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ACCENT JOURNAL OF ECONOMICS ECOLOGY & ENGINEERING Peer Reviewed and Refereed Journal, ISSN NO. 2456-1037

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“COMPARATIVE ANALYSIS OF CHARACTERISTIC COMPRESSIVE STRENGTH OF CONCRETE USING GLASS FIBRE AND STEEL FIBRE”

1Pradeep Kumar Jaiswal, ²Prof. C.S. Thakur

1Research Scholar, Department of Civil Engineering, SRGI, Jabalpur, M.P. India

2Professor, Department of Civil Engineering, SRGI, Jabalpur, M.P. India

Abstract - Experimental investigations are conducted to study the increase in compressive capacity of cubes made of Steel Fiber Reinforced Concrete (SFRC). In this research customized enlarged end fibers are used with a volume fraction of 0.4%, 0.8% and 1.2%.

Fibres are designed in different geometries to increase the bond and interfacial friction between aggregates and cement paste. Steel fibre texture such as crimped (zig-zag) shaped fibres improve the bond between the fibres within the matrix, thus increasing the necessary force required to pull out the fibre from the concrete. The tests were performed on 7, 14 and 28 days cured concrete. Compressive test shows the increase in strength when 0.8%

volume of sand replaced with steel fibre beyond this limit of fraction, decrement in strength has been recorded. This investigation proposes steel fibers as an additive for concrete to make good bondage which reduces the risk of brittle failure.

Keywords: Steel Fiber Reinforced Concrete (SFRC), Compressive Capacity, Steel Fiber Volume, Compressive Strength, Crimped Shape etc.

1 INTRODUCTION

Plain concrete is known to have low strength and low strain capacity, however these structural properties could be improved by addition of fibres. There are different fibres that are used in the concrete namely glass fibre, steel fibre, synthetic fibres and natural fibres(jute fibres). The improvement in the material behaviour of the fibre reinforced concrete depends on dosage and characteristics of the used fibres. Addition of randomly distributed steel improves concrete properties, such as static flexural strength, ductility and flexural toughness. The large number of fibres used for concrete members enables a uniform distribution of fibres through the compound, thereby creating a composite material possessing homogeneous mechanical behaviour. They provide a cohesive mix, creating a three dimensional reinforced net system. The important characteristic in FRC material is the bond between the fibers and the matrix. Fibres are designed in different geometries to increase the bond and interfacial friction between aggregates and cement paste.

Steel fibre texture such as zig-zag shaped fibres improve the bond between the fibres within the matrix, thus increasing the necessary force required to pull out the fibre from the concrete. The forces induced in a SFRC when subjected to load are redistributed within the concrete, which restrains the formation and

extension of cracks. The result is a more ductile reinforced concrete which is able to maintain a residual capacity in the post-cracking phase. Thus resulting in an increased load-carrying capacity, improved shear and bending strength of concrete, superior flexural ductility, toughness, and fatigue endurance.

A.M. Shende et. al.(2012), Critical investigation for M-40 grade of concrete having mix proportion 1:1.43:3.04 with water cement ratio 0.35 to study the compressive strength, flexural strength, Split tensile strength of steel fibre reinforced concrete (SFRC) containing fibers of 0%, 1%, 2% and 3% volume fraction. Steel fibers of 50, 60 and 67 aspect ratio were used. A result data obtained has been analyzed and compared with a control specimen (0%

fiber). Result data clearly shows percentage increase in 28 days Compressive strength, Flexural strength and Split Tensile strength for M-40 Grade of Concrete. Ahmad Bazgir (2016), a thesis on the behaviour of steel fibre reinforced concrete material and its effect on impact resistance of slabs, this study aims to investigate and examine the structural behaviour of steel fibre reinforced concrete material at different volume fraction of the fibers.

Experimental work is conducted for this research to obtain results on the behaviour of SFRC. The experimental

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ACCENT JOURNAL OF ECONOMICS ECOLOGY & ENGINEERING Peer Reviewed and Refereed Journal, ISSN NO. 2456-1037

Vol. 07, Issue 01,January 2022 IMPACT FACTOR: 7.98 (INTERNATIONAL JOURNAL) 47 work consists of testing concrete under

tension, compression and flexure.

