FIBRE REINFORCED SELF COMPACTING CONCRETE- A REVIEW

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1 FIBRE REINFORCED SELF COMPACTING CONCRETE- A REVIEW Manjunatha J.K 1, Sanjith J 2, Ashwini B.T 3, Ranjith A 4 1 PG Student, 2, 3, 4 Assistant Professor Department of Civil Engineering, Adichunchanagiri Institute of Technology, (India) ABSTRACT In Concrete industry, it is widely accepted that the conventional concrete mixes are face down to plastic shrinkage during the phase of setting and this can often lead to cracking. Inclusion of relatively small amounts of fibre can adequately diminish this crunch by regulating this early age plastic shrinkage cracking. This paper discusses a comprehensive review on various aspects of Glass and Steel Fibre Reinforced Self Compacting Concrete concerning the behaviour, applications and performance. Keywords: Fibre Reinforced Self Compacting Concrete, Glass Fibres, Steel Fibres, And Mechanical Properties. 1. INTRODUCTION Fibre reinforced self-compacted concrete (FRSCC) is produced from cement, various sizes of aggregates, which incorporate with fibres. The term fibre reinforced concrete can be defined as concrete containing dispersed randomly oriented fibres. Inherently concrete is brittle under tensile loading and mechanical properties of concrete may be improved by randomly oriented discrete fibres which prevent or control origination, propagation or merging of cracks. The incorporation of fibres with adequate mechanical properties, into concrete matrix improves several properties such as toughness, increase resistance to fatigue, impact and blast loading, reduce spalling of the reinforcement cover and improve abrasion resistance and flexural and shear strength. The contribution of fibres to each mechanical and durability characteristics depend on many factors including fibre type, configuration, aspect ratio and volume fraction and other mixture parameters. Incorporation of glass fibres increases the strength of the concrete and decreases its unit weight Glass Fibres Glass fibre also called fiberglass. It is material made from extremely fine fibres of glass. Glass fibres are lightweight, extremely strong, and robust material but the strength is lesser than that of carbon fibre and it is less stiff, less brittle, and the raw materials are not muchexpensive. The bulk strength and weight properties of glass fibres are also very acclamatorycorrespond to metals. Glass fibres are favorable because of their extensive surface area to weight ratio. However, the extensive surface area leads to chemical attack. By ambushing air within them, blocks of glass fibre gives great insulation to heat. In contrast to carbon fibre, glass can go through more expansion before it clefts. Glass fibre has high tensile strength of about 1700 Mpa, four times higher than that of steel. The elastic modulus of these fibres is ten times higher than that of polypropylene fibres and finally 120 P a g e

There are various types of steel fibres such as wave cut, end large steel fibre, deformed sheet and also hooked end steel fibre.

2 these fibres are alkali resistant. For effective performance, the recommended dosage rate of glass fibres is 0.6 kg/m 3. Fig 1: Glass Fibres 1.2. Steel Fibres Steel fibre is the most common fibre type in the building industry. There are various types of steel fibres such as wave cut, end large steel fibre, deformed sheet and also hooked end steel fibre. Steel fibres acts as a bridge to retard their cracks propagation, and improve several characteristics and properties of the concrete. The addition of steel fibres does not change considerably the compressive strength and the modulus of elasticity of concrete but has noteworthy effects on the residual tensile strength and flexural strength. Fig 2: Steel Fibres 1.3 Need of Fibres in SCC Self compacting concrete develops micro cracks with curing and these cracks propagate rapidly under applied stress resulting in low tensile strength of concrete. Hence addition of fibres improves the strength of concrete and these problems can be overcome by use of glass fibres in concrete. Application of glass fibres provides strength to the concrete while the matrix protects the fibres. The primary role of fibres in a cementitious composite is to control cracks, increase the tensile strength, toughness and to improve the deformation characteristics of the composite. The performance of fibre reinforced self compacting concrete depends on the type of the fibres used. Inclusion of glass fibres reduces the water permeability, increases the flexural strength due to its high modulus of elasticity. In the post cracking stage, as the fibres are pulled out, energy is absorbed and cracking is reduced. II. LITERATURE REVIEW 2.1 Workability Abbas AL-Ameeri et al [1] observed the fresh properties of SCC with steel fibre, results indicated the reduction in workability with increase of steel fibre content. 121 P a g e

