An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete

IJSRD - International Journal for Scientific Research & Development| Vol. 2, Issue 07, 2014 | ISSN (online): 2321-0613

An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete Md Asif Ahmed1 Prof. Syed Arafath2 1 PG Student 1,2 Department of Civil Engineering 1,2 K.B.N Engineering College, Gulbarga, Karnataka, India.

Abstract— The present investigation carried out on concrete due to the effect of silica fume with and without steel fibers on ordinary Portland cement. In this study we used concrete mixes with Silica Fume of 0%, 4%, 8%and 12%, with addition of crimped steel fibers of diameter 0.5 mm Ø with a aspect ratio of 60, at various percentages as 0%, 0.5 %, 1.0 % and 1.5 % by the volume of concrete on M30 grade of concrete. The effect of mineral admixture (silica fume) as cement replacement material with and without steel fibers on mechanical properties were analyzed and compared with normal concrete. In comparison, with normal concrete the replacement of 4%, 8% and12% cement by silica fume showed 7.27%, 15.64%, 12.79% increase in compressive strength in 28 days of curing. . In comparison, with normal concrete the replacement of 4%, 8% and12% cement by silica fume showed 6.21%, 6.52%,6.36% increase in split tensile strength in 28 days of curing. In comparison, with normal concrete the replacement of 4%, 8% and12% cement by silica fume showed 14.59%,20.43%,19.70% increase in flexural strength in 28 days of curing. Present study aimed to conclusion that, in comparison with 0%, 4%, 8%and 12% of silica fume and 0%, 0.5 %, 1.0 % and 1.5 % steel fibers ,8% silica fume and 1.5% steel fibers was recognized as the best for both economical and strength aspects.

Keywords: Silica Fume, Steel Fibre, Compressive strength, Flexural strength, Split Tensile Strenght, SFRC I. INTRODUCTION A. Silica Fume in Concrete The American concrete institute (ACI) defines silica fume as a every fine non-crystalline silica produced in electric are furnaces as a byproduct of production off elemental silicon or alloys containing silicon”. Silica fume is also known as micro silica fume is also known as micro silica, condensed silica fume. Volatized silica or silica dust. It is usually a grey colored powder, somewhat similar to Portland cement or some fly ashes. It can exhibit both pozzolanic and cementitious properties. Silica fume has been recognized as a pozzolanic admixture that is effective in enhancing the mechanical properties to a great extent. Addition of silica fume to concrete improves the durability of concrete and also in protecting the embedded steel from corrosion.

B. Steel Fibre in Concrete Plain concrete possesses a very low tensile strength, limited ductility and little resistance to cracking. Internal micro cracks are inherently present in the concrete and its poor tensile strength is due to the propagation of such micro cracks eventually leading to brittle fracture of the concrete.

It has been recognized that the addition of small closely spaced and uniformly dispersed fibers to the concrete would act as crack arrester and would substantially improve is compressive improve its compressive and flexural strength properties. This type of concrete is known as fiber

reinforced concrete. .Fibre reinforced concrete can be defined as a composite material consisting of mixtures of cement mortar or concrete and discontinuous, discrete, uniformly dispersed suitable fibers. Continuous meshes, woven fabrics and long wires or rods are not considered to be discrete fibers.

