DEAR FRIENDS ,,,, THIS POWERPOINT PRESENTATION MAY INCLUDE ON CE 6002 CONCRETE TECHNOLOGY UNIT 5 FOR FIFTH SEMESTER CIVIL ENGINEERING STUDENTS (2013_ REGULATION) G.GUNA AP / CIVIL SRVEC

1. DEPARTMENT OF CIVIL ENGINEERING
CE 6002 – CONCRETE TECHNOLOGY
1G.GUNA SRVEC

2. OUTLINE
This presentation may include on
1) Light weight concrete
2) Highstrengthconcrete
3) Ferro cement
4) Ready mix concrete
5) Fiber reinforcedconcrete
6) Geo polymer concrete
7) SHOTCRETE TECH.
8) SIFCON
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3. LIGHT WEIGHT CONCRETE
concrete which uses lightweight aggregates
May consist of lightweight aggregates are
used in ordinary concrete of coarse
aggregate and sand, clay, foamed slag,
clinker, crushed stone, aggregates of organic
and inorganic.
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4. Methods of preparation of lightweight concrete
3.Providing lightweight
aggregate concrete
1.Preparation of
porous concrete
2.Without
providing concrete
smoother (rough
concrete)
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5. 1.PREPARATION OF POROUS CONCRETE
a) Lightweight concrete obtained by inserting
gas bubbles or air into the mixture of plastic
cement (mixed with fine sand)
b) Lightweight concrete did not contain stones
included as porous mortar.
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6. Characteristics of porous concrete
2. a high
moisture
movemen
t
3. a high
shrinkage
1. high
thermal
insulation
POROUS CONCRETE 6G.GUNA SRVEC

7. Types of porous concrete
Aggregates used shall comply with the
following conditions:
a) At least 95% of aggregates must be via the 18mm BS sieve.
b) The stone aggregate used shall not exceed 10% by 10 mm BS
sieve.
c) Stone did not diffuse through the BS 4mm sieve. 7G.GUNA SRVEC

8. Preparation of concrete without the smooth
(rough concrete)
 Lightweight concrete such as is obtained when the fine
aggregate (sand) is not used and the concrete mix of cement, water
and coarse aggregates.
Concrete can be used for structural purposes and not to bear
burden to bear a load.
Preparation of lightweight aggregate concrete
)
.
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9. The main purpose of the concrete requirements are:
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10. Characteristics of Lightweight Concrete
1. Thermal insulation
2. Fire insulation
3. Durability
4. Rain penetration
5. Acoustic properties
6. Water absorption
Thermal insulation
Thermal insulation efficiency is defined as resistance to heat
flow either through conduction, or radiation.
Lightweight concrete has a high heat insulation resistance.
such as porous concrete walls 150mm to provide four times
better insulation than 225mm thick brick wall.
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11. Fire insulation
Durability
It is defined as the ability to bear the effects of environment such
as the effects of chemical, physical stress and mechanical effects.
The intended effect of the chemical, including ground water
containing sulfate, air pollution and reactive liquid spills.
Physical stress is the shrinkage, the stresses of temperature,
cooled, and others. If all the physical stress will cause cracks in the
structure of lightweight concrete.
Mechanical effect is the impact and costs are excessive. The
situation in the steel structure unit should be protected from rusting.
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12. Water absorption
Absorption water by the concrete is high and more than that found in
solid concrete. This is because the lightweight concrete has holes in it.
Penetration of rain water
It is an important element to the wall
Acoustic properties
The key factor is the density of the sound insulation material. Therefore,
for sound insulation, lightweight concrete can not show the desired
characteristics.
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13. i) rapid and relatively simple construction
ii) Economical in terms of transportation as well as reduction in
manpower
iii) Significant reduction of overall weight results in saving structural
frames, footing or piles
iv) Most of lightweight concrete have better nailing and sawing
properties than heavier and stronger conventional concrete
i) Very sensitive with water content in the mixtures
ii) Difficult to place and finish because of the porosity and
angularity of the aggregate. In some mixes the cement mortar may
separate the aggregate and float towards the surface
iii) Mixing time is longer than conventional concrete to assure
proper mixing
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14. New Innovative Lightweight FoamConcrete Technology
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15. HIGH STRENGTH CONCRETE
HISTORY OF CONCRETE:
 The word concrete comes from the Latin word "concretus"
Which means compact or condensed.