3 B. Krishna Rao et al [2] design a self-compacting concrete incorporating steel fibres and high volumes of class F fly ash. The HVFA SCCs have a slump flow in the range of mm, a T 50 slump flow ranging from 3.3 to 5 sec, a J-Ring test value ranging from 5 to 10mm, an L-Box ratio ranging from 0.8 to 0.94, and V-funnel flow in the ranging from 7.1 to 12sec. It was observed that it is possible to achieve self compaction with steel fibre inclusion. Although results obtained from all of the mixes satisfy the lower and upper limits suggested by EFNARC, all mixes had good flowability and possessed self-compaction characteristics. 2.2 Compressive Strength Compressive strength of concrete is one of the most important properties of concrete. It is a qualitative measure of concrete. Failure of concrete under compression is a mixture of crushing and shear failure. The compressive strength varies as a function of both cement paste and fibres. Higher binder ratio gives higher compressive strength. Ganeshan.N et al [3] found that the compressive strength improved on addition of 0.5 % of steel fibres in the concrete. From the Experimental investigation they found that the initial crack load and the post cracking performance were found to have enhanced due to the incorporation of steel fibres. B. Krishna Rao et al [2] observed a marginal improvement in the compressive strength. The incorporation of steel fibre increased the ductility significantly. The optimum volume fraction and aspect ratio of steel fibre for improved strength properties were found to be 1% and 25. Dr. Mrs. S.A. Bhalchandra et al [4] found that the hike in compressive strength with increase in volume fraction. The increase in compressive strength is 25.5% of Steel fibre reinforced SCC over normal SCC for the volume fraction of 1.75%. M. Mariappan et al [5] found that by adding 0.25% of steel fibres, compressive strength has increased nearly by 6%, by adding 0.50% of steel fibres, compressive strength has increased nearly by 12% and by adding 0.75% of steel fibres, compressive strength has increased nearly by 20%. Shahana Sheril P.T et al [6] observed the specimen with 0.05%, 0.1%, 0.15% and 0.2% of glass fibre shows an increase of compressive strength by 8.2%, 9.2%, 7.02% and 3.5% respectively than the SCC without fibre for the M20 grade mixes and the specimen with 0.05%, 0.1%, 0.15% and 0.2% of glass fibre has in increase compressive strength of 5.1%, 7.1%, 5% and 2.3% respectively than the SCC without fibre for M30 grade mixes. 2.3 Split Tensile Strength Dr. Mrs. S.A. Bhalchandra et al [4] observed from the experimental investigation that by the addition of fibres the split tensile strength of the SCC increases. The optimum volume fraction of fibres for increase in split tensile strength is 1.7% and percentage increase is 25% of Steel fibre reinforced SCC over conventional SCC. M. Mariappan et al [5] found that by adding 0.25% of steel fibres, Split tensile strength has increased nearly by 54%, by adding 0.50% of steel fibres, Split tensile strength has increased nearly by 88% and by adding 0.75% of steel fibres, Split tensile strength has increased nearly by double the amount as compared to ordinary self compacting concrete. M. Pajak et al [7]investigated the flexural performance of straight and hooked end steel fibre reinforced selfcompacting concrete. The type of steel fibres influences the post-peak performance of SCC. Also the addition of straight steel fibres influence the deflection-softening antiphon. Thus, at ultimate load the deflection of specimens reinforced with straight steel fibres was close to the deflection of conventional specimens. In case of 122 P a g e

