Casting of Concrete Frames

8/12/2019 Casting of Concrete Frames

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Casting of Concrete Frames

Bungag, Jediann M.

Collo, Mikhail Hans N.

Manalo, Jomel S.

CE151P A3


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Casting

It is a manufacturing process by which a liquidmaterial is usually poured into a mold, which contains a

hollow cavity of the desired shape, and then allowed tosolidify.

Concrete Framesstructural components of a building made up of

concrete and reinforcements.


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Concrete

It is structural material consisting of a hard, chemically

inert particulate substance, known as

aggregate (usually sand and gravel), that is bonded

together by cement and water.

It is construction material that hardens to a stone like

mass


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Aggregate

Concrete Cement


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Classifications of Concrete

Reinforced Concrete

Prestressed Concrete

Precast Concrete


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Reinforced Concrete

Concrete in which steel is embedded in such a manner

that the two materials act together in resisting forces.

In reinforced concrete, the tensile strength of steel and

the compressive strength of concrete work together to

allow the member to sustain these stresses overconsiderable spans.


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Prestressed Concrete

Concrete reinforced by either by pretensioning or

posttensioning, allowing it to carry a greater load or span

a greater distance than ordinary reinforced concrete.


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Precast Concrete

Concrete cast into structural members under factory

conditions and then brought to the building site.

Precast concrete components include slabs, beams,

columns, walls, stairways, modular boxes, and even

kitchens and bathrooms with precast fixtures.


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Types of Concrete

Standard Ready-Mix Concrete

Architectural and Decorative Concrete

Rapid-setting Concrete

Fiber-reinforced Concrete

Fluid-fill Concrete

Roller Compacted Concrete


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Standard Ready-Mix Concrete

It is the most common form of concrete. It is prepared fordelivery at a concrete plant instead of mixed on the

construction site, which guarantees the quality of the

concrete.

Architectural and Decorative Concrete This type of concrete can provide a structural function, as

well as an aesthetic or decorative finish. It can offer

smooth or rough surfaces or textures, as well as a variety

or range of colors.


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Rapid-setting Concrete This concrete allows fast formwork removal, accelerated

construction sequencing, and rapid repair for such jobs as

roads and airport runways.

Fiber-reinforced Concrete Concrete designed with micro or macro fibers that can

significantly increase the ductility of concrete, making it

highly resistant to crack formation and propagation.


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Fluid Fill Concrete Fluid mortar or concrete simplifies the process of laying

pipe and cable by surrounding the pipe or cable with a

tightly packed shell that provides protection from the

elements, prevents settling, and enables crews to work

quickly.

Roller Compacted Concrete Compacted in place and cured, roller-compacted concrete

is a zero slump concrete with the abrasion resistance towithstand high velocity water.


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BeamsIt is a long, sturdy piece of squared timber or metal

spanning an opening or part of a building, usually to supportthe roof or floor above.


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FoundationsIt is the lowest load-bearing part of a building,

typically below ground level.


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ColumnsA column is an upright pillar or post. Columns may

support a roof or a beam, or they can be purely decorative.


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Shear WallsA shear wall is a wall composed of braced panels to

counter the effects of lateral load acting on a structure.


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Reinforcements

Rebar (reinforcing bar)-It is serves as the skeleton of the reinforced concrete.-Rebar is used because although concrete is very strong

in compression it is virtually without strength in tension.


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Rebar (reinforcing bar)

Metallic Reinforcing Bars Steelmost common type of rebar used in construction.

Non-metallic reinforcing bars

This type of reinforcements are usually used in building withhuge magnetic machines to become nonmagnetic buildings.

Glass - stronger than traditional concrete with the unique

ability to flex without breaking but quite costly.

Plastic

can be as strong as steel.

Woodinnovative rebar that can be used to have an

environment friendly structure.


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Types of Reinforcing Steel Bars

Welded Wire Fabric- It is made from a series of steel wires arranged at right anglesand electrically welded at all steel wires crossings.

- This is commonly used in road pavements, box culverts and

drainage structures, and small concrete canals.