Fiber Reinforced Concrete, research work the different types of fibres like steel, glass and synthetic fibres has been used in concrete and analyze the mechanical properties. This research also finds the flexural-tensile strength, resistance to spitting, impact resistance and excellent permeability and frost resistance of concrete using the fibres in certain limits. The research result also shows that it is an effective way to increase toughness, shock resistance and resistance to plastic shrinkage cracking of the mortar. Steel fibers can improve the structural strength to reduce in the heavy steel reinforcement requirement.

I.

2 METHODOLOGY

II.

2.1 Matrial Used

 Cement

Using Ordinary Portland Cement (grade 43) of specific gravity 3.14 conforming to IS 8112:2013, “ordinary Portland cement- specification”, has been used.

 Aggregates

Fine aggregates conforming to IS383:1970, “SPECIFICATIONS FOR COARSE AND FINE AGGREGATES FROM

NATURAL SOURCES FOR CONCRETE”

has been used.

Coarse aggregates conforming to IS383:1970, “SPECIFICATIONS FOR COARSE AND FINE AGGREGATES FROM NATURAL SOURCES FOR CONCRETE” has been used

Water

Normal portable water fit for drinking purpose has been used to prepare fresh concrete. Specification confirming to IS 456:2000.

 Concrete

The concrete is mixture of four main constituents: cement, water, coarse aggregate, and fine aggregate. The concrete was prepared of M20 for a characteristic compressive strength of 20MPa in 28 days from manufacturing.

 Steel Fibre

Steel fiber is a crimped metal reinforcement. Steel fiber for reinforcing concrete is defined as short, discrete

lengths of steel fibers with an aspect ratio (ratio of length to diameter) from about 20 to 100. They are generally of larger cross- section, with an „equivalent diameter‟ of 0.5-1.2 mm and lengths varying between 20 and 60 mm.

2.2 Experimental Setup A. Specimen layout

A total of 39 concrete specimens were prepared and tested in the experimental program having the size of 150mm×150mm×150mm. M20 grade of concrete has been as per the requirement for axial load design. Each cube specimen consists of a 150 mm square cross section and a depth of 150 mm. 9 plain concrete specimens (no replacement) were prepared and 27 steel fibre mixed concrete with different percentage of replacement were prepared. These specimens were prepared for 7, 14 and 28 days of curing respectively. The specimens were numbered as PC11, SC11, SC12 and so on, where the letter

“P” indicates Plain and “S” and “C” are indicating Steel Fibre and Concrete respectively. “C” indicates concrete which is the second word in abbreviation and the numeric value indicates the sequence in which they were tested in different group.

Figure 1: Steel Fibre

In this study, the steel were mixed homogeneously in the concrete mixture where they were integrated into the cube to form a full composite action. The first step in the strengthening process involved sizing, shaping, dressing, cleaning and removal of moisture (drying) from the steel fibre. During mixing we ensured the uniform distribution and shape of steel fibre. Accurate percentage weight has been taken during the preparation of specimens. These all parameters have been maintained in every specimen preparation.

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ACCENT JOURNAL OF ECONOMICS ECOLOGY & ENGINEERING Peer Reviewed and Refereed Journal, ISSN NO. 2456-1037

Vol. 07, Issue 01,January 2022 IMPACT FACTOR: 7.98 (INTERNATIONAL JOURNAL) 48 Figure 2: Shaping & sizing of Steel

Fibre B. Testing Programme

These specimens were subjected to axial compressive load using compressive testing machine of 2000KN capacity. The surface area of each specimen was 22500mm2. Ultimate load readings were taken to study the compression performance of the specimens. Prior to testing, all specimens were wiped off the water by a cloth and cleaned the surfaces of concrete and leave them at the room temperature for drying. After all these actions, putting the specimen by possessed a thick layer of paper fixed at the top and bottom surface of the specimen in order to ensure that the contact surface remained parallel and that the applied load remained concentric. The results of tested specimens were tabulated below, these results were recorded in ultimate loads at

which the failures of specimens occurred and further these loads are converted in ultimate stress that is ultimate load divided by cross sectional (surface area) area in which the load was applied.