4 the specimens reinforced with hooked end steel fibres the deflection at the ultimate load was much higher.generally, Self compacting concrete indicates similar flexural behavior to Conventional concrete. 2.4 Flexural Strength P. Srinivasa Rao et al [8] observed that by the addition of glass fibre in the self compacting concrete mix reduces bleeding, thus reduces the probability of cracks, improves the surface integrity of concrete and improves its homogeneity. The load carrying capacity of glass fibre reinforced self compacting concrete beams at 0.03 % are on higher side. The presence of glass fibres in glass fibre reinforced self compacting concrete beams have not improved any flexural strength. Vinayak B. Jatale et al [9] observed that by the incorporation of steel fibres in SCC extremely increases the flexural strength compared with conventional concrete. The maximum value of flexural strength gives the WSF at 3.5 % fibres content. Abbas AL-Ameeri et al [1] found an optimum content of steel fibre at which higher performance obtained, the content was 0.75%- 1%. As the volume fraction of fibres increased the strengths increased correspondently. The increase in fibres slightly decreases the U.P.V. III. CONCLUSION a) Glass fibre reduces the probability of cracks, improve the surface integrity of concrete and improve its homogeneity due to reduction in bleeding. b) Workability of self compacting concrete decreases with increase in steel fibre volume fraction. However, higher workability can be achieved with the addition of high range water reducers. c) Glass fibres enhance the strength of concrete, without causing the well-known problems, normally associated with steel fibres. d) Tremendous increase in compressive strength is reported with addition of steel and glass fibres. e) The durability of concrete improves and addition of steel and glass fibres greatly improves the fracture parameters of concrete. REFERENCES [1] Ganesan.N, Indira.P.V & Santhosh Kumar.P.T, Strength and Behaviour of Steel Fibre Reinforced Self Compacting Concrete in Flexure, International conference on Advances in Concrete, Composites and Structures, held at SERC, Chennai, 6-8 January,2005 PP [2] P Srinivasa Rao, G K Vishwanadh, P Sravana and T Seshadri Sekhar, Flexural Behaviour Of Reinforced Concrete Beams Using Self Compacting Concrete, 34th Conference on OUR WORLD IN CONCRETE & STRUCTURES: August 2009, Singapore. [3] B. Krishna Rao and V. Ravindra, Steel Fibre Reinforced Self compacting Concrete Incorporating Class F Fly Ash, International Journal Of Engineering Science And Technology,Vol. 2(9), 2010, [4] Abbas AL-Ameeri, The Effect of Steel Fibre on Some Mechanical Properties of Self Compacting Concrete, American Journal of Civil Engineering, Vol. 1, No. 3, 2013, pp doi: /j.ajce [5] Shahana Sheril P.T., Self Compacting Concrete Using Fly Ash and Glass Fibre,International Journal of Engineering Research & Technology (IJERT), ISSN: , Vol. 2 Issue 9, September P a g e

5 [6] M. Paja k and T. Ponikiewski, Flexural behavior of self-compacting concrete reinforced with different types of steel fibres, Construction and Building Materials 47 (2013) [7] Vinayak B. Jatale and M. N. Mangulkar, Flexural Behavior of Self Compacting High Strength Fibre Reinforced Concrete (SCHSFRC),International Journal of Engineering Research and Applications (IJERA) ISSN: , Vol. 3, Issue 4, Jul-Aug 2013, pp [8] Dr. Mrs. S.A. Bhalchandra and Pawase Amit Bajirao, Performance of Steel Fibre Reinforced Self Compacting Concrete, International Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 4. [9] M. Mariappan and R. Rajesh Guna, Structural Performance of Self Compacting Fibre Reinforced Concrete, International Journal of Science and Research (IJSR). 124 P a g e

Performance of Glass Fibre Reinforced Self Compacting Concrete

2015 IJEDR Volume 3, Issue 2 ISSN: 2321-9939 Performance of Glass Fibre Reinforced Self Compacting Concrete 1 Manjunatha J.K, 2 Ashwini B.T 1 PG Student, 2 Assistant Professor 1,2 Department of Civil Engineering,