II. LITERATURE REVIEW A. Pawade Prashant, Y, Nagarnaik P.B. and Pande A.M Have conducted experiment on Influence of Silica fume in enhancement of compressive strength, flexural strength of steel fibers concrete and their relationship. They investigated on concrete due to the effect of silica fume with and without steel fibers on Portland Pozzolana cement. In this study we used concrete mixes with Silica Fume of 0% 4% 8% and 12% with addition of crimped steel fibers of two diameters 0.5mm  and 1.0mm  with a constant aspect ratio of 60. at varios percentages as 0% 0.5 %1.0% and 1.5% by the volume of concrete on M30 grade of concrete. In comparison, with control concrete the replacement of 4%, 8%, 12% cement by silica fume showed 7.46% 11.17%, 11.91% increase in compressive strength at 28 days of curing. The optimum combined effect at 8% silica fume and 1.5% steel fiber with normal concrete the maximum compressive strength increase at 0.5 mm  and 1.0 mm  steel fiber at 28 days of curing were 15.38% and 18.69% the maximum flexural strength increase were 17.13% and 24.02%. the combined effect of silica fume at 4% and 12% with steel fiber at 0.5% 1.0% & 1.5^ of both diameters 0.5 mm  and 1.0 mm  at different ages of curing are presented.[1] B. H kasthuda. B. Hamaneh and N. Shatarat have conducted experiment on the effects of silica fume on tensile, compressive and flexure strengths on high strength lightweight concrete. They carried out by replacing cement with different percentage of silica fume at different constant waller-binder ratio keeping other mix design variables constant. The silica fume was replaced by 0%, 5%, 10%, 20% and 25% for a water-binder ratios ranging from 0/26 to 0/42. for all mixes, split tensile, compressive and flexure strengths were determined at 28 days. The results showed that the tensile, compressive and flexure strengths increased with silica fume incorporation but the optimum replacement percentage is not constant because it depends on the watercementitious material (w/cm) ratio of the ix. Based on the results, a relationshi0p- between split tensile, compressive

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An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete (IJSRD/Vol. 2/Issue 07/2014/080)

and flexure strengths of silica fume concrete was developed using statistical methods.[2] III. EXPERIMENTAL PROGRAMME A. Materials 1) Cement Cement in general can be defined as a material which posses’ very good adhesive and cohesive properties which make it possible to bond with other material to form compact mass. As Shown in table 1 & 2.

Sl. Chart Properties No. Result 1 Specific Gravity 3.15 Setting time in minutes 1. Initial setting time 130min.

2 195min.

2. Final setting time

1.

3

Soundness :

By Le Chatrlier mould 2. By Autoclave

0.5mm 0.0936%

Finesses (specific surface) 303m2/kg Normal consistency 29.7% Compressive Strength 1.

3 days 42.3Mpa 2.

7 days 51.6Mpa 71.3Mpa 3.

28 days Table 1: Physical Properties of Opc

4 5 6

Sl. No.

Properties

Chart Result

1

Lime Saturation Factor(L.S.F)

0.92

Alumina Iron ratio

1.16

2 3

Loss on Ignition (LOI)

1.29%

4

Insoluble Residue(I.R.)

0.84%

5 6

Sulphuric Anhydride(SO3) Magnesia (MgO)

2.03% 1.16%

7

Alkalies

0.46%

8

Chlorides

0.0162%

Table 2: Chemical Properties of OPC 2) Silica Fume Silica fume is also referred to as microsilica or condensed silica fume, but the term ‘silica fume’ has become generally accepted. It is a by-product of the manufacture of silicon and ferrosilicon alloys from high-purity quartz and coal in a submerged-arc electric furnace. The escaping gaseous SiO oxidizes and condenses in the form of extremely fine spherical form of amorphous silica (SiO2); hence, the name silica fume. Physical & chemical properties as shown in table 3 & 4.

Particle size (Typical)

< 4 x 10-6 in

Specific Gravity

2.2

Surface area

60000 to 150000 ft2/lb

Characteristics Result

(%by mass)

Specifications

SiO2

% min 85.0

88.7

Moisture content

% max 3.0

0.7

+Loss on ignition 975c

% max 6.0

1.8

Carbon

% max 2.5

0.9

>45 micron

% max 10

0.2

Bulk density

500-700 Kg/m3

670

Tables 4: Chemical properties of silica fume 3) Steel Fibres A varying volume fraction i.e., 0.50%, 0.1% & 1.5% of fibres are used in this investigation. In this present investigation, the fibres used are round crimped steel fibres of diameter 0.5 mm and length 30mm (aspect ratio 80). The steel fibres are uniformly dispersed inside the entire mass of concrete.

4) Superplasticizers Super plasticizers constitute a relatively new category and improved version of plasticizer. Only thing is that the superplastiziers are more powerful as dispersing agents and they are high range water reduce. It is the use of superplastizier which has made it possible to use W/c as low as 0.25 or even lower and yet to make flowing concrete to obtain strength of the order 120 Mpa or more.

