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# Bar Bending Schedule for RCC Beam

## BBS for RCC Beam:

Bar bending schedule (BBS) used for give the detail of information of reinforcement that how much cut length of steel, type of bend and bend length should be provided. Bar bending schedule is the abbreviation of BBS which describes the number of steels, length, size, type, mark and location this process gives detail about type, size, number, location and length of steel is called bar bending schedule. For preparing the bar bending schedule the details of reinforcement are shown in structural drawing of reinforcement.

### Bar Bending Schedule (BBS) used by

Bar bending schedule is used by different kind of peoples and authorities on construction site which is given below:

• Quantity surveyor
• Steel fixer
• Contractor
• Project manager
• Inspectors
• Clerks of construction

In construction site all estimation and costing operation is the responsibilities of quantity surveyor. The bar bending schedule gives the details to quantity surveyor for finding out the number of steel its type, size and shape. Contractor are using bar bending schedule (BBS) for ordering the steel bar for proceeding the construction. Steel fixer using bar bending schedule (BBS) for doing their work or installing the bar in column, beam or slab according to the bar bending schedule (BBS) that how much cut length or bending of bar will be needed and which size of steel should be use. The inspector and clerks of construction refers to the BBS to make are that the reinforcement work in the field is in proper with the design reinforcement as per drawing.

### Steps for Preparation of a BBS:

Most of details and information in bar bending schedule is present in structural drawing of steel which is shape, dia, length and spacing of bars. The steps for preparing the bar bending schedule are as follow:

• Number of bars
• Shape of bar
• Dia of bar
• Spacing between reinforcement
• Cut length of steel
• Bar mark reference
• Length of steel

For preparing a bar bending schedule we must take an example which is given below:

#### Example of RCC Beam Calculation:

Let a beam having 6 m length, 200 mm wide 400 mm depth. The bar at the top is provided having dia of 2 – 12 and 3 – 16 dia of bar at the bottom. The dia of stirrup is 8mm and spacing is 150 mm. clear cover in reinforcement is 25 mm.

Detail of RCC Beam

Cross Section of RCC Beam

Solution:

To preparing bar bending schedule in RCC beam the following factors should be find that is given below:

Length OF:

• Top bar
• Bottom bar
• Stirrup

Numbers OF:

• Steel
• Stirrup

Weight OF:

• Top bar
• Bottom bar
• Stirrup
##### Steps for BBS of RCC Beam:

Generally, there are mainly three steps to make the bar bending schedule for RCC bream

Step 1:

The equation of length of top bar:

Length of top bar = clear span + 2 (width of wall) + 2 (bend up bar) – 2(concrete cover)

& the equation for Bend up bar length:

Bend up Bar = 6d

Where d is the dia of bar

The dia of bar, “d” is 12mm as given in example of RCC Beam;

Bend up bar length = 6(12)

Bend up bar length = 72mm

Bend up bar length is 72 mm assumed as 72 mm

Putting the values in this formula

Length of top bar = 6000 + 2(200) +2(72) – 2(25)

Length of top bar = 6502 mm ≈ 6.50 m

Step 2:

Now the second step is to find bottom bar:

Length of bottom bar = clear span + 2 (width of wall) + 2 (bend up bar) – 2 (concrete cover).

The formula for Bend up bar length:

Bend up bar length = 6d

where d is the dia of bar

Ben up bar length = 6(16)

Ben up bar length is 100 mm

Putting the values in the equation of length of top

Length of bottom bar = 6000 + 2(200) +2(80) – 2(25)

Length of bottom bar = 6550 mm ≈ 6.55 m

Step 3:

Now finding the length of stirrup

There are four sides in rectangle stirrup the opposite sides are equal in rectangle so we find the two sides A and B.

Calculation of side A

Length of side A = (200 – 2(25)) x 2

Length of side A = 300 mm

Calculation of side B

Length of side B = (400 – 2(25)) x 2

Length of side B = 700 mm

Hook length as per IS 2502 – table II

Hook length for stirrup is 9d where d is dia of bar

Hook length = 9 x 8 = 72

Length of stirrup = side A + side B + 2 (hook length)

Length of stirrup = 300 + 700 + 2 x 72

Length of stirrup = 1144 mm ≈ 1.14 m

## BBS for RCC beam:

 S. NO Bar Mark Bar dia No of bars Length (m) unit weight(m/kg) weight of steel (Kg) 1 B1 12 2 6.5 0.888 11.54 2 B2 16 3 6.55 1.57 30.85 3 S 8 41 1.14 0.395 18.46 Total Weight of Reinforced Concrete Beam 60.85

Note:

• B1 = Top bar of beam
• B2 = Bottom bar of beam
• S = stirrup of beam
• To find the weight of steel multiply number of bars with length and unit weight of steel (weight of steel = No of bars x Length x unit weight of steel)