presentation to concrete structures

7/25/2019 Presentation to concrete structures

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PRESENTATION

REINFORCED CONCRETE

By Dr :Samy Akil Fawzy Ph.D. Concrete Structures.


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Reinforced Concrete structures may be:

1-Buidings

2-Tanks


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3-Bridges

4-Tunnels

5-Silos

6-Sheds & Halls


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7-Towers

8-Airports

9-Dams

10-Retaining walls.

11-chimenys


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In order to construct any concrete structure we

have to study the following items:

1-The materialsused in constructionSteel reinforcement Concrete or others.

2-The expectedloadson the structure.

Wind load- Seismic loads Dead or live loads

3-Thestraining actionsaffecting the structure

As Bending moment Shearing force & Normal force.


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Concrete structures are divided into 4 main elements:

1-Slab & Stairs

As Solid slab ,Hollow block ,Flat slab ,Paneled beam

precast slab ,Hollow core slab ,Double Tee.

2-Beams

Either cast in situ or Precast beams and can be used a steel joist instead

of the concrete beam.

3-Columns and Walls

Columnscan be of different shapes and sizes.

Wallscan be shear walls or wall cores

4-Footings & Retaining walls.

Footingsas isolated , combined ,strap, strip, piles , casions.Tie beams or smelles.

It is used to tie the whole building to act together if differential

settlement might occur to the soil and also it can be used in an upper

level to carry walls as to decrease the height of bricks in the ground level.

Retaining wallsact as a support for soil earth pressure.


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The Design of any structure element is the calculation of the needed

dimension & inclusion of steel reinforcement in order to resist the

straining actions which occur on the structure.

Slabs

Beams

Columns

Footing

Design

Concretedimension

Quantity

of steel.

Details of

Steel.


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Reinforced Concrete consists of:

Cement

GravelSand

Water

Admixtures

Strengthen by steel reinforcement.


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Concrete:Concrete has a high compressive strength and low tensile

strength it might be about one tenth of the compressive

strength.

The low tensile strength of concrete and ductility are

enhanced by the inclusion of reinforcement having a high

tensile strength and increasing the ductility of theconcrete element.

Reinforcement are generally designed to resist the tensile

stress in the region of the cracked concrete.


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Building Types

1-Skelton Type: The loads

are transferred from theSlabs to beams and the

columns carry the beams.

The loads from the columns

are carried by the reinforced

Footings.

2-Wall Bearing Type:

The old building type were the loads of the slabs are carried by beams

Which are above each wall, and the loads of the beams are transferred

to the bearing wall below(not less than 1 brick) to the footing below

either reinforced strip footing or plain concrete strip footing.

Wall

Footing

Slab R.C Beam


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The Wall bearing type ,the bricks starts at the

strip footings or R.C. smelles with a thickness

not less than 520 mm (2 bricks) and decreases

in thickness as we go upward so that the final

thickness of the wall bearing wont be less

than 250 mm (1 brick).

When the wall carry more slabs the downward

thickness of the wall will depend on the loads

above but wont be less than 520mm as

mentioned before.

Not less than 520 mm

Not less than 250

mm-Wall Bearing Type


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Skelton Type:The loads in the Skelton type building transfer from an

element to another till it reaches the ground.

1-Slab & Stairs

As Solid slab ,Hollow block ,Flat slab ,Paneled beam

precast slab ,Hollow core slab ,Double Tee.

2-Beams

Either cast insitu or Precast beams and can be used a steel

joist instead of the concrete beam.3-Columns

Columns can be of different shapes and sizes.

3-Walls

Walls can be shear walls or wall cores

4-Footings

Footings as isolated , combined ,strap, strip, piles , casions.4-Tie beams & Smelles

It is used to tie the whole building to act together if

differential settlement might occur to the soil and also it can

be used in an upper level to carry walls as to decrease the

height of bricks in the ground level.

4-Retaining walls.


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We will focus upon the slabs

The Slabs

Concrete slab is a common structural element of modern buildings

and used in the construction of floors and ceilings.

Slabs are carried by columns and beams

Reinforced concrete slabs typically ranges between 100 mm -500

mm in thickness.

The reinforced concrete slab depends upon the area carried and the

short span in fact for the serviceability requirements.

The choice of type of the slab depends on many factors the most

important is the economy of construction


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Solid Slabs might be

A-One way slab

B-Two way slab

C-Cantilever slab

Solid Slab


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1. ordinary flat slab

2. Flat slab with Drop panel only

3. Flat slab with Column Head only

4. Flat slab with Drop panel &Column Head

Flat Slab

ll bl kSlb


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Hollow block Slab

W ffl RbbdSlb


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Waffle or Ribbed Slab

P ldb


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Paneled beam

Slab


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Concrete Structures are affected by some kind of loading

as:

1-Dead load2-Live load

3-Wind load especially in towers

4-Earthquake loading

5-differntial settlement

6-temperature loading

7-braking force8-lateral shock in cranes

9-water and earth pressure

10-impact load


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Design of Reinforced Concrete members

1-Limit State design Method)Ultimate strength limitstate),(stability limit state),(Serviceability limit state).

2-Elastic (working Stress) Design Method


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Thank You for your attention

presentation to concrete structures

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