 German archaeologist Heinrich Schliemann found concrete
floors, which were made of lime and pebbles, in the royal
palace of Tiryns, Greece, which dates roughly to 1400-1200
BC.
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16. INTRODUCTION TO CONCRETE:
 A building material made from a mixture of broken stone or
gravel, sand, cement, and water,which can be poured into
moulds and forms a stone-like mass on hardening.
 It is strong in compression and very weak in tension.
TYPES OF CONCRETE:
1) Normal concrete 5) Self Compacting Concrete
2) High Strength Concrete 6) Shotcrete
3) Air Entrained Concrete 7) High Performance Concrete
4) Light Weight Concrete
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17. HIGH STRENGTH CONCRETE:
 High-strength concrete has a compressive strength greater than 40 MPa.
 High strength concrete is made by lowering the water cement (W/C) ratio
to 0.35 or lower.
 Due to low w/c ratio it causes problem of placing ,to overcome from this
super plasticizer used.
Materials for High-StrengthConcrete:
Cement:
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18. Aggregate:
Methods Of Making HSC:
 Use Of Admixture
 Use Of Cementitious Agg
 Seeding
 High Speed Slurry Mixing
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19. Guidelines for the selection of materials:
 The higher the targeted compressive strength, the smaller the
maximum size of coarse aggregate.
 Up to 70 Mpa compressive strength can be produced with a
good coarse aggregate of a maximum size ranging from 20 to
28 mm. •
 To produce 100 Mpa compressive strength aggregate with a
maximum size of 10 to 20 mm should be used.
APPLICATION OF HSC:
 Use of HSC in column section decreases the column size.
 Use of HSC in column decreases amount of steel required for
same column.
 In high rise building, use of HSC increases the floor area for
rental purpose.
 In bridges , use of HSC reduces the number of beams
supporting the slab.
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20. WHAT IS FERRO CEMENT ?
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21. TECHNIQUES OF MANUFACTURES
 Hand plastering
 semi-mechanised process
 Centrifuging and Guniting
MATERIALS USED IN FERRO CEMENT
 Cement mortar mix
 Skeleton steel
 Steel mesh reinforcement or Fibre-reinforced polymeric
meshes
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22. CEMENT MORTAR MIX
 ordinary Portland cement and fine aggregate matrix is used
 The matrix constitutes 95% cement mortar & 5% wire mesh of the
composite.
 FA (sand), occupies 60 to 75% of the volume of the mortar
 Plasticizers and other admixtures are used
MIX PROPORTIONS
 Sand: cement ratio (by mass) 1.5 to 2.5
 Water: cement ratio (by mass) 0.35 to 0.60
SAND
 confirming to zone-I or Zone-II
 free from impurities
WATER
 Free from salts and organic impurities
 Minimum to achieve desired workability
 pH equal or greater than 7
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23. SKELETON STEEL
 It support the steel wire mesh
 3 to 8 mm steel rods are used
 Thickness varies from 6-20mm according to loading condition
◦ Generally mild steel or Fe 415 or Fe 500 bars are used
◦ Spacing 7.5cm to 12m
 Used to impart structural strength in case of boats, barges etc.
 Reinforcement should be free from dust, rust and other impurities.
STEEL MESH REINFORCEMENT
 Consists of galvanized steel wires of diameter 0.5 to 1.5 mm, spaced at 6 to
20mm centre to centre
 Welded wire mesh has hexagonal or rectangular openings
 Expanded-metal lath is also used Made from carbon, glass etc.
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24. PROPERTIES OF FERRO CEMENT
 It is very durable, cheap and versatile material.
 Low w/c ratio produces impermeable structures.
 Less shrinkage, and low weight.
