strength on age of 7 and 28 days. Test results shows that

use of micro silica in concrete have enhanced the performance of concrete in strength as well as in durability

feature. The optimum micro silica replacement percentage for obtaining highest 28- days strength of concrete

range from 10 to 20 %. Cement substitute up to 10% with silica fume leads to enhance in compressive strength of

concrete designed for M30 grade.

{5} Dilip Kumar Singha Roy et.al [2012] worked on the strength parameters of concrete made with partial

replacement of cement by SF. Compressive strength, Flexural strength, Splitting Tensile strength have been

determined for different mix up combinations of materials and these values are compared with the relatedvalues

of conventional concrete. From the study it has been observed that maximum compressive strength (both cube

and cylinder) is noted for 10% substitute of cement with micro silica and the values are higher (by 19.6% and

16.82% respectively) than those of the normal concrete (for cube and cylinder) whereas split tensile strength and

flexural strength of the SF concrete are increased by about 38.58% and 21.13% respectively over those (2.6

N/mm2 and 4.07 N/mm2 respectively) of the normal concrete when 10% of cement is replaced by SF.




Page 22

III. MATERIALS & METHODOLOGY

General

The use of Supplementary cementious material such fly ash, slag and silica Fume improve in forced concrete

corrosion performance, While decreasing cost and reducing environmental impact compared to ordinary Portland

cement.

Material

Cement:- In the study ordinary Portland cement is used to prepare the M25 grade concrete. As we know that

cement is main component of concrete which is used to bind the fine and coarse aggregate. Cement is also most

costly component of concrete which affect the overall cost of concrete. So we try to reduce the cement

consumption in concrete by replacing it with silica fume and fly ash.

Silica Fume:-

Silica fume is a by product from the manufacturing of ferrosilicon alloy and silicon metal. Silica fume is an

industrial waste which is smoke sediment deposited during the furnace operations. It may be a good replacement

of cement in concrete due to its very reactive pozzolanic nature.

Fly Ash:-

Fly ash is also industrial waste form the thermal power plant. It is a good supplementary cementitious material

which is used in the concrete to reduce the cement consumption which reduces the overall coast of the concrete.

Aggregate:-

Sand is a fine aggregate which is used to fill the voids between coarse aggregate also to improve the workability

of concrete. Particle size range of sand is from 4.75 mm to 150 micron. In this study river sand is used due to its

easy availability and pure condition.

Coarse aggregates are the main body of concrete is occupy 60-70% volume in concrete. Generally coarse

aggregate of size 10 mm to 40 is used in concrete depending on the use of concrete. Also aggregate is the main

load bearing component of concrete.

Testing of Concrete

Slump Cone Test

Compressive Strength Test

Flexural Strength Test

Split Tensile Strength Test

Formulation of Research

In this stage of work cement is partially replaced by Silica Fume in different percentages as shown in the table

below. 7 batches are prepared in different proportions including conventional concrete mix (Cement as binder,

Sand as fine aggregates & Natural Coarse Aggregates). Cubes and beams are casted for determining compressive

and flexural strengths respectively at 7, 14 and 28days.




Page 23

Table No. Formulation of work

Batch

Mix Cement% Silica Fume% Fly Ash% Sand%

Natural Coarse

Aggregates%

1 100 ----- ----- 100 100

2 75 25 25 100 100

3 80 20 20 100 100

4 85 15 15 100 100

5 87.5 12.5 12.5 100 100

6 92.5 7.5 7.5 100 100

7 95 5 5 100 100

IV. RESULTS & DISCUSSION

Compressive Strength

In the Compressive strength test is performed on 3 cubes of each batch mix for 7 days, 14 days & 28 days. There are

7 batch mixes and each one having 9 cubes of these 9 cubes, 3 cubes are tested for 7 days, 14 days & 28 days each.

An average of 3 values as tabulated in subhead results, are considered for discussions.

0

5

10

15

20

25

Co

mp

ress

ive

Str

en

gth

(N

/mm

2)

Replacement Percentage

compressive strength for 7 Days

SILICA FUME

FLY ASH

Graph : Compressive strength of silica fume and fly as for 7 days




Page 24

0

5

10

15

20

25

Co

mp

ress

ive

Str

eng

th (

N/m

m2)


compressive strength for 14 Days

SILICA FUME

FLY ASH


0

5

10

15

20

25

30

Com

pre

ssiv

e S

tren

gth

(N

/mm

2)


compressive strength for 28 days

SILICA FUME

FLY ASH


As shown in the graph: (7 days strength), when cement is partially replaced 15% by SF, compressive strength is

increased by 27.68%. Afterwards when addition of % of SF is replaced, strength starts decreasing, a minimum

strength is achieved.

