INTRODUCING GILL CELLS IN PONTOON-TYPE FLOATING STRUCTURES

FIBER REINFORCED CONCRETE IN INDUSTRIAL FLOORSGuided By: ANU MATHEW Asst ProfCivil Engg Dept

Presented By: AMAL THANKACHANS7, Roll no: 7Civil Engg Dept

MAIN JOURNELApplications and Prospects of Fiber Reinforced Concrete in Industrial Floors , (21 May 2015) , Hesham Alsharie (Civil Engineering Department, Faculty of Engineering, Jerash University, Jerash, Jordan) mlmce civil dept.2

CONTENTS Introduction Industrial floor characters FRC FRC in Industrial floorComparison of FRC and conventional concreteCase Study Conclusion References

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INTRODUCTIONFloors are given to provide a surface for the production and peoples activities.

Industrial floors must have strength and endurance to resist tensile, compressive and bending forces, also impacts and abrasion.

Also it should be resistant to aggressive physical and chemical factors

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To obtain good properties of the floor we can add fiber to the concrete.

The fiber reinforced concrete will provide a good resistance against , compressive and bending forces, impacts and abrasion

By using FRC in floors we can reduce the thickness of industrial floors

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INDUSTRIAL FLOORS CHARACTERSIndustrial floor is an important structure due to its relation to quality of production, labor comfort, and human health.Flooring costs reach 20% of singlestory building and it consumes 40% - 50% of total concrete.Flooring is consist of four parts1) Flooring 2) Subfloor (underlayment)3) Damp proofing 4) Grademlmce civil dept.6

Industrial floors should resist very harsh mechanical impacts

The industrial floor should have property of dust separation and conductivity; they must be non-sparking; with special thermal engineering requirements.

Also floors should be resistant to high temperature or various chemical environments, including aggressive environment

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Types of floorThe floors are classified in to five types Class I - Ordinary floors

Class II - Floors having property to carry extra load

Class III Floors with special requirements Class IV- Floor which automated lines are fixed

Class V-floor providing damp proofing

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Strength of Floors Subfloor is the main part of industrial floors it distribute the loads to the grades Hard subfloor must be made of concrete C20/25 at least if we dont want hard subfloor we can use lower classes, but not less than c8/10The thickness of floor should not be less than 100mm When using concrete subfloor as flooring, its estimated thickness must be increased by 20 - 30 mm. By using FRC we can reduce the thickness and also can increase the properties of industrial floors

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FIBER REINFORCED CONCRETE(FRC)

Fiber Reinforced Concrete is a composite material consisting of cement, aggregate and discontinues, discrete, uniformly dispersed suitable fibers.

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WHY USE FIBER IN INDUSTRIAL FLOORS?Plain concrete is a brittle material with limited ductility and low tensile strength and strain capacity. If the concrete have any internal micro-cracks are present in concrete. Thus the concrete leads to heavy brittle fracture. The role of randomly distributed fibers is to bridge across the cracks and to provide some post-cracking ductility. If the fibers are sufficiently strong and bonded to material then FRC will carry significant stress over a relatively large strain capacity in the post cracking stage. mlmce civil dept.11

DIFFERENT TYPES OF FIBERmlmce civil dept.12

STEEL FIBERNATURAL FIBERGLASS FIBERSYNTHETIC FIBER

PROPERTEIS OF DIFFERENT FIBERSType of fiberTensile strength(Mpa)Youngs modulus(x103Mpa)Ultimate elongation(%)Steel 275-27572000.5-35Polypropylene551-6903.45~15Glass1034-3792~691.5-3.5Nylon 758-8274.1416-20

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PRACTICAL APPLICATION OF FIBER TO THE CONCRETEThere are mainly three methods to apply fiber in to concrete 1)Add the fibers to the truck mixer after all other ingredients , including the water, have been added and mixed.2)Add the fibers to the aggregate stream in the batch plant before the aggregate is added to the mixer.3)Add the fibers on top of the aggregates after they are weighed in the batcher.mlmce civil dept.14

PROPERTIES OF CONCRETE IMPROVED BY FIBERS MECHANICAL PROPERTIESCompressive strength-Presence of the fiber in concrete will only have minor effect on the improvement of compressive strength values (0 to 15 percent)

The modulus of elasticity of FRC increase slightly with an increase in the fibers content. It was found that for each 1% increase in fiber content by volume there is an increase of 3% in the modulus of elasticity

The flexural strength will be increased by 2.5 times using 4 percent fibers.

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For FRC, toughness is about 10 to 40 times that of plain concrete.

The presence of 3 percent fiber by volume was reported to increase the splitting tensile strength of mortar about 2.5 times that of the unreinforced one.

The impact strength for fibrous concrete is generally 5 to 10 times that of plain concrete depending on the volume of fiber used.

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Tensile strength-In direct tension, the improvement in strength is reported from 30-40% for addition up to 2% by total volume of fibers . It is observed that the split tensile strength increases from 10-45% for addition up to 3% by total volume of fiber

In FRC there is a significant increase in flexural fatigue strength with increasing percentage of steel fibers. Almost 1 1/2 times increase in fatigue strength due to the increasing use of steel fibers.

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STRUCTURAL BEHAVIOR OF FRCThe use of fibers in reinforced concrete flexure members increases ductility, tensile strength, moment capacity, and stiffness. The fibers improve crack control.

The use of fibers eliminate the sudden failure characteristic of plain concrete beams. Addition of randomly distributed fibers increases shear-friction strength, the first crack strength, and ultimate strength. In conventionally reinforced concrete beams, fiber addition increases stiffness, and reduces deflection.