5) Fine Aggregate (FA) The aggregate which is passing through 4.75 mm sieve is known as fine aggregate. Locally available river sand which is free from organic impurities is used. Sand passing through 4.75mm sieve and retained on 150 micron IS sieve is used in this investigation.

For the casting, locally available river-sand, free from silt and organic matters was procured and used. The particle size of fine aggregate used in this study was such a way that it passed through 4.75mm sieve conforming to zone II of IS: 383-1970.

Properties of Fine Aggregate: Fineness modulus = 288.86 / 100 = 2.88 Specific gravity = 2.65 Water absorption = 1% Silt or clay content = 0.5% Bulk density = 1700 kg/m3 Grading = well graded (zone II) 6) Coarse Aggregate (CA) The coarse aggregate used in the investigation is 20mm down size crushed aggregate and angular in shape.

Properties of coarse aggregate: Fineness modulus = 612.40 / 100 = 6.12 Specific gravity = 2.70 Water absorption = 0.5% Impact value = 11.76% Bulk density = 1440 kg/m3 7) Water (IS 456–2000) Water used for both mixing and curing should be free from injurious amount of deleterious materials. Potable water is generally considered satisfactory for mixing and curing concrete. In the present work potable tap water was used.

Table 3: Physical properties of silica fume

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353

An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete (IJSRD/Vol. 2/Issue 07/2014/080)

B. casting & curing For each mix the standard size of (150mm x 150 mm x 150 mm) cube moulds, standard size of (100mm dia x 200mm height) cylinder moulds, standard size (100mm x 100 mm x 500 mm) prisms, modal RC beams of size (700mmx150mmx150mm) are casted. Cube, cylinder, prism and beam moulds are made up of cast iron for casting.

Before pouring the fresh concrete into these moulds, an engine oil is applied in thin layers to the inner surfaces of moulds in order to prevent the sticking of concrete to mould.

These specimens are allowed to set in the mould for 24 hours, after 24 hours these specimens are de-moulded and were kept under wet conditions by immersing them in water continuously for 7 and 28 days for cubes & Cylinders, 28 days for prisms, beams.

IV. RESULTS & DISCUSSIONS A. workability 1) Slump Cone Test and Compaction Factor Test This is a test used extensively in site work all over the work.

The slump test does not measure the workability of concrete although ACI 116R – 90 describes it as a measure of consistency, but the test is very useful in detecting variations in the uniformity of a mix of given nominal proportions.

2) Compaction Factor Test The degree of compaction, called the compaction factor, is measured by the density ratio i.e., the ratio of the density actually achieved in the test to the density of the same concrete fully compacted Specimen type Slump Compaction M30 Grade Concert (mm) Factor N.F

62

0.90

SF – 4%(B1)

50

0.89

SF – 8%(B2)

41

0.82

SF– 12%(B3)

35

0.74

Table 5: Results of Slump Cone Test and Compaction Factor Test B. Hardened Concrete 150 mm cube specimens and 100 mm x 200 mm cylinder specimens and 100mm x 100mm x 500 prism specimen were used for obtaining the compressive strength and split tensile strength and flexural strength respectively of concrete as per IS specification.

C. Tests for Compressive Strength The compressive strength of concrete for cubes, all mixes at 7 and 28 days of curing is presented in table 11. Only 3 cubes were casted for various percentage replacements of cement by SF. The compressive strength increases significantly due to addition of silica fume compared with normal concrete. The maximum increase in compressive strength was 15.63% at 28 days of curing for 8% of silica fume replaced by OPC cement. The compressive strength increases with the addition of steel fiber was marginal as compared with silica fume concrete.

D. Tests for split tensile strength The split tensile strength of concrete for cylinders, all mixes at 7 and 28 days of curing is presented in table 12.Only 3 cylinders were casted for various percentage replacements

of cement by SF. The split tensile strength increases with the addition of silica fume significantly compared with normal concrete. The maximum increase in split tensile strength was 6.52% at 28 days of curing for 8% of silica fume replaced by OPC cement. The split tensile strength increases with the addition of steel fiber was marginal as compared with silica fume concrete.

