UNIT II

CONCRETE TECHNOLOGY
DURABILITY AND MIX DESIGN, PRODUCTION AND PLACEMENT OF CONCRETE INCLUDING MECHANIZATION

SUBMITTED BY-
• (04) SHARAYU KALE

• (05) SHRUSHTI KOKATE

• (06) KUNJAN LADDHA

CONCRETE TECHNOLOGY

PRESENTED BY –
KUNJAN DINESH LADDHA
INTRODUCTION

Concrete is one of the most commonly used building materials.

► Concrete is a composite material made from several readily available

constituents (aggregates, sand, cement, water).

► The cement and water form a paste or gel which coats the sand and
aggregate.

► Concrete is a versatile material that can easily be mixed to meet a

variety of special needs and formed to virtually any shape.

► Concrete's versatility, durability, sustainability, and economy have made

it the world's most widely used construction material.
CONSTITUENTS OF CONCRETE

Concrete is a mixture of cement ( 9 -15\%), water ( 15 -16\%) , fine aggregate (sand, 25 -30\%) coarse aggregate (gravel
or crushed rocks, 30 -45\%) air ( 2 -6\%) and chemical admixtures in which the cement and water have hardened by a
chemical reaction - hydration - to bind the nearly (non-reacting) aggregate.

9-15% CEMENT 15-16% WATER 25-30% FINE AGGREGATE 30-45% COARSE AGGREGATE

PASTE
MORTAR
CONCRETE
CEMENT FINE AGGREGATE (SAND)

A cement is a binder, a substance used for This component can be natural sand or crushed stone,
construction that sets, hardens, and adheres to other and represents particles smaller than 4.0 mm.
materials to bind them together. Generally accounts for 25%-30% of the mixture.
► Cement contains limestone, clay, rock and iron ore
blended and heated to 1200 to 1500 C. ► For the purpose of construction Pit sand, River sand,
Sea sand, and manufactured sand are used in which pit
►The resulting product "clinker" is then ground to sand is most common for concrete.
the consistency of powder. Gypsum is added to
control setting time.
COURSE AGGREGATE WATER

• May be either gravel or crushed stone comprised • Mixing water is the quantity of water that comes in
of particles greater than 4mm. contact with cement, impacts slump of concrete and is
used to determine the water to cementitious materials
• Makes up 30%-45% of the mixture. These are ratio (w/cm) of the concrete mixture.
Rounded, Angular, Flaky and Elongated in shape.
Round aggregate give better workability and • Strength and durability of concrete is controlled to a
angular aggregate is very suitable for high large extent by its w/cm.
strength concrete.
 ADMIXTURES

Admixtures are the materials added to alter the properties of concrete,

it includes:

• Air entraining admixtures: add microscopic air bubbles to the

concrete, enhancing its resistance to freeze/thaw cycles and makes
the concrete easier to finish.
• Set accelerators: speed the set-time of the mixture, enabling
finishing operations to begin sooner, useful during cold weather
pours.
• Set retarders: have the opposite effect, slowing the set and enabling
delivery to distant sites and finishing during hot weather.
• Water reducers: used to reduce the amount of water required to
produce a given slump. They also provide a ball bearing effect, making
the concrete easier to finish, and produce better cement hydration.
DIFFERENT TYPES OF CONCRETE
A brief account of different types of concrete is given below.

• Plain or Ordinary Concrete - It is mostly used in the construction of pavements and in buildings, where very high
tensile strength is not required.

• Lightweight Concrete – Is used depending upon their composition, for thermal insulation, for protecting steel
structures, they are also used in long span bridge decks, and even as building blocks.

• High-Density Concrete - They are mostly used in atomic power plants and other similar structures because it provides
good protection from all type of radiations.

• Reinforced Concrete - The resulting material (RCC) is capable of bearing all types of stress in any type of construction.
RCC is the most important concrete type.

• Precast Concrete - This term refers to numerous types of concrete shapes that are cast into molds either in a
factory or at the site.

