How to calculate bar bending schedule for beam?

Bar Bending Schedule for Beam:

Consider the beam has a clear span of 6m consisting of two bottom layers (2 no’s of 20 mm dia. and 2 no’s 18 mm dia.) and a top layer ( 2 no’s 16 mm dia.).

Stirrup is provided in 3 zones where 1 & 3 have 8mm dia. www.hgftjz.blogspot.hu - 692140 RUB BAM MELSTROY jjbbq mm c/c and 2 has 8mm dia. @190mm c/c.

Given:

• Clear span = 6000mm
• Development Length Ld = 50d
• Clear cover = 30mm
• Bottom reinf. = 2 no’s 20 dia. and 2 no’s 28 dia.
• Top reinf. = 2 no’s 16 dia.
• Stirrup = zone 1,3 (8 dia. @ 140 mm c/c) and zone 2 (8 dia. @ 190 mm c/c)

Step 1: Calculation cutting length of top bar

Cutting length of top bar = clear span + development length – bend

Cutting length = L + (2 x Ld) – (2 x 2d)

= 6000 + (2 x 50 x 16) – (2 x 16)

=7568 mm

Step 2: Calculation cutting length of bottom bar

For first layer (20 dia.)

Cutting length = L + (2 x Ld) – (2 x 2d)

= 6000 + (2 x 50 x 20) – (2 x 20)

= 6920 mm

For first layer (18 dia.)

Cutting length = L + (2 x Ld) – (2 x 2d)

= 6000 + (2 x 50 x 18) – (2 x 18)

= 7764 mm

Step 3: Calculation number of stirrup

There are 3 zones first we need to calculate the length of each zone = L/3 = 6000/3 = 2000 mm

Number of stirrup for zone 1st and 3rd = (clear span / spacing ) + 1

= (2000/140) + 1 = 15.28 or 16 no’s

No. of stirrup for zone 2nd = (2000/190) – 1 = 9.52 or 10 no’s

Step 4: Cutting length of stirrup

Cross section of stirrup is 300x500mm

Effective depth (d) = 500 – (2 x 30) – (2 x 4)

= 432 mm

Cross section of stirrup is 300x500mm

Effective width (b) = 300 – (2 x 30) – (2 x 4)

= 232 mm

Cutting length = 2 (d + b) + hook – bend

= 2 x (432 + 232) + (9 x 8 x 2) – (2 x 8 x 3)

= 1424 mm = 1.42 m

Step 5: Calculate the weight of stirrup:

Total no. of stirrup = 16 + 16 + 10 = 42 no’s

Total length of stirrup = 1.42 x 42 = 59.64 m

Total weight of stirrup = 8 x 8 x 59.64/162 = 23.56 or 24 kg

Step 6: BBS of Beam: