What is cranking in reinforcement bars?

Crank is a slight bending in bars at the lap so that maintains the clear cover even at the lap position. The rule that is generally practiced is that the slope of crank 1:10 & minimum length of crank 300 mm.

What is cranked beam?

What is a cranked beam? The simple answer is: a cranked steel beam in an angled beam with two kinks in it, making a 90-degree angle. The main function of a cranked beam is to support roof structures — so they need to be welded extra tight.

Why bars are cranked?

Cranked bars / Bent up bars are provided on top of the reinforcement to resist negative bending moment/Hogging at the supports of the slab. When bent up bars are provided, the strength and deformation capacity of slabs with bent up bars compared to slabs without bent up bars is sufficiently increased.

Why bars are bent in slab?

Bars Are Bend Near At Support To 1- To resist shear force. 2-To resist (NBM) adjacent at supports. 3- To increment the strength of RCC in the slab. 4- Bent Up bar can abate the amount of steel.

Why are bars bent at end?

We bend the bars in beams at the end, so that they can act as an hook and provide Anchorage to the beam at the ends. Usually at the end of the beams the bars are bend in the form of” L” shape or inverted L shape that is this bars are inserted into the columns.

What is the importance of crank bars in RCC beam construction?

The crank bars or bent up bar are very important in R.C.C beam or slabs construction because without countering the Hogging (Negative moment) the structure will fail or the strength of the structure will reduce.

Why is crank bar important for slabs?

Crank bar, also known as bent up bar is very important for slabs. It is also important for preparing a bar bending schedule. What Is Crank Bar? Different shape of cranks bar is provided in the slab and other structural members. Bars are bent near the supports normally at an angle of 45°.

What are the means bends on the crank bars?

2. Different Angles on the crank bar (Means bends) are provided in the slabs. we just provide Straight Bars at the end on the top of the slab, and in some cases, we provide angles on the slab crank bars, which is 45°. In some cases, the 30° bent is provided when shallow beams are present at the end of the slabs.

Why do we use bottom steel in RCC slab?

So bottom steel is required at the mid-span and top steel resists negative moments at the supports. A crank bar is provided to make RCC slab safe from compressive stresses. When these bars are provided, the strength and deformation capacity of slabs with bent up bars compared to slabs without bent up bars is sufficiently increased.