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Factors affecting the Properties of FRC Volume of fibers

Aspect ratio of fiber

Orientation of fiber

Relative fiber matrix stiffness

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LIMITATIONS OF STEEL FIBER REINFORCED CONCETEReduces the workability. Loss of workability is proportional to volume concentration of fibers in concrete. Higher aspect ratio also reduced workability.

Another problem is the corrosion of the surface which may influence the appearance of the surface.

Unless steel fibers are added in adequate quantity, the desired improvements cannot be obtained.

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FRC IN INDUSTRIAL FLOORSIn industrial floors we mainly use steel fiber it increase the tensile strength of concrete.

If there is no steel fiber, micro-cracks, as they accumulate, turn into macro-cracks and lead to the destruction of concrete or loss of such properties as water and frost resistance, resistance to aggressive impacts, etc.

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When we use fiber will act as in fig A&B

By providing steel fiber in industrial floors we can increase crack , impact , wears and frost resistance.

By adding fiber into concrete we can reduce shrinkage and creep

By adding the fiber we have more possibility to use more efficient design solutions without rod and transverse reinforcement, etc.

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By adding fiber in concrete we can reduce labours it reduces labour cost , increased degree of mechanization , and automation of the production of reinforced concrete structures.

Fiber reinforcement reduces the thickness of the subfloor about 20% - 30%, hence enabling to reduce the consumption of cement and fillers. The use of fiber meshes will enable to save 30% - 40% of steel.

By providing fiber reinforcement we can reduce the time consuming by eliminating reinforcement works mlmce civil dept.24

COMPARISON OF FRC AND STANDARD CONCRETE The standard concrete will have less thermal resistivity and when exposes to temperature it will distress but in FRC the structure have more stability in high temperature

The FRC is 500 times more resistant to cracking and 40 percent lighter than traditional concrete

The FRC has more tensile strength than standard concrete

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Structural behavior at Elevated Temperature mlmce civil dept.26

mlmce civil dept.27Fiber Reinforced ConcreteNormal Reinforced concreteHigh DurabilityLower DurabilityProtect steel from CorrosionSteel potential to corrosionLighter materialsHeavier material More expensiveEconomicalWith the same volume, the strength is greaterWith the same volume, the strength is lessLess workability High workability as compared to FRC.

Comparison of FRC and plain concreteThe FRC has more ductility than plain concrete also it have more compressive and tensile strength .Plane concrete is brittle. The 14-days strength of FRC was about 20% higher than that of plain concrete.

mlmce civil dept.28Material Plain concreteFiber reinforced concreteCement446519Water (W/C=0.45)201234Fine aggregate854761Coarse aggregate682608Fibers (2% by volume) --157

STRESS STRAIN RELATIONSHIP OF PLAIN CONCRETE AND FRCmlmce civil dept.29

THE CRACKING CONDITION OF BOTH FRC AND PLAIN CONCRETE

CASE STUDYIn the New Zealand concrete industry, the SFRC is introduced as Steelcrete and introduced by Firth in 1996

In 1998 Firth constructed a industrial floor of Casborns Cool Store of Hastings of dimensions of 51x135m and thick of 125mm was founded on a sub-grade having a CBR of 15%

The total SFRC volume poured in the floor was 865m with a concrete specified strength of 30MPa containing a dosage of 20kg/m of Dramix RC65/60BN fibres.

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A single sheet polythene was layed underneath the floor to reduce the plastic and drying shrinkage stresses. The floor was designed to carry a UDL of 5kPa, 8-tonne standard 4-wheel truck axle load and 5-tonne, 2-wheel hoist axle load.

By providing SFRC to floor it saves 17% concrete by reducing the thickness into 125mm.

In service, the Steelcrete floor has performed very well by providing a remarkable resistance to impact, corrosion and spalling of concrete edges along joint lines under heavy axles. mlmce civil dept.31

CONCLUSIONThe use FRC in industrial flooring is because of its effect on labor comfort, process quality, and money savings.

And it have better resistance on creep and impact load it also reduces the maintenance cost also it reduce 10%-30% in case of cost

The use of FRC instead of concrete reduces the thickness of slab and it increases the resistant to tensile loads, chemical environmental etc.

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REFERENCEFiber reinforced cement-based (FRC) composites after over 40 years of development in building and civil engineering (March 2008), Andrzej M. Brandt (Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland)

State-of-the-Art Report on Fiber Reinforced Concrete ,(reapproved 2002),Reported by ACI Committee 544

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Properties and Applications of Fiber Reinforced Concrete(JKAU: Eng. Sci., Vol. 2, pp. 49-6~ (1410 A.H./19lJlI A.D.))FAISAL FOUAD WAFA(Associate Professor, Civil Engineering Department , Faculty of Engineering, King Abdulaziz University , Jeddah, Saudi Arabia.) Comparison of Performance of Standard Concrete And Fiber Reinforced Standard Concrete Exposed To Elevated Temperatures (Volume-02, Issue-03, pp-20-26 ,2013),K . Srinivasa Rao , S . Rakesh kumar , A . Laxmi Narayana (Associate Professor, Department of Civil Engineering, Andhra University, Visakhapatnam. Former PG Students (M.E Structures), Andhra University, Visakhapatnam). mlmce civil dept.34

An experimental study of synthetic fiber reinforced cementitious composites(journal of material science 22 ,1987), YOUJIANG WANG* , STANLEY BACKER **, VICTOR C. L^(*Department of Mechanical Engineering and ,**Department of Civil Engineering , Massachusetts Institute of Technology , Cambridge Massachusetts 02139, USA) Floors and pavements (march 2005) , by Firth steelcrete mlmce civil dept.35

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