Everything about Rebars
Rebar is the short version used for reinforcing bar which is a steel bar used as a tension device in concrete structures and reinforced masonry structures. It helps to hold the concrete in tension and strengthens the construction. Since the 15th centuries, rebar is used in the construction sector.
Uses In Concrete And Masonry:
Concrete is a material which is weak in tension and strong in compression. In order to compensate this imbalance, rebar is cast into it to carry the tensile loads. The uses of rebars in concrete are ::
Ø It is used to guarantee the resistance which is required by the structure and also supports the design loads.
Ø Rebar is used to hold other steel bars in the correct position.
Ø It is also being used in the concrete for durability and other aesthetic reasons.
In masonry units like blocks and bricks, the rebars are accommodated within the voids which are known as reinforced masonry. It is very important that the reinforcing steel is placed properly in order to ensure the right amount of concrete cover. This cover protects the reinforcing steel from corrosion.
Placing Of Rebar:
Rebar cages are either fabricated on or off the project site with the help of shears or hydraulic benders. The rebars in the cages are connected by spot welding or tying steel wire with the help of mechanical connections.
Manufacturing Of Rebar:
Rebar is generally manufactured using high yield steel of grade. There are several forms in which you can find the rebars ::
Ø Round
Ø Ribbed
Ø Stretched, ribbed and twisted
Ø Square twisted
The different applications are:
Ø Square mesh: This mainly used in floor slabs
Ø Long mesh: Used in the construction of pavement and road.
Ø Rectangular mesh: This is also used in floor slabs
Ø Wrapping mesh: They typically support suspended slabs.
Rebars are available in different sizes, density and diameter as per the requirements of the construction.
Recycling And Reusing ::
In many countries when a building is being demolished, the workers are called upon to remove the rebar. The metals are extracted using welding equipments, bolt cutters and other tools. After this the metal is straightened, bundled together and the sold in the market. But it can be detrimental when used again in the construction work as after recycle the metal becomes less ductile. This results in the collapse of the building during earthquakes. Thus after recycling, rebar can only be used as scrap just like all other metals.