• Prestressed Concrete - It is a special type of reinforced concrete in which the reinforcement bars are tensioned before
being embedded in the concrete.
PROPERTIES OF CONCRETE

 Compressive Strength
 Tensile Strength
 Workability
 Durability
 Segregation
 Bleeding
 Modulus of Elasticity
 Poisson Ratio
 Creep
 Shrinkage
 Harshness
ADVANTAGES OF CONCRETE

Concrete is so integral to our communities because it is the only building material that cost-
effectively delivers:

• The lowest carbon footprint for a structure or pavement over its lifecycle.
• Unparalleled strength, durability, longevity and resilience.
• Maximized energy efficiency via thermal mass.
• Durability in any environment.
• A building material that doesn't burn, rust or rot.
• Safety and security.
• Versatility - It can be molded into any shape, colour or pattern imaginable.
• No off-gas.
USES OF CONCRETE
USES OF CONCRETE
TESTS FOR CONCRETE
 MANUFACTURING OF CONCRETE

STAGES OF CONCRETE PRODUCTION :

BATCHING MIXING TRANSPORTING PLACING COMPACTING FINISHING CURING

1. Batching of concrete:
Batching is the process of measuring of material required for concrete mix by weight or volume.
Batching is done by two approaches.

•Volume batching
•Weight batching

i. Volume batching:

Volume batching is done by a typical gauge box that is known as

“farmas” in the field. The volume of farma is 0.035m3 which is
similar to the volume of 1 bag of cement.
Farma is made of timber, steel or plastic materials.

ii. Weight batching:

Weight batching is done manually or semi-automatically, or fully

automatically. Mostly it is used in Ready mix concrete plants.
This type of batching is mostly used for large construction.
2. Mixing of concrete:

Mixing is necessary to make homogeneous concrete. To obtain a good quality of concrete, it is necessary to
do proper mixing of concrete ingredients. The mixing of concrete depends on the types of mixing.

Generally mixing is done by three ways.

•Hand mixing
•Machine mixing
•Ready-mix concrete

Three types of machineries used for

mixing of concrete.
•Tilting type
•Non-tilting type
•Reversing type
3. Transportation of concrete:

wheel borrow Bucket & Belt conveyors

Ropeway Skip & Hoist

Mortar pan Transit mixer Pumps &

pipelines
4. Placing of concrete:
Placing of concrete is the process of deposition of concrete in its required position.
Placing of concrete under water is done by various methods.
•Tremie method
•Bagged method
•Bottom dump method, etc.
5. Compaction of concrete:
Compaction of concrete is a process in which concrete is
compacted by various methods to remove entrapped air from
the concrete and increase the strength of concrete.
By doing compaction of concrete, concrete becomes dense,
impermeable due to that the durability of concrete increases.

Compaction of concrete done by two ways.

•Hand compaction
•Mechanical compaction
i. Hand compaction: ii. Mechanical compaction:
•Roding •Needle vibrator
•Ramming •Form vibrator
•Tamping •Table vibrator
•Surface vibrator
6. Curing of concrete:
Curing of concrete is defined as a process to maintain temperature and moisture of concrete during the
hydration process of cement due to that hydration of cement completed and concrete gains maximum
strength.
Curing of concrete done by various methods that are given below.
•Water curing
•Membrane curing
•Steam curing
•Other techniques
READY MIX CONCRETE

PRESENTED BY –
SHRUSHTI KOKATE
READY MIX CONCRETE
RMC
 RMC IN INDIA:
In India RMC was first initially was used in 1950 during the construction sites of Dams like Bhakra Nangal, Koyna. At the
construction the transportation of concrete is done by either manually or mechanically using ropeways & buckets or
conveyor systems.