 High tensile strength and stiffness.
 Better impact and punching shear resistance.
 Undergo large deformation before cracking or high deflection.
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25. ADVANTAGES OF FERRO-CEMENT
 It is highly versatile and can be formed into almost any shape for a wide
range of uses
 20% savings on materials and cost
 Suitability for pre-casting
 Flexibility in cutting, drilling and jointing
 Very appropriate for developing countries; labor intensive
 Good fire resistance
 Good impermeability
 Low maintenance costs
 Thin elements and light structures, reduction in self weight & Its simple
techniques require a minimum of skilled labor
 Reduction in expensive form work so economy & speed can be achieved
 Only a few simple hand tools are needed to build any structures
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26. DISADVANTAGES OF FERRO-CEMENT
 Low shear strength
 Low ductility
 Susceptibility to stress rupture failure
 It can be punctured by collision with pointed objects.
 Corrosion of the reinforcing material due to the incomplete
coverage of metal by mortar.
 It is difficult to fasten to ferrocement with bolt, screw, welding
and nail etc.
 Large no of labours required
 Tying rods and mesh together is especially tedious and time
consuming.
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27. APPLICATIONS OF FERRO CEMENT
1. Marine Applications
 Boats, fishing vessels, barges, cargo tugs, flotation buoys
 Key criteria for marine applications: light weight, impact resistance,
thickness and water tightness
2. Water supply and sanitation
 Water tanks, sedimentation tanks, swimming pool linings, well
casings, septic tanks etc.
3. Agricultural
 Grain storage bins, silos, canal linings, pipes, shells for fish and
poultry farms
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28. 4. Residential Buildings
 Houses, community centers, precast housing elements, corrugated
roofing sheets, wall panels etc.
5. Rural Energy
 Biogas digesters, biogas holders, incinerators, panels for solar energy
collectors etc.
6. Miscellaneous uses
 Mobile homes
 Kiosks
 Wind tunnel
 Silos and bins
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29. Ready Mix Concrete
“Ready mix concrete is concrete whose components are proportioned
away from the construction site for delivery to the construction site by
the truck in a ready-to-use-condition.”
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30. History
In 1909, the residents of Sneridan, Wyoming could have
witnessed the birth of Ready Mix concrete industry.
Prior to World War I, concrete was produced in stationery
plant mixer hauled to construction sites in dumps trucks.
Need for Ready Mix concrete
 Requirement for higher grades of concrete
 Correct accountability ingredients
 Rapid development of infrastructure industry
 Increased demand of concrete
 Possibility of manufacture of desired grades
 Mega project demands higher output
 Timely supply of reliable concrete
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31. Advantages Of Ready Mix Concrete
 Quality assurance
 Elimination of manual errors
 Mass production of concrete possible
 Water cement ratio maintained
 Reduced material wastage
 Labour cost saved
 Design mix as per IS standards resulting in standard deviation and
improved characteristics.
Disadvantages
 The materials are batched at a central plant, and the mixing begins at
that plant
 Generation of additional road traffic; furthermore, access roads, and
site access have to be able to carry the weight of the truck and load.
 Concrete's limited time span between mixing and going-off
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32. FIBER REINFORCED CONCRETE
Concrete containing a hydraulic cement, water , aggregate, and
discontinuous discrete fibers is called fiber reinforced concrete.
Fibers can be in form of steel fiber, glass fiber, natural fiber , synthetic
fiber.
Benefits
Main role of fibers is to bridge the cracks that develop in concrete
and increase the ductility of concrete elements.
 Improvement on Post-Cracking behavior of concrete
Imparts more resistance to Impact load
controls plastic shrinkage cracking and drying shrinkage cracking
Lowers the permeability of concrete matrix and thus reduce the
bleeding of water
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33. Factors affecting the Properties of FRC
Volume of fibers
Aspect ratio of fiber
Orientation of fiber
Relative fiber matrix stiffness
Volume of fiber
 Low volume fraction (less than 1%)
◦ Used in slab and pavement that have large exposed surface leading to high
shrinkage cracking
 Moderate volume fraction(between 1 and 2 percent)
◦ Used in Construction method such as Shortcrete & in Structures which requires
improved capacity against delamination, spalling & fatigue
 High volume fraction(greater than 2%)
◦ Used in making high performance fiber reinforced composites (HPFRC)
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34. Aspect Ratio of fiber
It is defined as ratio of length of fiber to it’s diameter (L/d).
