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Page 1

Seminar Report

On

STEEL FIBRE REINFORCED CONCRETE
(Submitted in partial fulfillment for the award of the degree of Bachelor of

Technology in Civil Engineering, Rajasthan Technical University Kota)

























Dr. P.K. AGARWAL SHOBHA MEENA
CRN - 11/361

Enrolment No.-
11EUCCE106



DEPARTMENT OF CIVIL ENGINEERING

UNIVERSITY COLLEGE OF ENGINEERING
RAJASTHAN TECHNICAL UNIVERSITY KOTA

MARCH 2015


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Department of Civil Engineering
University College of Engineering Rajasthan

Technical University, Kota-324010


Dated:



CERTIFICATE


This is to certify that Ms. Shobha meena College Roll No. 11/361 and

University Roll No. 11eucce106 has submitted the seminar report entitled “steel

fibre reinforced concrete’’ in partial fulfillment for the award of the degree of

Bachelor of Technology (Civil Engineering). The report has been prepared as per

the prescribed format and is approved for submission and presentation.





Counter signature of Head Signature of Guide





Dr. H.D. CHARAN Dr. P.K.AGARWAL
Professor& Head Associate professor
Dept. of Civil Engg. Dept. of Civil Engg
UCE, RTU, Kota-324010 UCE, RTU, Kota-324010


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From the shape of the stress strain curve it seems that, for a stress between 30 to 50% of Fu the

micro-cracks in the transition zone show some extension due to stress concentration to the tips

however, no cracking occurs in the mortar matrix. Until this point crack propagation is assumed

to be stable in the sense that crack lengths rapidly reach their final values it the applied stress

is held constant. For a stress between 50 to 75% of Fu increasingly the crack system tends to

be unstable as the transition zone crack begins When the available internal energy exceeds the

required crack release energy, the rate of crack propagation will increase and the system

becomes above 75% of Fu when complete fracture of the test specimen can occur by bridging

of mortar and transition zone cracks.

Based on the described cracking stages, the behavior of concrete can be viewed at two levels:

First, randomly distributed micro cracks are formed or enlarged under low level of stresses.

When tile stress level reaches a specific value, these micro-cracks begin to localize (strain

localization) and to coalesce into a macro-crack. This macro crack will agate until the stress

reaches its critical stage. Steady state propagation of this macro-crack will result in the strain

softening mechanism observed for concrete. This general view of cracking of concrete makes

it clear that the first linear elastic portion of loading up to strain localization cannot be described

by fracture mechanics but can be quantified using damage mechanics [Krajcinovic 1984].



FIGURE 4.2: Schematic Representation of Behavior of Concrete

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4.1.2. FOR STEEL FIBRE REINFORCED CONCRETE

Compressive strength is little influenced by steel fiber addition. High compressive this can be
achieved using silica fume or fly ash. However, the use of steel fibers the mode of failure of
high strength concrete from an explosive brittle one to a more ductile one, again showing the
increased toughness of SFRC and its ability to absorb energy under dynamic loading.

FIGURE 4.3: Compressive Strength of SFRC

The fiber type, volume fraction and aspect ratio play important roles in determining the

compressive ductility and energy absorption capacity of fiber reinforced concrete. The material

behavior is generally enhanced as the volume fraction and aspect ratio of fibers increase up to

limits after which the problems with fresh mix workability and fiber dispersibility start to

damage the hardened material properties. As the increases in both fiber volume fraction Vr and

aspect ratio 1/d lead to improvement of the same nature in the compressive behavior of the

material, their combined effect has been generally analyzed using the Fiber Reinforcing Index

Vr1/d. in general. The higher the fiber reinforcing index, the higher is ductility and energy

absorption capacity of fiber reinforced concrete. However, for high values of fiber reinforcing

index, the problems with workability and fiber dispersibility of fresh mix tend to deteriorate

the compressive behavior of the hardened material.

Due to their material properties, steel fibers do not at all influence the strength parameters of

concrete. Under compressive loading, when micro-cracking occurs because of transverse

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6.4 MAJOR STUCTURES OF SFRC ALL OVER THE WORLD







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REFERENCE

1. IS 456:2000

2. Concrete Technology: Theory and Practice by M.S.Shetty,

3. Perumalsamy N. Balaguru, Sarendra P. Shah, ‘‘Fiber Reinforced Cement Composites’’, Mc

Graw Hill International Editions 1992.

WEBSITES

www.wikipedia.com

www.civilengineering.com

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