When graph: (14 days strength) is analyzed, 15 % replacement of silica fume gives 24.5% more strength when

compared with conventional concrete. For 28 days strength in graph: 5.3 show an increment of 26.85% of strength

of 15% replacement of silica fume as compared with conventional concrete. Again strength is decreased when

addition of percentage of silica fume As discussed here, it can be said that an increment in compressive strength of

15 % replacement of silica fume gives 27% strength is achieved as compared with conventional concrete mix

i.e.Mix-01.




Page 25

Flexural Strength

Flexural strength test is performed on 2 beams of each batch mix for 7 days, 14 days & 28 days. There are 7 batch

mixes and each one having 6 beams. Of these 6 beams, 2 beams are tested for 7 days, 14 days & 28 days each. An

average of 2 values as tabulated in subhead results, are considered for discussions.

0

1

2

3

4

5

Fle

xu

rsl

Str

ength

(N

/mm

2)


Flexural Strength Result for 7 days

SILICA FUME

FLY ASH

Graph : Flexural strength of silica fume and fly as for 7 days

0

1

2

3

4

5

6

Fle

xu

rsl

Str

ength

(N

/mm

2)



SILICA FUME

FLY ASH





Page 26

0

1

2

3

4

5

6

7

Fle

xu

rsl

Str

ength

(N

/mm

2)



SILICA FUME

FLY ASH


As shown in the graph: (7 days strength), when cement is partially replaced 20% by SF i.e. Mix-06, flexural strength

is increased by 20%. Afterwards when % of SF is increased the strength starts decreasing

When graph:(14 days strength) is analyzed, 20% replacement of silica gives

25.39%moreflexuralstrengthwhencomparedwithnormalconcrete.Herealso,when % of SF is increased, strength starts

decreasing.

28 days strength in graph: shows an increment of 22.10% of strength of 20% replacement of silica fume as compared

with conventional concrete. Again strength is decreased when % of silica fume is increased.

As discussed here, it can be said that an increment in compressive strength of 20% replacement of silica fume nearly

25% is achieved as compared with conventional concrete mix.

Split Tensile Strength

Split Tensile Strength is performed on 2 cylinders of each batch mix for 7 days, 14 days & 28 days. There are 7 batch

mixes and each one having 6 cylinders. Of these 6 cylinders, 2 cylinders are tested for 7 days, 14 days & 28 days

each. An average of 2 values as tabulated in subhead results, are considered for discussions.

0

2

4

6

8

Ten

sile

Str

ength

(N

/mm

2)


Split tensile strength at 7 days

SILICA FUME

FLY ASH

Graph : Split tensile strength of silica fume and fly as for 7 days




Page 27

01234567

Ten

sile

Str

eng

th (

N/m

m2)



SILICA FUME

FLY ASH


01234567

Ten

sile

Str

eng

th (

N/m

m2)



SILICA FUME

FLY ASH


As shown in the graph: (7 days strength), when cement is partially replaced 15% by SF i.e., Split Tensile strength is

increased by 38%. Afterwards when % of SF is increased the strength starts decreasing

When graph: (14 days strength) is analyzed, 15% replacement of silica gives 42.39% more Split Tensile strength

when compared with normal concrete. Here also, when % of SF is increased, strength starts decreasing.

28 days strength in graph: Shows and increment of 45.58% of strength of 15% replacement of silica fume as

compared with conventional concrete. Again strength is decreased when % of silica fume is increased.

As discussed here, it can be said that an increment in compressive strength of 15% replacement of silica fume nearly

45% is achieved as compared with conventional concrete mix.

V. CONCLUSIONS

General

Silica Fume :- Compressive strength, Flexural strength, Split tensile strength and Durability test of concrete Mixes

made with and without silica fume has been determined at 7, 14, & 28 days of curing. The strength gained has been




Page 28

determined of silica fume added concrete with addition of 5%, 7.5%, 12.5% 15%, 20% & 25% for M25 grade as a

partial replacement of cement in conventional concrete. From the results it is conclude that the silica fume is a

superior replacement of cement. The rate of strength increase in silica fume concrete is high. After performing all the

tests and analyzing their result, the following conclusions have been derived:

o The results achieved from the existing study shows that silica fume is great potential for the utilization in

concrete as replacement of cement.

o Workability of concrete decreases as proportion of silica fume increases.

o Maximum compressive strength was observed when silica fume replacement is about 15%.

o Maximum split tensile strength was observed when silica fume replacement is about 20%.

o Maximum flexural strength was observed when silica fume replacement is about 15%.