General introduction:
• Ready Mix Concrete (RMC) is a specialized material in which the cement aggregates and other ingredients are
weigh-batched at a plant in a central mixer or truck mixer, before delivery to the construction site in a condition
ready for placing by the builder.
• Thus, `fresh' concrete is manufactured in a plant away from the construction site and transported within the
requisite journey time.
• The RMC supplier Provides 2 services first of processing the materials for making fresh concrete & secondly, of
transporting the product within the short time.
ADVANTAGE OF RMC
• RMC is preferred to on-site concrete mixing because of the precision of the mixture and reduced worksite confusion.
• It facilitates speedy construction through programmed delivery at site and mechanized operation with consequent
economy.
• It also decreases labour charges, site supervising cost & project time resulting in savings.
• Proper control & economy in use of raw material results in savings of natural resources.
• It assures consistent quality through accurate computerised control.

DISADVANTAGE OF RMC
• The materials are batched at a central plant, and the mixing begins at that plant, so the traveling time from the plant to
the site is critical over longer distances.
• Access roads & site access have to be able to carry the weight of the trucks and load concrete is approx. 2.5 tonne
per meter cube.
• Concrete’s limited time span between mixing & going off means that ready mix should be placed within 2 hrs.
 READY MIX CONCRETE VS. STANDARD CONCRETE
• Centralized concrete batching plant can serve a wide area. Site-mix trucks can serve an even larger area including
remote locations that standard trucks can not.
• The plants are located in areas zoned for industrial use & yet the delivery trucks can service residential districts or
inner cities. Site-mix trucks have the same capabilities.
• Better quality concrete is produced. Site mix can produce higher compression strength with less water than standard
batching methods

MIXING PROCESS
Thorough mixing of the materials is essential for the production of uniform concrete. The mixing should ensure that the
mass becomes homogeneous, uniform in color and consistency. There are three methods adopted for mixing Ready Mix
Concrete. Following are the three types of mixing process of RMC
1. Transit Mixed (or "truck-mixed") Concrete
2. Shrink Mixed Concrete
3. Central Mixed Concrete
CENTRALLY MIX
In the case of the centrally mixed type, the drum carrying the concrete revolves
slowly so as to prevent the mixed concrete from "segregation“ and prevent its
stiffening due to initial set. However, in the case of the truck-mixed concrete, the
batched materials (sand, gravel and cement) are carried and water is added just at
the time of mixing. In this case the cement remains in contact with wet or moist
materials & this phase cannot exceed the permissible period, which is normally 90
mins.
The use of RMC is facilitated through a truck mounted “boom placer” that can pump
the product for ready use at multi storied construction sites. A ‘boom placer’ can
pimp the concrete upto 80 meters.

TRANSIT MIXING
It is delivered to the worksite, often in transit mixers capable of mixing the
ingredients of the concrete just before the delivery of batch.
This results in a precise mixture, allowing specialty concrete mixtures to be
developed and implemented on construction sites.
Concrete or mortar moistened & mixed in truck mixer enroute to or at the
work site.
Storage of Materials
i) Cement
ii) Water
iii) Aggregates

Time in Transport
The general requirement is that concrete shall be discharged from the truck mixer within 2 hours of the time of loading.
However, longer period may be permitted if retarding admixtures are used or in cool humid weather or when chilled
concrete is produced

SAMPLING AND TESTING OF READY-MIXED CONCRETE (As per IS

4926-2003)
For the assessment of compliance of ready-mixed concrete, the point and the time of sampling shall beat the discharge
from the producer's delivery vehicle or from the mixer to the site or when delivered into the purchaser's vehicle.
 VOLUMETRIC CONCRETE MIXER
 A volumetric concrete mixer (also known as volumetric mobile mixer and metered
concrete truck) is a truck that contains concrete ingredient materials and water to be
mixed on the truck at the job site to make and deliver concrete according to the
amount needed.

