Improvement Of Properties Of Concrete By Adding Fibers

( An Experimental Studying)

PROJECT TITLEPROJECT TITLE

Concrete is one of the most versatile building material. Concrete is strong under compression yet weak under

tension, brittle and limited ductility material.Therefore, a form of reinforcement is needed, steel

bars reinforce concrete against tension only locally. Cracks in reinforced concrete members extend freely

until encountering a rebar. The need for Multidirectional and closely spaced

reinforcement for concrete arises. FRC is a concrete mix that contains short discrete fibers

that are uniformly distributed and randomly oriented.

INTRODUCTION

Steel FibrePolypropylene FibreCarbon FibreGlass Fibre

Steel fibers are the most common fibers used in concrete .They may be produced either by cutting wires, shearing sheets or from a hot melt extract.

Steel fibers have high modulus of elasticity which is 10 times that of concrete, reasonably good bond and high elongation at fracture. Steel fibers range in length from 0.25 inches to 3.0 inches.

The raw material polypropylene, derived from the monomeric C3H6, is a pure hydrocarbon similar to paraffin wax. Its mode of polymerization, its high molecular weight, and the way it is processed into fibers combine to give polypropylene fibers

The concept of using fibers in concrete to improve resistance to cracking and fragmentation is old and intuitive.

During the last 30 years different types of fibers and FIBRE materials were introduced and are being continuously introduced in the market as new applications. These fibers can be made of metals, natural, glass or organic materials.

The philosophical objective of the thesis is to contribute to the knowledge of the properties of FIBRE reinforced concrete (FRC), helping to extend the use of the material to structural design.

Study of the effect of using polypropylene FIBRE and Steel FIBRE on concrete compressive and split tensile strength.

Concrete weak in tensile , brittle and limited ductility material.

Steel bars however, reinforce concrete against tension only locally.

Fiber reinforced concrete is used when there is requirement for eliminating small cracks.

LIMITATION OF THESIS

This thesis focuses on lab specimens testing only Polypropylene fibers and steel fibers are studied

PROBLEMS OF THESIS

Reviewing literatures : (Boxes, Magazines, Websites, Researches, and References).

Case study : By using combination of polypropylene and steel FIBRE and make study about it.

Data Collection : By experimental investigation where, one concrete mix made from local ingredients will be

used to cast and testing (7-day and 28-day curing) of 18

specimens.Result Discussion Of Experimental InvestigationAnalysis and Discussion Of ResultsConclusion

Flow Chart Of The Experiment

Total = 18 specimens

Fibre fraction by volume of concrete

MATERIALS USED IN AN EXPERIMENTAL

Specimens Casting Preparation of materials

Cement

The cement used in preparing the specimens was Ordinary Portland Cement (OPC) 53 grade Ultra Tech cement.

The coarse aggregate used in this investigation is from Morbi city.

Specific gravity of aggregate was found to be 2.65.

Coarse Agagregate (20mm and10mm)

IS sieve size Cumulative % of weight retained

Cumulative % passing

80 mm 10040 mm 10020 mm 18.4 81.610 mm 98.64 1.364.75 mm 99.84 0.162.36 mm 99.92 0.081.18 mm 100 0600 micron 100 0300 micron 100 0160 micron 100 0PANTOTAL 616.88

%

The fine aggregate used in this investigation was sand from Morbi city.

The specific gravity of 2.50 according to Pycnometer Test.

Fine Aggregate

IS sieve size Cumulative % of weight retained

Cumulative % passing

10 mm 0 1004.75 mm 0 1002.36 mm 5.2 94.81.18 mm 29.2 70.8

600 micron 30.4 69.6300 micron 83.6 16.4150 micron 98.4 1.690 micron 99.2 0.875 micron 99.6 0.4

PAN 100 0.0TOTAL %545.6  

Commercially available polypropylene fibers is 12 mm length fibrillated chopped was used as shown in picture below.

Specific Gravity of fibre was found to be 0.9

Polypropylene Fibers

Commercially available Toothed End Steel Fibers of 30mm length was used

Specific Gravity of fibre was 7.8.

Steel Fibers

Mix Type Cement

Sand Course aggrega

tes

Steel fibers

Polypylene fibers

%0 1 1.206 2.790 - -

0.5% fiber25%SF+75%PP

F

1 1.206 2.790 0.0318 0.0113

0.5% fiber 50%SF+50%PPF

1 1.206 2.790 0.0636 0.0073

Mix Proportions By Weight, With PPF and SF By Weight* of Cement Content (W/C=0.44)

Fibre Content

Fibre Ratio 7 Days 28 days

0% N.A. 20.34 31.980.5%(By volume)

25%SF +75%PPF

22.23 34.22

0.5%(By volume)

50%SF +50%PPF

23.48 35.09

SF- steel fibrePPF – polypropylene fibre

Compressive strength behavior of FRC mixes with varying % Steel and polypropylene fibre * 0.5% fiber content by volume

Fiber Percentage

Fraction)%(

Compressive

Strength7-day

(MPa)

Compressive

Strength28-day

(MPa)

Percentage)%(  

28-day

7-day%0 20.34 31.98 100 10025%SF+75%PPF

22.23 34.22 109.29 107.04

50%SF+50%PPF

23.48 35.09 115.33 109.72

* Average of 3 Specimens. Effect of Polypropylene Fibers and steel fibers on the Strength of the

Concrete

Slabs - fibers increase dynamic loading resistanceI. Industrial floor slabsII.Slabs on grade III.Warehouses floor slabsIV.Garage floorsV.Drive waysVI.Bus stop padsVII.Airport Slabs

Building systemsI. Slabs, footingII. Shear wallsIII. Curtain wallsIV. Precast elements Tunnel BuildingI. Shotcreted line tunnelsII. Railway tunnels

Applications Of Fiber Reinforced Concrete

1) Hannant, D. J., “Fiber Cements and Fiber Concretes”, John Wiley & Sons Ltd., 1978.

2) Fiber Reinforced Concrete (Portland cement association),1990.

3) "Fiber Reinforced Concrete Developments And Innovation" James I. Daniel and Surendra P. Shah, American Concrete Institute Detroit, Michigan,1994 .

4) www.concrete fiber.com

Will be working on improving Tensile strength by using different proportions.

Will be working on Flexural strength by using different proportions.

Guided by : Prof. K.B. Vaghela

Prepared by : Shailesh Kataria Divyesh Kalsariya Ravi Kant Pandey Shailesh Kalsariya