E. Tests for Flexural Strength The flexural strength of concrete for prisms, all mixes at 28 days of curing is presented in table 13. Only 3 prisms were casted for various percentage replacements of cement by SF. The flexural strength increases with the addition of steel fibers with 8% silica fume then normal concrete. The maximum increase in flexural strength was upto 26.76% and 29.99% and 33.09% at 28 days of curing at 0.5%, 1% and 1.5% of steel fibers. The flexural strength increases with the addition of silica fume was marginal as compared with steel fiber concrete.

A) WITHOUT SILICA FUME & STEEL FIBERS (Normal Concrete)

Mix SIN O

Ste el

Sili ca

design ation

7 days

Avg comp strg @ 7days N/mm

28 days

2

0%

0%

C1

27.64

C2

26.7

C3

27.72

Avg comp strg @ 28da ys N/m m2

38.72 27.12

39.00

39.07

39.50

Table 6: compressive strength test results at 7 and 28 days for CVC SIN 4% Avg Avg Steel Fiber O SilicaFume Com Com p p Dia 7day 28da @7 @28 &leng th

N/m m2

N/m m2

C 1

30.75

42.88

C 2

30.10

41.56

C 3

29.45

41.30

C 1

32.24

43.24

C

31.9

43.65

Days in N/m m2

30.10

41.91

32.28

43.14

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354

0.5mm 0%

ø &

ys

Days in N/m m2

1

2

s Vf (%)

0.5 %

An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete (IJSRD/Vol. 2/Issue 07/2014/080)

2

30 mm 3

1%

4 1.5 %

2

C 3

32.7

42.53

C 1

33.5

43.78

C 2

33.72

44.81

C 3

35.4

C 1

36.95

C 3

34.21

43.95

Avg SIN O

Steel Fiber

&lengt h

47.4

C 3

37.82

46.3

37.32

46.83

8% SilicaFume

Steel Fiber Dia &leng th

7day s Vf (%)

N/m m2 C 1

1

0%

0.5mm 2 ø &

0.5 %

3 30 mm 1%

4 1.5 %

28da ys N/m m2

34.4

45.67

C 2

33.64

44..5 6

C 3

34.80

C 1

36.27

47.23

C 2

35.46

48.56

C 3

36.86

48.18

C 1

37.83

48.80

7days Vf (%)

1

Table 7: compressive strength test results at 7 and 28 days of age for 4% of Silica Fume with steel fiber of 0.5 mm Ø at 0, 0.5, 1.0 and1.5% SIN O

12% SilicaFume

Dia

46.78

37.2

0%

47.90

C 3

38.53

48.64

C 1

40.65

C

41.18

C 1

32.75

44.26

C 2

32.43

43.17

C 3

31.10

44.78

C 1

33.53

45.73

C 2

34.14

44.68

Com p

@7

@28

ø

days

days

&

C 3

34.27

45.81

N/m m2

N/m m2

C 1

36.13

46.21

30 mm

C 2

35.78

47.25

C 3

35.90

46.89

C 1

38.23

47.15

C 2

38.10

46.10

C 3

37.95

46.70

2

0.5mm

0.5 %

3

1%

34.28

45.18 4

36.19

47.99

Comp @28

@7

days

days N/mm

N/mm

2

2

32.10

44.07

33.98

45.41

35.94

46.78

38.09

46.65

2

Com p

Table 9: compressive strength test results at 7 and 28 days of age for 12% of Silica Fume with steel fiber of 0.5 mm Ø at 0, 0.5, 1.0 and1.5% A) WITHOUT SILICA FUME & STEEL FIBERS (Normal Concrete)

38.42

48.45

SINO

S t e e l

Sili ca

1

48.90 2

49.23

2

Avg Comp

N/mm

Avg

1.5 %

38.90

N/mm

28day s

Avg

45.30

C 2

48.57

Table 8: compressive strength test results at 7 and 28 days of age for 8% of Silica Fume with steel fiber of 0.5 mm Ø at 0, 0.5, 1.0 and1.5%

