8/13/2019 FRC Presentation
1/37
http://www.animationfactory.com/free/buildings/structures_variant_page_church_glowing_sky.html8/13/2019 FRC Presentation
2/37
Fibre Reinforced Concrete
BY
ANAND
KIT
8/13/2019 FRC Presentation
3/37
Seminar Overview at a Glance
Introduction
What is FRC ?
Types of FRC Behavior of FRC
Properties of FRC
Applications of FRC Conclusion
8/13/2019 FRC Presentation
4/37
Concrete
Cement
Fine Aggregate
8/13/2019 FRC Presentation
5/37
Concrete
Advantages
Can be cast in diverse shapes
High compressive strength
High stiffness
Low thermal and electrical conductivity
Low combustibility and toxicity .
8/13/2019 FRC Presentation
6/37
Concrete
Limitations
Weak in Tension
It is Brittle in nature
How to overcome theselimitations ???
8/13/2019 FRC Presentation
7/37
NowFibre
Reinforced
ConcreteComes to Picture
8/13/2019 FRC Presentation
8/37
8/13/2019 FRC Presentation
9/37
Special Features of FRC
Thinner & Stronger Element
Reduce Weight of the structureControl cracking by adding small amount of fibres
Increases the Tensile strength
Increases Toughness
Increases Flexural strength
8/13/2019 FRC Presentation
10/37
For Effective use of fibres in hardened
concrete Fibres should be significantly stiffer than the matrix,ie a higher modulus of elasticity.
Fibre content byv o l u m e
must be adequate.
There must be a good fibre-matrix bond.
Fibre length must be sufficient.
Fibres must have a high aspect ratio
8/13/2019 FRC Presentation
11/37
Types of Fibres
Metallic
NaturalGlass
Polymeric
8/13/2019 FRC Presentation
12/37
Metallic Fibres
Made of either carbon steel or stainless steel
Tensile strength ranges from 345 to 1380 MPa
Minimum strength specified is 345 MPa
Modulus of Elasticity is about 200 GPa
Cross section of fibre may be circular, crescentshaped, square, or irregular
Length of fibre is normally less than 75 mm
Length to diameter ratio ranges from 30 to 100 ormore
8/13/2019 FRC Presentation
13/37
Metallic Fibres - Steel
Have rough surface hooked ends or are crimped orundulated through their length
Manufactured from drawn steel wire, from slit sheetsteel or by the melt-extraction process whichproduces fibres that have a crescent-shaped crosssection
Steel fibres have equivalent diameters (based oncross sectional area) of from 0.15 mm to 2 mm andlengths from 7 to 75 mm
8/13/2019 FRC Presentation
14/37
8/13/2019 FRC Presentation
15/37
Metallic Fibres - Steel
8/13/2019 FRC Presentation
16/37
DuctilityShear resistanceEnergy absorption
StiffnessSteel fibre as supplementary reinforcementin concrete could assist in the reduction ofspalling due to thermal shock and
thermal gradients.
Advantages of Steel Fibres
8/13/2019 FRC Presentation
17/37
Aspect ratio is defined as the ratio betweenfibre length and its equivalent diameter, which isthe diameter of a circle with an area equal to thecross-sectional area of the fibre.
Aspect ratios generally range from 20 to 100.
Stainless steel fibres have been used for high-temperature applications.
Aspect Ratio
8/13/2019 FRC Presentation
18/37
Polymeric Fibres
Polymeric or synthetic fibres are man-made fibresresulting from research and development in thepetrochemical and textile industries Two different physical fibre forms :
monofilament fibres fibres produced from fibrillated tape
Two synthetic fibre volumes used in application,namely :
low-volume percentage (0.1 to 0.3% byvolume)
high-volume percentage (0.4 to 0.8% by
volume).
8/13/2019 FRC Presentation
19/37
Polymeric Fibres
Acrylic
Aramid
Nylon
Polyester
Polyethylene
Polypropylene
Carbon
8/13/2019 FRC Presentation
20/37
Polymeric Fibres - Carbon
It is substantially more expensive than other fibretypes
Available in a variety of forms and have a fibrillar
structure similar to that of asbestos Available as continuous strands or as individual
chopped fibres
High tensile strength and modulus of elasticity and abrittle stress-strain characteristic
8/13/2019 FRC Presentation
21/37
Comparison of Concrete and Carbon-Fiber
Reinforced Concrete
Factor Conventional Concrete Carbon Fiber Reinforced Concrete
Weight Difficult to transport Easier to transport with 50% less
weight
Damage Quality control problems,corner damage andcracking during handling
Better quality control, tougher andhence easier to handle
Formability
Bar arrangement isdifficult, formation of ribs isdifficult
Casting and molding of complexarchitectural forms is possible,increased used in decorative outcrops
8/13/2019 FRC Presentation
22/37
Samples of various fibre reinforced plasticreinforcements (Picture courtesy ISIS Canada)
8/13/2019 FRC Presentation
23/37
Glass Fibre
Alkali-resistant glass fibre is used in the
manufacture of glass-reinforced cement (GRC)products, which have a wide range of applications.