 The mixer is a mixing device that measures the raw materials using volume rather than
weight. The volumetric mixer blends the concrete mixture using an auger or a paddle
or a drum device to mix the ingredients with water. The volumetric mixing process
starts with a batch metering system that allows the volume of raw materials to be
measured prior to entering the mixing chamber. This process can be as simple as using a
measured bucket, to highly sophisticated and computerized batch plants that feed the
correct volume.
 As an alternative to ready-mix concrete, volumetric mobile mixers may be used to
provide metered concrete services. The volumetric mobile mixer is a truck that contains
concrete ingredient materials and water to be mixed on the truck at the job site to
make and deliver concrete according to the amount needed. The on-truck mixing at the
job site eliminates the problems of ready-mix concrete such as delays that can cause
the pre-mixed concrete to become unusable. This is a hybrid approach between ready-
mix concrete and traditional on-site mixing.
• TRANSIT MIXED (OR "TRUCK-MIXED") CONCRETE

In transit-mixed concrete, also called truck mixed or dry-batched, all of

the raw ingredients are charged directly in the truck mixer. Most or all
water is usually batched at the plant. The Versatility of Ready Mix
Concrete. Concrete mixed at the job site:- While traveling to the
jobsite the drum is turned at agitating speed (slow speed). After arriving
at the job site, the concrete is completely mixed. Concrete mixed in the
yard:- The drum is turned at highspeed or 12-15 rpm for 50 revolutions.
This allows a quick check of the batch. The concrete is then agitated
slowly while driving to the job site. Concrete mixed in transit:- The
drum is turned at medium speed or about 8 rpm for 70 revolutions
while driving to the job site. The drum is then slowed to agitating speed.
STANDARD READY-MIX CONCRETE VS. SITE-MIX CONCRETE

 A centralized concrete batching plant can serve a wide

area. Site-mix trucks can serve an even larger area including
remote locations that standard trucks can not.
 The plants are located in areas zoned for industrial use, and
yet the delivery trucks can service residential districts or
inner cities. Site-mix trucks have the same capabilities.
 Better quality concrete is produced. Site mix can produce
higher compression strength with less water than standard
batching methods.
TABLE 1 ASSUMED STANDARD DEVIATION

Grade of Concrete Assumed Standar

Deviation nn N/sq.mm
 M 10 3.5
 M 15
 M 20 4.0
 M 25
 M 30 5.0
 M 35
 M 40
 M 45
 M 50
ADMIXTURE:

• A substance added to the basic concrete mixture to alter one or

more properties of the concrete; i.e. fibrous materials for reinforcing,
water repellent treatments, and coloring compounds.
• Air-entraining admixtures (mainly used in concrete exposed to
freezing and thawing cycles)
• Water-reducing admixtures, plasticizers (reduce the dosage of water
while maintaining the workability)
• Retarding admixtures (mainly used in hot weather to retard the
reaction of hydration)
• Accelerating admixtures (mainly used in cold weather to accelerate
the reaction of hydration)
• Super plasticizer or high range water-reducer (significantly reduce
the dosage of water while maintaining the workability)
• Miscellaneous admixtures such as corrosion inhibiting, shrinkage
reducing, coloring, pumping etc.
SPECIAL CONCRETE

PRESENTED BY –
SHARAYU KALE
SPECIAL CONCRETE
HIGH PERFORMANCE CONCRETE, SELF-COMPACTING CONCRETE, PERVIOUS CONCRETE, AESTHETIC CONCRETE
INTRODUCTION
 The concrete is a macro content that is made by blending cement, sand & coarse aggregate with water.
 The strength of the structure depends on the properties of the concrete we use.
 If we need to build special structures such as power plants, offshore buildings, docks, airports, we need
special concrete that has a distinct set of properties.
 The concrete which is made unique to withstand any specific aggressive condition or situation is
known as special concrete. This will be attained by either changing the core ingredients or by the
manufacturing process or by the combination of both.