43.25

C 2

41.67

41.17

48.90

0 %

0%

Mix designa tion

Lo ad (to ns)

7 da ys

C1

2.0 1

0.6 2

C2

1.9 6

0.6 1

Avg com p stg N/m m2

0.62

Lo ad (to ns)

28 da ys

6.4 5

2.0 1

6.3

1.9 6

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Avg split tensi le stg N/m m2

2.01

355

An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete (IJSRD/Vol. 2/Issue 07/2014/080)

3

2.0 8

C3

0.6 4

6.6

2.0 6

%

Table 10: Split Tensile Strength at 7 & 28 Days for CVC. Sl .

4% SilicaFume Steel Fiber

N o

Dia &leng th

Vf (%)

1

0% 0.5mm

2

ø &

0.5 %

3 30 mm 1%

4

1.5 %

Avg

Avg

Loa d

Loa d

Split tensil e

Split tensil e

(ton s) @7

(ton s)

stg

stg

7days

@28 days

N/m m2

days

28da ys N/m m2

C 1

2.5

09

0.72

1.04

C 2

2.8

10.5

0.87

1.25

C 3

2.65

12

0.82

1.46

C 1

3.21

11

1.0

1.31

C 2

3.15

13

0.98

1.59

C 3

3.2

15

0.99

1.87

C 1

3.3

C 2

3.25

16

1.01

2.0

C 3

3.4

18

1.1

2.28

C 1

3.60

13

1.21

1.59

C 2

3.42

15

1.12

1.87

C 3

3.35

17

1.15

2.09

14

1.04

@7

@28

Days

Days

N/m m2

N/m m2

1%

5

1.5 % 0.82

1.25

0.99

Loa d (ton s) @7

Dia &len gth

day s

Vf (% )

0.5m m

ø

0%

& 3

30 mm 0.5

S l.

1.73

Loa d

8% Silica Fume

(ton s)

1.05

2.0

1.16

N o

C 3

3.2

15

1.08

2.13

C 1

3.3

14

1.2

2.12

C 2

3.25

16

1.23

2.21

C 3

3.4

18

1.25

2.30

C 1

3.60

13

1.22

2.07

C 2

3.42

15

1.18

2.13

C 3

3.35

17

1.13

2.23

Lo ad

Steel Fiber

(to ns) @7

&len gth

1.85

@2 8 day s

Split tensi le

day s

Split tensi le

0 % 0.5m m 2

stg @7 7

28

days

days

N/m m2

N/m m2

ø

@28

&

days days N/m m2

2.5

09

0.89

1.13

C 2

2.8

10

0.98

1.28

C 3

2.65

12

0.92

1.50

3.21

11

1.09

2.0

Vf (% )

1

Avg

stg

C 1

C 1

2.07

1.07

2.06

1.23

2.21

1.25

2.24

Avg

N/m m2

3 2

1.03

1.59

Avg

N o

13

Dia

Sl .

Steel Fiber

3.15

Table 12: Split Tensile Strength at 7 & 28 Days of age of 8% silica fume with steel fibers of 0.5mmØ at 0,0.5,1, & 1.5%

Table 11:Split Tensile Strength at 7 & 28 Days of age of 4% silica fume with steel fibers of 0.5mmØ at 0,0.5,1, & 1.5%.

1

4

C 2

0.5 %

30 mm

1 % 0.93

1.31

4 1.5 %

Lo ad (to ns) @2 8 day s

Avg 12% SilicaFume

7da ys

28d ays

N/m m2

N/m m2

C 1

2.5

09

0.87

1.10

C 2

2.8

10.

