concrete is the key element of the civil engineering.It will be more beneficial to the first year student who want to learn basic about the concrete.How concrete originated and types of it all the related thing are described in this power point presentation.

1. Research Methodology and Inteactual Property Right
CONCRETE
Marwadi Education Foundation, Rajkot 1
Presented by-
Dhrumil Pandya (1807020001)
STRUCTURAL ENGINEERING (M.E.)
(2018-2020)
Guided by
Dr. Sidharth Shah
Head of Department
Civil Engineering

2. Concrete
• The word concrete comes from the Latin word "concretus". Which
means compact.
• Now a days concrete is most common and necessary things in our life.
It’s a composite material composed of coarse aggregate bonded
together with a fluid cement which hardens over time.

4. • Concrete is a versatile material that can easily be mixed to
meet a variety of special needs and formed to virtually any
shape.
• It can be placed or molded into virtually any shape and
reproduce any surface texture.
• The most widely used construction material in the world.
• The ready-mix concrete producer has made concrete an
appropriate construction material for many applications.

5. History of concrete
• The history of cementing materials together goes back to the time
when prehistoric man prepare his cave to build shelter.
• He used mud and clay to fill the gap between stone. To keep out
the wind and cold.
• Later the Assyrians and Babylonians used clay as their bonding
substance and straw to make a shape.
• The Egyptians used lime and gypsum and crushed stone to create
a material that would harden even better

6. • Then the Roman made cement and they learn how to use volcanic
ash. After that they built lots of structure like Pantheon,
Colosseum, Trajan's Column.
• After the Roman Empire collapsed, use of concrete became rare
until the technology was redeveloped in the mid 18th century.

7. Basic ingredients of modern concrete
• Binding materials: lime, cement.
• Fine aggregates: sand, surkhi etc.
• Coarse aggregates: crushed stones, broken bricks, gravel and so
on.
• Water

8. Factors affecting strength of modern concrete
• Water/cement ratio
• Aggregate/cement ratio
• Grading of aggregate
• Size , shape and surface texture of aggregate
• Maximum sixe of aggregate
• Efficiency of curing
• Temperature at which concrete is hardened

9. Classifications of concrete
Based on unit weight
• Ultra light concrete <1,200 kg/m3
• Lightweight concrete 1200- 1,800 kg/m3
• Normal-weight concrete ~ 2,400 kg/m3
• Heavyweight concrete > 3,200 kg/m3

10. Based on strength (of cylindrical sample)
• Low-strength concrete < 20 MPa compressive strength
• Moderate-strength concrete 20 -50 MPa compressive strength
• High-strength concrete 50 - 200 MPa compressive strength
• Ultra high-strength concrete > 200 MPa compressive strength
Based on additives:
• Normal concrete
• Fiber reinforced concrete
• Polymer concrete

11. Workability of concrete
• Workability implies the ease with which a concrete mix can
handled from the mixer to its finally compacted shape. Factors
affecting workability:
• Water cement ratio
• Aggregates (shape, texture, size)
• Fineness of cement
• Time and temperature
• Admixture

12. Measurement of workability
• Slump test
• Compacting factor test
• Flow test
• Kelly ball test
• Vee Bee consistometer test

13. SOME IMPORTANT TERMS
Segregation (separation)
• Segregation is when the aggregates separate from the rest of the concrete.
This causes weakening and excessive curling and shrinkage. Some of the
ways to avoid segregation include:
• Placing the concrete as close as possible to its final position.
• Do not drop from higher that 2-3 feet.
• Avoid high slumps.
• Do not move the concrete with a vibrator.

14. Bleeding (water concentration)
• Bleeding means the concentration of water at certain portions of
the concrete.
• The locations with increased water concentration are concrete
surface, bottom of large aggregate and bottom of reinforcing steel.
• Bleed water trapped under aggregates or steel lead to the
formation of weak and porous zones, within which micro cracks
can easily form and propagate

15. Compacting concrete
• After placing the concrete it has to be compacted to remove voids.
• This can be achieved by overfilling and physically tamping the concrete into
place, or by using mechanical vibration.
• When pre-cast elements are made, the concrete is poured into forms which
are vibrated as a whole on tables.
• Surface vibrators are only used for concrete which has a maximum depth of
150mm for floors or roads

16. Curing Concrete
• Concrete hardens because of hydration, the chemical reaction
between Portland cement and water.
• As long as the temperatures are favourable and moisture is present
to hydrate the cement, the following properties of concrete
improve with age: durability (resistance to freezing and thawing),
strength, water tightness, wear resistance, and volume stability

17. Advantages of Concrete
• Ingredients of concrete are easily available in most of the places.
• Unlike natural stones, concrete is free from defects and flaws.
• Concrete can be manufactured to desired strength with an
economy.
• The durability of concrete is very high.
• It can be cast to any desired shape.
• The casting of concrete can be done in the working site which
makes it economical.

18. • Maintenance cost of concrete is almost negligible.
• The deterioration of concrete is not appreciable with age.
• Concrete makes a building fire-safe due to its non combustible
nature.
• Concrete can withstand high temperatures.
• Concrete is resistant to wind and water. Therefore, it is very useful
in storm shelters.
• As a soundproofing material cinder concrete could be used.

19. Disadvantages of Concrete
• Compared to other binding materials, the tensile strength of
concrete is relatively low.
• Concrete is less ductile.
• The weight of compared is high compared to its strength.
• Concrete may contains soluble salts. Soluble salts cause
efflorescence.