REINFORCED CONCRETE DESIGN

Concrete

It is an artificial stone derived from a mixture of properly proportioned amount of hydraulic cement, fine aggregates, coarse aggregates and water, with or without admixtures.

Concrete

A mixture of Portland cement or any other hydraulic cement, fine aggregates,coarse aggregates and water, with or without admixtures.

Admixture

Is a material other than water, aggregate or hydraulic cement used as an ingredient of concrete and added to concrete before and during its mixing to modify its properties.

Accelerator

An admixture which hasten the hardening rate and/or initial setting time of concrete.

Retarder

An admixture which slows the setting rate of concrete.

Reinforced Concrete

Is a composite material in which concrete's relatively low tensile strength and ductility are countered by the inclusion of reinforcement having higher tensile strength and ductility.

Class A

All superstructures and heavily reinforced substructures. The important parts of the structure included are slabs, beams, girders, columns, arch ribs, box culverts, reinforced abutments, retaining walls, and reinforced footings.

Class B

Footings, pedestals, massive pier shafts, pipe bedding, and gravity walls, unreinforced or with only a small amount of reinforcement.

Class C

Thin reinforced sections, railings, precast R.C. piles and cribbingand for filler in steel grid floors,

Class P

Prestressed concrete structures and members.

Seal

Concrete deposited in water.

Slump Test

Measurement of concrete workability, or fluidity. It's an indirect measurement of concrete consistency or stiffness.

Fine Aggregates

It shall consist of natural sand, stone screenings or other inert materials with similar characteristics, or combinations thereof, having hard, strong and durable particles. Fine aggregate from different sources of supply shall not be mixed or stored in the same pile nor used alternately in the same class of concrete without the approval of the Engineer. |

Coarse Aggregates

It shall consist of crushed stone, gravel, blast furnace slag, or other approved inert materials (coralline or dolomites) of similar characteristics, or combinations thereof, having hard, strong, durable pieces and free from any adherent coatings.

Balance Section

The steel provided in the beam is such that both concrete and steel reach the limiting values of strain simultaneously.

Under Reinforced Section

The steel provided in the beam is such that steel reach the limiting values of strain prior to concrete. This results in yielding of the steel and the steel could yield till it attains the ultimate strain at which point it breaks.

Over Reinforced Section

The steel provided in the beam is such that concretereach the limiting values of strain prior to steel. This results in breaking of concrete and since now there is no concrete present to take the compression the beam fails suddenly.

Singly Reinforced Beam

Is one in which the main reinforcement is provided only in the tension zone and also here the ultimate bending moment is less than the limiting bending moment.

Doubly Reinforced Beam

Occasionally, beams are restricted by space or aesthetic requirements to such extent the compression concrete should be reinforced with steel to carry compression.

T-Beam

Reinforced concrete floor usually consist of slabs and beams, which are placed or poured monolithically. In this effect, the beam will have an extra width at the top (that is under compression) cajed flanges.

Shear Reinforcements

Another type of beam failure other than bending failure is shear failure shear failures are very dangerous especially if it happens before flexures failure because they can occur without warning.

Development Length

Bar development length or Ld is the embedment necessary to assure that the bar can be stressed to its yield point with some reserved to insure member toughness.

200 × 300 mm

Minimum cross-section of a column

60000 mm²

Minimum Gross Area of a column

10mm

Longitudinal bars with 32mm or smaller

12mm

Longitudinal bars with 36mm or larger and for bundled Longitudinal bars.

25mm

Minimum Spacing of Spiral

75mm

Maximum Spacing of Spiral

Bearing Walls

A structural wall that supports the weight of the building's structure above it, including floors, roof, and any elements attached to it.

Exterior Wall

Any wall or element of a wall, or any member or any members, that defines the exterior boundaries or courts of a building and that has a slope of 60 degrees or greater with the horizontal plane.

Parapet Wall

Part of any wall entirely above the roof line.

Retaining Wall

A wall designed to resist the lateral displacement of soil or other materials.

Shear Wall

Is a wall designed to resist lateral forces parallel to the place of the wall.