ADVANTAGES
• It extends the life of the structure by fighting an aggressive situation.
• Both compressive and tensile strength of concrete is high.
• It produces high strength, so the possibility of structural failure is very less.
 DIFFERENCE BETWEEN ORDINARY AND SPECIAL CONCRETE
Ordinary Concrete Special Concrete

Economical Expensive
Strength & durability is very high under aggressive
Strength & durability is low.
conditions.
The formal method used to produce the special
A High technique used.
concrete.

Mostly natural resources are used to make the Some special admixtures & other materials are used to
concrete. make the concrete.

It is used in the construction of nuclear plants, power

It is used in typical construction works.
plants & radiation protection structures.

The water cement ratio is less using of admixture &

The water cement ratio ranges from 0.4 to 0.55
superplasticizer.
TYPES OF SPECIAL CONCRETE
• Ferrocement Concrete
• Fibre Reinforced Concrete
• Steel Fibre Reinforced Concrete
• Glass Fibre Reinforced Concrete

• Polymer Impregnated Concrete

Ferrocement Concrete Steel Fibre Reinforced Concrete
• Polymer Cement Concrete
• Polymer Concrete

• Superplastized Concrete
• Ultra-High Strength Concrete
• Sulphur Impregnated Concrete
• Self-compacting Concrete
Sulphur Impregnated Concrete Glass Fibre
SELF COMPACTING CONCRETE
 SELF-COMPACTING CONCRETE

INTRODUCTION
 The self-compacting concrete is used where the reinforcement layers are very congested and not possible
to give compaction by the vibrator.
 The SSC concrete will settle properly without bleeding & segregation in the formwork without any external
force of compaction
 The workability of concrete is very high, and the admixture will be used to reduce the water content for
cracks happening by air voids.
 The aggregate sizes are not more than 20mm which does not affect the workability of concrete.
SELF-COMPACTING CONCRETE
MATERIALS
 Cement-Ordinary Portland cement either 43 or 53 grade cement can be used.
 Aggregates- The size of the aggregates used for SCC design is limited to 20mm. If the reinforcement employed for the
structure is congested, the aggregate size used can be in the range 10 to 12mm. Graded aggregates either round or
cubical shape are used.
 Water-The quality of water used is same that followed for reinforced concrete and prestressed concrete construction.
 Mineral Admixtures- Can be used as per requirements. GGBS FLY ASH
Ground Granulated Blast Furnace Slag (GGBS)
Fly ash
Silica Fumes
Stone Powder
 Chemical Admixtures- In order to improve the freeze and thaw resistance of the concrete structure, air adjusting
agents are used.To control the setting time, retarders are used.
SELF-COMPACTING CONCRETE
ADVANTAGES
1. SCC enables freedom in designing concrete structures
2. The SCC construction is faster
3. The problems associated with vibration is eliminated
4. The concrete is placed with ease, which results in large cost saving
5. The quality of the construction is increase

DISADVANTAGES
1. The cost of construction is costlier than the conventional concrete construction
2. The use of designed mix will require more trial batches and lab tests
3. The measurement and monitoring must be more precise.
4. The material selection for SCC is more strict
SELF-COMPACTING CONCRETE
APPLICATIONS
1. SCC is used for repairs, restoration and renewal construction
2. Highly stable and durable retaining walls are constructed with the help of SCC
3. SCC is employed in the construction of raft and pile foundations
HIGH PERFORMANCE CONCRETE
 HIGH PERFORMANCE CONCRETE

INTRODUCTION
 A concrete mixture which has high workability, high strength, high modulus of physical property, high density, high
dimensional stability, low permeability and resistance to chemical attack is generally said to be high performance
concrete.
 The composition of high-performance concrete is almost the same as that of conventional cement concrete.
However, it has many features such as high strength, smooth fracture surface, low permeability, discontinuous pore,
etc. which are different from those of ordinary concrete.
 This is due to low water to cementitious material ratio, and the presence of cementitious materials and
chemical admixtures.
 Curing of HPC is much important.
HIGH PERFORMANCE CONCRETE

