Bar bending schedule offers the **reinforcement calculation** for reinforced concrete beam. It supplies details of reinforcement cutting length, type of bends and bend length.

Here we will take one example for reinforcement quantity calculations for a concrete beam.

**Example of RCC Beam Reinforcement Calculation:**

Assume a beam of clear length of 4m, 300mm wide by 450mm depth. It consists of 2-12 diameter bars at top, and 2-16 diameter and 1 – 12 diameter bars at the bottom. Diameter of stirrup is 8mm spaced at 180mm center to center. Clear cover to reinforcement provided is 40mm.

Now we will calculate the length of **reinforcement** on the basis of shapes of reinforcement mandatory for reinforced concrete beam in above example.

We will start with bottom reinforcement, B1.

**Bar shape of B1 is as shown below:**

RCC Beam Bar Bending Shape

Length of B1 = clear distance between walls + 2 x width of walls – 2 x bar cover + 2 x bend length

Bend length = 6 x 16 = 96 consider as 100mm

Bend length is calculated as 6 x diameter of bar for **reinforcement conforming** to IS: 1786-1961

Length of B1 = 4000 + 2 x 230 – 2 x 40 + 2 x100 = 4580mm

**Length of bar B2 is calculated on the basis of the shape of this bar. This bar bends up closer to the support as shown below:**

RCC Beam Bar Bending Shape

Length of bar B2: A + B + C = 4000 + 2 x 230 – 2 x 40 + (1.414xH – H)

H = 450 – 2 x 40 – 2 x 12 – 2 x 12/2 = 334mm

B2 = 4000 + 2 x 230 – 2 x 40 + (1.414×334 – 334) = 4518.3 = 4520mm

Length of Bar T1 = 4000 + 2 x 230 -2 x 40 = 4380mm

**Length of Stirrups S1:**

RCC Beam Stirrups Length Calculation

Stirrups are spaced at 180mm center to center. Stirrups are provided between walls or support for a beam.

No. of stirrups required for given beam = No. of Stirrups

Length a = 450 – 2 x40 – 8 = 362mm

Length b = 300 – 2 x 40 – 8 = 212mm

Therefore length of 1 stirrup S1 = 2 x (212 + 362 + 90) = 1328 mm

Where 90mm is the minimum hook length as per IS 2502 – Table – II.

~~~~~~~~~~~~~~~~~~~~~

Published By

Arka Roy

**www.constructioncost.co**

~~~~~~~~~~~~~~~~~~~~~