5

0.93

1.28

C 3

2.6 5

12

0.95

1.48

C 1

3.2 1

11

1.02

1.87

C 2

3.1 5

13

0.99

2.04

C 3

3.2

15

1.05

2.10

C 1

3.3

14

1.19

2.09

C 2

3.2 5

16

1.21

2.17

C 3

3.4

18

1.22

2.28

C 1

3.6 0

13

1.18

2.04

C

3.4

15

1.12

2.11

Spli t tens ile stg

Spli t tens ile stg

@28

@7

days

days N/m m2

N/m m2

0.91

1.28

1.02

2.00

1.20

2.18

1.21

2.20

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356

An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete (IJSRD/Vol. 2/Issue 07/2014/080)

2

ø

3.3 5

&

2 C 3

17

1.08

2.17 3

Table 13 : Split Tensile Strength at 7 & 28 Days of age of 12% silica fume with steel fibers of 0.5mmØ at 0,0.5,1, & 1.5%.

Loa Avg SI Mix Flexur Stee Silic d Flexur designatio al stg N l a (tons al stg n N/mm2 O ) N/mm2 1 2

0%

0%

3

0.5%

P1

1.1

4.11

P2

0.9

3.33

P3

1.2

4.90

4.11

P2

1.8

5.21

P3

1.9

5.28

P1

2.0

5.30

P2

2.2

5.35

P3

2.4

5.39

P1

2.6

5.42

P2

2.8

5.48

P3

2.7

5.51

Steel Fiber

30 mm 4

Dia &length

LOAD Vf (%)

(TONS)

Table 16: Flexural Strength Test Results at 28 days age of 8% silica fume with steel fibers of 0.5mmØ at 0,0.5,1, & 1.5% Avg

P1 P2

1.3

Avg

Dia

28days

Flexural stg

&length

N/mm2

@28

1

1.4

4.72

4.71

ø

1.5

P1

1.6

4.87

P2

1.8

4.95

P3

1.9

5.0

P1

2.0

5.03

P2

2.2

5.07

P3

2.4

5.10

P1

2.6

5.15

P2

2.8

5.21

P3

2.7

5.14

3

3

4

30 mm

4

8% SilicaFume

Avg Flexural

Dia LOAD &length Vf (%)

28days

stg

N/mm2

@28

(TONS)

Days N/mm2

1

0.5mm 0%

2

P1

1.3

4.90

P2

1.4

4.97

P3

1.5

5.0

P1

1.6

5.15

4.82

P2

1.4

4.95

P3

1.5

4.98

P1

1.6

5.10

P2

1.8

5.17

P3

1.9

5.21

P1

2.0

5.25

P2

2.2

5.28

P3

2.4

5.32

P1

2.6

5.40

P2

2.8

5.44

P3

2.7

5.4

4.92

5.16

5.28

5.41

1.5%

Table 17: Flexural Strength Test Results at 28 days age of 12% silica fume with steel fibers of 0.5mmØ at 0,0.5,1, & 1.5%.

Table 15: Flexural Strength Test Results at 28 days age of 4% silica fume with steel fibers of 0.5mmØ at 0,0.5,1, & 1.5%.

Steel Fiber

1.3

5.17

1.5%

SINO

30 mm

5.06

1%

P1

1%

4.95

0.5%

&

28days N/mm2

0.5%

4.75

4.95

comprressive Strenght N/mm2

2

ø &

P3

LOAD

0% 2

0%

@28

(TONS)

Vf (%)

0.5mm

Days

4.65

Flexural stg

Days N/mm2

N/mm 0.5mm

12% SilicaFume

Steel Fiber

2

1

5.47

1.5%

SINO

4% SilicaFume

5.34

1%

Table 14: Flexural Strength Test Results at 28 days for M 30 grade mixes SINO

5.21

50 40 30 20

7days

10

28days

0 0

4 8 12 Silica Fume %

Graph 1: Compressive strength at 7and 28 days of age at 0%, 4%, 8 % and 12% of Silica Fume and without steel fiber

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357

Split Tensile stg at 28 days

compressive strenght at 7 days 50 40 30

silica 4%

20

silica 8%

10

silica 12%

0 0

2 1.5 4 silica 1

8 silica 12 silica

0.5 0

0.5 1 1.5 Steel fiber (Vf%)

0

50 45 silica 4% 40

silica 8% silica 12%

35

0.5 1 1.5 Steel fiber (Vf%)