Increase in the aspect ratio upto 75,there is increase in relative strength and
toughness.
Beyond 75 of aspect ratio there is decrease in aspect ratio and toughness.
Orientation of fibers
 Aligned in the direction of load
 Aligned in the direction perpendicular to load
 Randomly distribution of fibers
◦ It is observed that fibers aligned parallel to applied load offered
more tensile strength and toughness than randomly distributed or
perpendicular fibers.
Relative fiber matrix
Modulus of elasticity of matrix must be less than of fibers for efficient stress
transfer.
Low modulus of fibers imparts more energy absorption while high modulus fibers
imparts strength and stiffness.
Low modulus fibers e.g. Nylons and Polypropylene fibers
High modulus fibers e.g. Steel, Glass, and Carbon fibers 34G.GUNA SRVEC

35. Types of fiber used in FRC
Steel Fiber Reinforced Concrete
Polypropylene Fiber Reinforced (PFR) concrete
Glass-Fiber Reinforced Concrete
Asbestos fibers
Carbon fibers and Other Natural fibers
Steel Fiber Reinforced Concrete
Diameter Varying from 0.3-0.5 mm (IS:280-1976)
Length varying from 35-60 mm
Various shapes of steel fibers
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36. Advantage of Steel fiber
High structural strength
Reduced crack widths and control the crack widths tightly, thus improving
durability
less steel reinforcement required
Improve ductility
Reduced crack widths and control the crack widths tightly, thus improving
durability
Improve impact– and abrasion–resistance
Application of FRC in India & Abroad
More than 400 tones of Steel Fibers have been used recently in the construction
of a road overlay for a project at Mathura (UP).
A 3.9 km long district heating tunnel, caring heating pipelines from a power
plant on the island Amager into the center of Copenhagen, is lined with SFC
segments without any conventional steel bar reinforcement.
steel fibers are used without rebars to carry flexural loads is a parking garage at
Heathrow Airport. It is a structure with 10 cm thick slab.
Precast fiber reinforced concrete manhole covers and frames are being widely used in
India.
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37. GEO POLYMER CONCRETE
Geopolymer concrete has the potential to substantially curb CO2 emissions
produce a more durable infrastructure capable of design life measured in hundreds
of years
conserve hundreds of thousands of acres currently used for disposal of coal
combustion products
protect aquifers and surface bodies of fresh water via the elimination of fly ash
disposal sites.
OPC vs GEO POLYMER
Geopolymer concrete (GPC) using “fly ash”
Greater corrosion resistance,
Substantially higher fire resistance (up to 2400° F),
High compressive and tensile strengths
Rapid strength gain, and lower shrinkage.
Greenhouse gas reduction potential as much as 90 percent when compared with OPC.
Hardened cementations paste made from flyash and alkaline solution.
Combines waste products into useful product.
 Setting mechanism depends on polymerization.
Curing temp is between 60-90 degree.
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38. CONSTITUENTS
Source materials :
Alumina-silicate
Alkaline liquids
combination of sodium hydroxide (NaOH) or potassium
hydroxide (KOH) and sodium silicate or potassium silicate.
Geopolymerisation
Storage
Aggregate
Fly ash
Alkaline activator
NaOH + Na Silicate
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39. 39G.GUNA SRVEC

40. Cutting the world’s carbon. The price of fly ash is low.
Better compressive strength. Fire proof
ADVANTAGES
ADVANTAGES  Cutting the world’s carbon.
 The price of fly ash is low.
 Better compressive strength.
 Fire proof
 Low permeability.
 Eco-friendly.