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Sheet-Metal Reinforcing Bars

- Sheet-metal reinforcing is composed of annealed sheet steel

pieces bent into corrugations about 1/16 inch depth, with

holes punched at regular spacing.-It is commonly used in floor slabs, stairs and roof construction.


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Stainless Steel Reinforcing Bars- It can be used as an alternative reinforcing steel bars with

carbon steel reinforcement

- Can be a cost-effective solution in areas subject to corrosion

problems, or where repair is difficult and expensive.


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Expanded Metal and Wire Mesh Reinforcement- Expanded metal is made by shearing a sheet of steel into

parallel lines and the expanded to form a diamond shape or

square shape between each cut.

- Wire mesh reinforcement can be used on sidewalks, smallconcrete pads or walkable surfaces that do not receive high

live nor load charges.


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Reinforcements are used to surpass:

1. Deflectionthe appearance or efficiency of any part of the

structure must not be adversely affected by

deflections.

2. Crackinglocal damage due to cracking to spalling must not

affect the appearance and efficiency of the

structure.

3. Durabilitythis must be considered in terms of proposed

life of structure and its condition of exposures.


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Reinforcements are used to surpass:

4. Excessive Vibrationit may cause discomfort or alarm as well

as damage.

5. Fatigue

must be considered if cyclic loading is likely.

6. Firethis must be considered in terms of resistance to

collapse, flame penetration and heat transfer.


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Casting of Concrete Frames


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Materials needed in Casting Concrete Frames:

Concrete

Reinforcements

Forms or molder

Concrete Mixer


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The Process of Casting Concrete Frames:

Step 1: The Sale

The owner of the structure will choose a contractor.

After the contract has been signed, work can begin.


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Step 2: Site Work

Before concrete can be placed, the site needs to be prepared.

Prepare a sub base where the concrete should be placed.


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Step 3: Forming

Concrete forms are made from wood, metal or plastic, and

can range in height from 4 inches to many feet.

These forms will serves as the molder of the concrete.

Reinforcements can be prepared at this time.


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Step 4: Placement

Concrete mixer are used to mix concrete.

Liquid concrete are poured in the frame allowing it to solidify

after period of time.


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Step 5: Early Finishing

Once the concrete is placed into forms, a board is used to

screed the top surface of the concrete.

Floatsare then use to further compact the concrete.


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Step 6: Finishing

The most basic type of finish is known as a "broom finish".

A special broom is pulled across the concrete surface creating a

rough textured surface.

Other types of finishing: stamped, textured and smooth trowel


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Step 7: Curing

The curing process lasts 28 days, with the first 48 hours being

the most critical.

A liquid chemical can be applied that helps the concrete cure

slowly and evenly, which helps reduce cracks, curling, andsurface discoloration.


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Step 8: Maintenance Occasional soap and water cleaning is also advised to keep

your concrete looking its best.

Sealing and regular maintenance will also minimize the chances

from staining and discoloration caused by natural or manmade

contamination.


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Factors That Can Affect Concrete Casting Quality

Unsteady Weather

-Hot Weather

-Cold Weather

-Rainy Weather

Analysis of Condition Health and Safety


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Hot Weather Dehydration To fast dehydration will lead to cracks in the construction.

Cold Weather Hardening process will stop. we will get a weak construction with pores, cracks and

corrosion on the reinforcement.

Rainy Weather Concrete floor may have a rough surface.

That can gives us extra cost considering integrally cast andsmoothing out the surface.


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Analysis of Condition The surface of the concrete should be checked every year,

to register possible damages.

A small crack can very fast stimulate to a much biggerdamage.

Health and Safety Prevent accidents for this can be a cause of delay for

construction process.


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Large steel plates are driven under water.

It should reach the hard rock at the bottom of the water.


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The water is then pumped out from the driven steel plate.

After all the water has been pumped out, let the ground at

the bottom get dried.


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The reinforcements are then applied. The concrete is then poured inside the steel plates.


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The concrete will then get hard after a period of time.

Casting of Concrete Frames

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