Split Tensile stg at 7 days

compressive strenght at 28 days

0

Split tensile stgN/mm2

2.5

1.4 1.2 1 0.8 0.6 0.4 0.2 0

Split tensile stgN/mm2

compressive strenght (fc) Mpa

compressive strenght (fc) Mpa

An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete (IJSRD/Vol. 2/Issue 07/2014/080)

4 silica 8 silica 12 silica 0

0.5 1 1.5 Steel fiber (Vf%)

Graph 2: compressive strength at 7 and 28 days of age for 0%, 4%, 8 % and12% of Silica Fume with steel fiber of 0.5 mm Ă&#x2DC; at 0, 0.5, 1.0 and1.5%.

Graph 4:-Split tensile strength at 7 and 28 days of age for 0%, 4%, 8 % and12% of Silica Fume with steel fiber of 0.5 mm Ă&#x2DC; at 0, 0.5, 1.0 and1.5%

Flexural strenght in N/mm2

split tensile strenght in N/mm2

2.5 2

0.5 1 1.5 Steel fiber (Vf%)

28 days curing

5.4 5.2

1.5 1

7days 28 days

0.5

5 28 days curing

4.8 4.6

0 CVC (0)

4 8 Silica Fume %

12

Graph 3: Split tensile strength at 7 and 28 days of age at 0%, 4%, 8 % and 12% of Silica Fume and without steel fiber

4.4

Silica Fume %

Graph 5: Flexural strength at 28 days of age at 0%, 4%, 8 % and 12% of Silica Fume and without steel fiber

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An Experimental investigation on effect of Silica Fume and Steel Fibre on M30 Grade of Concrete (IJSRD/Vol. 2/Issue 07/2014/080)

[6] [7] [8] [9]

5.6 5.4 5.2 5

4% silica

4.8

8% silica

4.6

12% silica

IS 10262-1982 concrete mix Design.

IS 516-1959 Method of Test for Strenght of concrete.

IS 5816-1970 Splitting Tensile Strenght of concrete.

IS 456-2000 plain and Reinforced concrete code of practice.

[10] “concrete Technology” Theory and practice By MS SHETTY

4.4 4.2 0%

0.50%

1%

1.50%

Graph 6: Flexural strength at 28 days of age for 0%, 4%, 8 % and12% of Silica Fume with steel fiber of 0.5 mm Ø at 0, 0.5, 1.0 and1.5%.

V. CONCLUSION (1) The weight density of concrete increase with increase in the steel fiber content. .

(2) The compressive strength increases significantly due to addition of silica fume compared with normal concrete. The maximum increase in compressive strength was 15.63% at 28 days of curing for 8% of silica fume replaced by OPC cement.

(3) The compressive strength increases with the addition of steel fiber was marginal as compared with silica fume concrete.

(4) The split tensile strength increases with the addition of silica fume significantly compared with normal concrete. The maximum increase in split tensile strength was 6.52% at 28 days of curing for 8% of silica fume replaced by OPC cement.

(5) The split tensile strength increases with the addition of steel fiber was marginal as compared with silica fume concrete.

(6) The flexural strength increases with the addition of steel fibers with 8% silica fume then normal concrete. The maximum increase in flexural strength was upto 26.76% and 29.99% and 33.09% at 28 days of curing at 0.5%, 1% and 1.5% of steel fibers.

(7) The flexural strength increases with the addition of silica fume was marginal as compared with steel fiber concrete.

REFERENCES [1] Pawade Prashant.Y, Nagarnaik P.B and Pande A.M, “Influence of Silica fume in enhancement of compressive strength,flexural strength of steel fibers concrete and their relationship”, International Journal of Civil and Structural Engineering, Volume 2, No 1, 2011.

[2] H. Katkhuda, B. Hanayneh and N. Shatarat, “Influence of Silica Fume on High Strength Light weight Concrete”, World Academy of Science, Engineering and Technology, 58, 2009, pp 781to 788.

[3] IS 8112-1987 43 Grade OPC Specification.

[4] IS 8112-1989 43 Grade OPC Specification.

[5] IS 383-1970 Specification for CA & FA.

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