MATERIALS
 Cement- Cement with low C3A (Tricalcium aluminate) is the most desired type of cement to produce high-
performance concrete because the C3A creates incompatibility of cement with a superplasticizer.
 Aggregates- Both river sand and crushed stones can be used. The selection of coarse aggregate is crucial .
 Water
 Mineral Admixtures- Can be used as per requirements.
Ground Granulated Blast Furnace Slag (GGBS
Fly ash
Silica Fumes
Stone Powder
 Chemical Admixtures- improves the workability of the concrete mix by increasing the efficiency of the cement
paste, which results in decreased water requirement.
HIGH PERFORMANCE CONCRETE

ADVANTAGES APPLICATIONS
1. Speed of construction.
• Bridges
2. Economical material in Terms of time and money.
• High rise buildings
3. Higher seismic resistance.
• Tunnels
4. Improved durability.
• Pavements
5. High tensile strength.
6. Reduced maintenance cost • Nuclear structures

DISADVANTAGES
1. An extended quality control, as each and every aspect has to be checked as this type of concrete is widely used in the
construction of mega structures.
2. Cost is high due to used of various admixtures and high quality materials.
PERVIOUS CONCRETE
 PERVIOUS CONCRETE

INTRODUCTION
 Pervious concrete has large voids that allow water or air to pass through it. The pores size varies from 2 to 8 mm,
has a void content of 18 to 35 percent.
 Pervious concrete is often used in pavements.
 Porous concrete helps recharge groundwater, minimizing stormwater by enabling it to seep into the ground.

MATERIALS
 Cement- Ordinary Portland cement
 Aggregates- Coarse aggregates (19mm-9.5mm)Water(free from salts & impurities)
 Water
 Supplementary cementitious materials (SCM) such as fly ash, pozzolana & blast furnace slag are also used
PERVIOUS CONCRETE

ADVANTAGES
APPLICATIONS
1. Ground water Recharge
• Road pavement,
2. Reduction In Surface Run-off
• Parking areas,
3. Filtering of storm water
• Areas with light traffic,
DISADVANTAGES • Pedestrian walkways,
1. Can not be used on pavements with heavy traffic flow. • External Walls,
2. Requires longer curing time.
3. Requires specialized construction practice.
4. Conventional concrete tests like slump test and compaction factor test are not applicable.
5. Special design considerations need to be implemented.
6. Requires regular cleaning to maintain its permeability.
ALTERNATIVE AGGREGATES
AESTHETIC CONCRETE
 CONCRETE STAIN SWIRL CONCRETE FINISH POLISHED CONCRETE FINISH

INTRODUCTION
 Concrete finish refers to the final surface treatment applied to a concrete surface after it has been poured and set.
 This process helps to enhance the appearance and durability of the concrete and can include techniques such as
smoothing, texturing, and coloring.
 Common types of concrete finishes include broom finish, exposed aggregate finish, and smooth-troweled finish.
 The specific finish chosen depends on the proposed use of the concrete, the design aesthetic desired, and the budget.

SALT FINISH STAMPED FINISH CONCRETE COLOURED FINISH

 TROWELING FINISH BROOM CONCRETE SLAB FINISH EXPOSED AGGREGATE FINISH

SALT FINISH STAMPED FINISH CONCRETE COLOURED FINISH

 ALTERNATIVE AGGREGATES

INTRODUCTION
 With the significant increase in construction work, the demand for
concrete is growing day by day.
 Peak demands are causing a scarcity of raw materials. Besides, studies
show that concrete production involves about 10% of the total
greenhouse gas emissions.
 Considering the raw materials depletion and environmental degradation,
sustainable aggregate alternatives became a terrible need.
 Thus the need of Alternative for Aggregate came into need.
 CRUSHED RUBBER AGGREGATE COCONUT SHELL E-WASTE PARTIAL REPLACEMENT

PLASTIC WASTE PARTIAL PARTIAL REPLACEMENTOF QUARRY

CONSTRUCTION WASTE REPLACEMENT DUST
THANK YOU