Fly ash :- Compressive strength, Split tensile strength of concrete Mixes made with and without fly ash has been

determined at 7, 14, & 28 days of curing. The strength gained has been determined of fly ash added concrete with

addition of 0%, 5%, 7.5%, 12.50 % 15 % 20% and 25 %, for M25 grade as a partial replacement of cement in

conventional concrete. From the results it is conclude that the Fly Ash is a superior replacement of cement.

o The Results achieved from the Existing Study Shows that Fly Ash Great Potential for the Utilization In

concrete As Replacement Of cement.

o Workability of Concrete Decreases as Proportion of Fly Ash increases.

o Maximum Compressive Strength Was Observed When Fly Ash Replacement Is About 20%.

o Maximum Split Tensile Strength Was Observed When Fly Ash Replacement Is About 20% Maximum

Flexural Strength Was Observed When Fly Ash Replacement Is About15%.References

VI. REFERENCES

{1} K. Perumal R. Sundararajan, Effect of partial replacement of cement with silica fume on the strength and

durability characteristics of high performance concrete 29th conference on our world in concrete & structures: 25 -

26 August 2004, Singapore Article Online Id: 100029050.

{2} Prof. Vishal S. Ghutke, Prof. PranitaS.Bhandari, Influence of silica fume on concrete IOSR Journal of

Mechanical and Civil Engineering(IOSR-JMCE) E-ISSN: 2278-1684, p-ISSN: 2320-334.

{3}Verma Ajay, ChandakRajeevandYadav R.K., Effect of Micro Silica on The Strength of Concrete with Ordinary

Portland Cement, Received 2nd June 2012, revised 10thJune 2012, accepted 15th June 2012, ISSN 2278 – 9472 Vol.

1(3), 1-4, Sept. (2012) Res. J. EngineeringScience.

{4} N. K. Amudhavalli, Jeena Mathew,Effect of Silica Fume on Strength and Durability Parameters of

Concrete,International Journal of Engineering Sciences & Emerging Technologies, August 2012. ISSN: 2231 – 6604

Volume3, Issue 1, pp: 28-35 ©IJESET.

{5} Dilip Kumar Singha Roy, AmitavaSil Effect of Partial Replacement of Cement by Silica Fume on Hardened

Concrete International Journal of Emerging Technology and Advanced Engineering (ISSN 2250-2459, Volume 2,

Issue 8, August2012).

{6} VikasSrivastava, V.C. Agarwal and Rakesh Kumar Effect of Silica fume on mechanical properties of Concrete J.

Acad. Indus. Res. Vol. 1(4) September 2012 ISSN:2278-5213.

{7} Faseyemi Victor Ajileye, Investigations on Micro silica (Silica Fume) As Partial Cement Replacement in

Concrete Global Journal of researches in engineering Civil And Structural engineering Volume 12 Issue 1 Version

1.0 January 2012 Type: Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc.

(USA) Online ISSN: 2249-4596 & Print ISSN:0975-5861

{8}DebabrataPradhan, D. Dutt, Influence of Silica Fume on Normal Concrete,




Page 29

DebabrataPradhanetal.Int.JournalofEngineeringResearchandApplicationsVol.3, Issue 5, Sep-Oct 2013, pp.79-82.

{9}Pratik Patel Dr. Indrajit N. Patel Effect of Partial Replacement of Cement with Silica Fume and Cellulose Fibre

on Workability & Compressive Strength of High Performance Concrete Volume : 3 | Issue : 7 | July 2013 | ISSN -

2249-555X.

{10} I. B. Muhit1, S. S. Ahmed2, M. M. Amin1 and M. T. Raihan1.Effects of Silica Fume and Fly Ash as Partial

Replacement of Cement on Water Permeability and Strength of High Performance Concrete Proc. of Int. Conf. on

Advances in Civil Engineering, AETACE 1Department of Civil Engineering, Chittagong University of Engineering

& Technology, Chittagong-4349,Bangladesh.

{11}Khalid BattalNajimet.al. Workability and mechanical properties of crumb-rubber concrete, Proceedings of the

Institution of Civil Engineers Construction Materials, February 2013, Volume 166 Issue CM1.

{12}NasratullahAmarkhail. Effects Of Silica Fume On Properties Of High-Strength Concrete, International Journal

of Technical Research and Applications e-ISSN: 2320-8163 Special Issue 32 (September, 2015), PP. 13-19.

{13} Nadeem Pasha1 Mohammed Muqueem Ahmed2 Mohammed Azeemuddin3 Shaikh Minhajuddin4 Waseem

Ali5. Study on Strength Characteristics of Silica Fume and Fly Ash as Partial Replacement of Cement. IJSRD -

International Journal for Scientific Research & Development| Vol. 3, Issue 02, 2015 | ISSN (online): 2321-0613.

{14} AtishayLahri, Dr. Savita Dixit. Alternatives to Cement in Concrete – A Review, International Journal of

Scientific & Engineering Research, Volume 6, Issue 10, October-2015, ISSN 2229-5518.

{15} BelachewAsteray, Walter Oyawa et.al. Experimental Investigation on Compressive Strength of Recycled

Reactive Powder Concrete Containing Glass Powder and Rice Husk Ash, Journal of Civil Engineering Research

2017, 7(4): 124-129.

IS –Code:-

IS -10262-2009 (Design of Concrete Mix Design)

IS-456-2000

Experimental Investigation On Silica Fume And Fly Ash ... - iJournals

Documents