Figure 4: (a), (b), (c) Arrangement &

Failure of Specime 3 RESULTS AND DISCUSSION

3.1 Stresses for Replaced & Without Replaced Concrete

The concrete specimens 0.4% and 0.8%

replacement of steel fibre recorded the stress as equal as plain concrete stress.

Beyond this limit concrete was not able to bear the same stress.

Table 1. Results obtained for concrete- specimen 7 Days Curing

Specimen

Name Percentage

Replacement No.of

Cube Pult(KN) σult (Pult/A) (MPa) Plain Concrete(PC)

(PC11+PC12+PC13)/3 0 3 534 23.7

Steel Fibre Concrete

(SC11) 0.4 3 530 23.56

(SC12) 0.8 3 535 23.85

(SC13) 1.2 3 550 24.59

14 Days Curing Specimen

Replacement No.of

Cube Pult(KN) σult(Pult/A) (MPa) Plain Concrete(PC)

(PC21+PC22+PC23)/3 0 3 657 29.2

(SC21) 0.4 3 655 29.04

(SC22) 0.8 3 545 25.63

(SC23) 1.2 3 630 28

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ACCENT JOURNAL OF ECONOMICS ECOLOGY & ENGINEERING Peer Reviewed and Refereed Journal, ISSN NO. 2456-1037

Vol. 07, Issue 01,January 2022 IMPACT FACTOR: 7.98 (INTERNATIONAL JOURNAL) 49 28 Days Curing

Specimen

Replacement No. of

Cube Pult(KN) σult (Pult/A) (MPa) Plain Concrete (PC) (PC 31+

PC32+PC33)/3

0 3 864 38.4

Steel Fibre Concrete (SC31)

0.4 3 797 35.41

(SC32) 0.8 3 610 27.26

(SC33) 1.2 3 613 27.26

(a)7 days,

(b)14 days

(c) 28 Days

Figure 5: % Replacement VS Ultimate Stresses for (a)7 days, (b)14 days & (c)

28 Days Cured Concrete 4 CONCLUSION

36 concrete specimens designated as

PC11, PC12, SC11, SC12 and so on were tested under axial compressive loading in compression testing machine of 2000KN capacity having the surface area 22500mm2. Comparative study has been carried out between plain concrete and steel fibre used concrete (PC & SC). This research work shows the following results

 Specimens mixed with steel fibres, the strength increases as we replace the steel fibre by 0.4% and 0.8%.

 Up to this limit concrete shows the good compressive as well as flexural strength.

 1.2% replacement of steel fibre starts reducing the strength.

 Mixing of steel fibre up to 0.8%, concrete shows the good cracking resistance.

REFERENCES

1. A.M. Shende et. al.(2012), Experimental Study on Steel Fiber Reinforced Concrete for M-40 Grade.

2. Ahmad Bazgir (2016), The behaviour of steel fibre reinforced concrete material and its effect on impact resistance of slabs.

3. A. Sivakumar, Manu Santhanam,

“Mechanical properties of high strength concrete reinforced with metallic and nonmetallic fibre”, cement and concrete composite 29 (2007) 603-608.

4. M. M. Islam et. al. (2014) Experimental Investigation of the Compressive, Tensile and the Flexural Capacity of Beams made of Steel Fiber Reinforced Concrete (SFRC).

5. Ganeshan N et al, (2007) „steel fibre reinforced high performance concrete for seismic resistant structure‟

6. Civil Engineering and construction Review, December 2007, pp 54-63.

7. Balaguru P and Najm H (2004), “High- performance fibre reinforced concrete mixture proportion with high fibre volume fractions”, Material Journal, volume 101, issue 4, July 1, 2004 pp281-286.