Advantages of Glass Fibre
Lightweight Durable
Paintable
Impact Resistant Waterproof
Repairable
http://www.wtec.org/loyola/compce/fh02_02.gif8/13/2019 FRC Presentation
24/37
Use of FRC panels in theKita Kyusho Prince Hotel
http://www.wtec.org/loyola/compce/fh02_02.gif8/13/2019 FRC Presentation
25/37
Natural Fibres
Natural reinforcing materials can be obtained atlow cost and low levels of energy using localmanpower and technology
Two types of natural fibres : Unprocessed natural fibres Processed natural fibres
Unprocessed natural fibresCoconut coir, sisal fibres, sugarcane bagassefibres, bamboo fibres, jute fibres, flax andvegetable fibres
8/13/2019 FRC Presentation
26/37
Sisal-fibre reinforced concrete has been used formaking roof tiles, corrugated sheets, pipes, silos andtanks
Elephant-grass-reinforced mortar has been usedfor low-cost housing projects
Wood-cellulose-fibre-reinforced cement hascommercial applications in the manufacture of flatand corrugated sheet and non-pressure pipes
Applications of Natural Fibres
8/13/2019 FRC Presentation
27/37
Behavior of FRC
Stress - Strain behaviorUnder Tension
Under Compression
Torsion
Flexural
Toughness
Aspect ratio
8/13/2019 FRC Presentation
28/37
Stress - Strain behavior - Under Tension
Under high tensile load FRC will show more deformation thanplain concrete
8/13/2019 FRC Presentation
29/37
Stress - Strain behavior - Under Compression
As percentage of fibre increases, compressive stress increases
8/13/2019 FRC Presentation
30/37
Torsional
behavior of FRC
8/13/2019 FRC Presentation
31/37
Flexural behavior of FRC
Addition of fibres increases the moment carrying capacity of flexural
members
8/13/2019 FRC Presentation
32/37
Toughness
As the Volume of fibre is increased , toughness increases.
FRC is able to sustain load at deflection or strains much greater thanthose at which cracking first appears in the matrix
8/13/2019 FRC Presentation
33/37
Type of fibers used.Volume percent of fiber.
Aspect ratio (the length of a fiberdivided by its diameter).Orientation of the fibers in the matrix.
Properties influencing toughness andmaximum loading of FRC are
8/13/2019 FRC Presentation
34/37
Application of Various Fibres in Cement Products*
FibreType
Application
Glass Precast panels, curtain wall facings, sewer pipe, thin concrete shell roofs, wallplaster for concrete block.
Steel Cellular concrete roofing units, pavement overlays, bridge decks, refractories,
concrete pipe, airport runways, pressure vessels, blast-resistant structures, tunnellinings, ship-hull construction.
Popypr opylene,nylon
Foundation piles, prestressed piles, facing panels, flotation units for walkways andmoorings in marinas, road-patching material, heavyweight coatings for underwaterpipe.
Asbestos
Sheet, pipe, boards, fireproofing and insulating materials, sewer pipes, corrugatedand flat roofing sheets, wall lining.
Carbon Corrugated units for floor construction, single and double curvature membranestructures, boat hulls, scaffold boards.
MicaFlakes Partially replace asbestos in cement boards, concrete pipe, repair materials.
8/13/2019 FRC Presentation
35/37
Physical and Mechanical Properties of Selected Fibres.
FibreDiameter
mSpecificGravity
FailureSrain, %
Modulus ofElasticity, GPa
TensileStrength, GPa
Steel 5-500 7.8 3-4 200 1-3Glass 9-15 2.6 2-3.5 80 2-3
Polypropylene 7.5 0.9 20.0 5 0.5
Mica
Flakes 0.01-200 2.9 -- 170 0.25
Asbestos 0.02-20 2.5-3.4 2.3 200 3
Carbon 7.5 1.7-2.0 0.5-1.0 300-400 2-3
8/13/2019 FRC Presentation
36/37
Conclusion
Innovations in engineering design, which often establish the need
for new building materials, have made fibre-reinforced cements verypopular
The possibility of increased tensile strength and impactresistance offers potential reductions in the weight and thickness ofbuilding components and should also cut down on damage
resulting from shipping and handlingAlthough ASTM C440-74a describes the use of asbestos-cement
and related products, there are, at this time, no general ASTMstandards for fibre-reinforced cement, mortar and concrete.
Until these standards become available, it will be necessary to
rely on the experience and judgement of both the designer and thefibre manufacturer. The onus is thus on the designer to be aware ofthe limitations presently inherent in some of these composites,particularly the durability of glass-fibre-reinforced products.
8/13/2019 FRC Presentation
37/37
Top Related