APPLICATIONS Pre-cast concrete products like railway sleepers, electric power
poles, parking tiles etc.
Marine structures due to resistance against chemical attacks
Waste containments( fly ash)
HURDLES • Different source materials
• Properties of soluble silicate
• Contaminants
• Industry regulations
• New material
• Lack of awareness.
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41. SHOTCRETE TECHNOLOGY
providing quality products and services to the industry since 1979
This innovative technology of shotcrete was introduced to make the
work easier and immediate
mortar or high performance concrete conveyed through a hose and
pneumatically projected at high velocity onto a backing surface
 An acceptable way of placing cementitious material in a variety
of applications.
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42. Shotcrete, high performance product
consisting of …
+
aggregates waterCement admixture
non-alkaline accelerator
+ + +
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43. History
was invented in the early 1900s by American taxidermist Carl Akeley.
used to fill plaster models of animals.
In 1911, he was granted a patent.
Until the 1950’s, the wet-mix process was devised, only the dry-mix process
was used.
Reinforcement
Sprayed concrete is reinforced by conventional steel rods, steel
mesh, and/or fibers.
Fiber reinforcement (steel or synthetic) is also used for stabilization
in applications such as slopes or tunneling.
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44. Shotcrete vs. Conventional Concrete
conventional concrete is first placed and then compacted in the second operation.
shotcrete undergoes placement and compaction at the same time.
Shotcrete is more dense, homogeneous, strong, and waterproof .
It can be impacted onto any type or shape of surface, including vertical or overhead
areas
Classification of Shotcrete
1. Dry process 2. Wet process
Dry process:
Step1: Pre blended, dry or semi-dampened materials are placed into
shotcrete equipment and metered into a hose.
Step2: Compressed air conveys materials at high velocity to the nozzle
where the water is added.
Step3: Then the material is consolidated on receiving surface by high
impact velocity.
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45. Advantages of Dry process:
Easy start up, shutdown and clean up.
Control of materials is on site.
Nozzle man can be up to 1000ft horizontally or 500ft
vertically from the gun.
Wet process:
Step1: All ingredients, including water, are thoroughly mixed and
introduced into the shotcrete equipment.
Step 2: Wet material is pumped to the nozzle where compressed air is
introduced
Step 3: Mostly wet-process shotcreting is done with premixed mortar or
small aggregate concrete.
Advantages
Little or no formwork is required.
Cost effective method for placing concrete.
Ideal for irregular surface applications
Allows for easier material handling in areas with difficult access
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46. Rehabilitation of subway tunnels
construction of domed roofs.
Highway culvert repair and arch culvert46G.GUNA SRVEC

47. SIFCON
SIFCON is the slurry infiltrated fiber concrete.
The strength of the concrete is high with the flexural strength and is
suitable for earthquake prone areas.
The cement slurry is introduced over the steel fibers.
The coarse aggregate is omitted.
SIFCON OVER FRC
•The strength of sifcon is higher than ordinary FRC
•In FRC there is a risk of balling and clustering.
•The fiber content is limited to 2 – 5% in FRC
•The sifcon possess high flow ability and passing ability.
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48. TEST FOR SIFCON
Test For Compressive Strength
Split Tensile Strength Test
Impact Test
Flexural Strength Test
MATERIALS
 OPC 53 grade
 Coiled Steel Fiber(0.2 – 0.5 mm tk)
 Super plasticizer (PLAST-M 505)
 Ordinary sand
IMPACT TEST:
 The impact strength specimens consisted of
plates of dimension 250×250×35 mm.
 A steel ball weighing 20 N was dropped from
the height of 1 m over the specimen, which
was kept on the floor
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49. TEST FOR FLEXURAL STRENGTH
 The specimens of dimension
100×100×500 mm were cast for flexural
strength test.
 Two point loading10 was adopted on
these specimens with an effective span
of 400 mm.
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50. SPLIT TENSILE TEST:
 The specimens of dimension
150 mm diameter and 300
mm length were cast for
split tensile strength
 The loads are applied gently
for vertical cracking
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