General guidelines to be followed in preparing BBS:
• The bars should be grouped together for each structural unit, e.g., beam, etc.
• In a building structure, the bars should be listed floor by floor
• For cutting and bending purposes, schedules should be provided as separate A4 sheets and not as part of the detailed reinforcement drawings.
• The form of bar and fabric schedule and the shapes of the bar used should be in accordance with BS 8666.
• It is preferable that bars should be listed in the schedule in numerical order.
• It is essential that the bar mark reference on the label attached to a bundle of bars refers uniquely to a particular group or set of bars of defined length, size, shape, and type used on the job.
• This is imperative as a bar mark reference can then point to a class of bar characteristics. Also, this helps steel fixers and laborers keep track of the type and number of bars needed to complete a certain work.
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Bar Bending Schedule Required Ment Data
Estimation of steel quantity is an essential skill of any civil engineer. Every civil engineer must know the method of calculation of steel quantity from drawing.
Data requires for estimation of steel quantity:
1) Plan, Elevation & Section
2) Structural Detail (Slab & Beam)
3) All dimensions must be clear and co-related.
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How to prepare a Slab BBS?
We calculated her two parts of caution of BBS as below
1. Slab Beam.
2. Slab.
Slab Beam Bar Bending Schedule
Slab Beam Location
Here many beam shows. So we calculate TB1 Beam.
TB1 Beam.
Numbers of bars for Stirrups
Suppose the spacing of stirrups is 200 c/c and the length along which they are placed is 14100 mm, we can find the number of bars by the formula below
[ (14.100-200) / 200)] + 1 = 70.5 Nos
Total Num of Stirrups = 71 Nos
Stirrups Cutting Length
Cutting length beam stirrup
90 degree hook:
Length of stirrup = 2 (A + B) + 20 x dia
135 degree hook:
Length of stirrup = 2 (A + B) + 24 x dia
Length of stirrup = 2 ( (Lenght -2 Cover) + (Breadth-2 Cover) + 24 x Dia
Dia of Stirrups.
Length of stirrup = 2 (0.150 + 0.550) + 24 x 8
Length of stirrup = 1.592 m
Total Weight of Stirrups
Total Weight Stirrups = (No of ring x Cutting Length ) x (Weight dia of bars)
Total Weight Stirrups = ( 71 x 1.592) x (0.395) = 44.648 kg
We must remember than steel is ductile in nature and is subject to elongation. Hence, the length of a bar is increased when bends or hooks are introduced. Hence, certain deductions are needed to offset this increase in length.
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Cutting Length Bar:
Cutting Length = True Length of a bar – Deductions
For 45 degree
Cutting length = Total length – 1 x Dia of bar x No. of bends
Cutting length = (Total Length) +( 2 x L length) + (Lap Length (45 x d) ) – (2 x Bend) – (Cover)
Bottom Bar
2 nos bar 16 mm dia
Cutting length = (11.400+2.400+0.200) + ( 2x 0.550) + ( 45 x 16) – ( 2 x 0.016 ) -(2 x 0.025)
Cutting length = (14.100) + (1.100) + (0.720) – (0.032) – (0.050)
Cutting length = 15.838 m
Total weight of bottom bar = No of Bars x Cutting length x Weight of bars
Total weight of bottom bar = 2 x 15.838 x 1.580 = 50.048 kg
Top Bar
2 nos bar 20 mm dia
Cutting length = (11.400+2.400+0.200) + ( 2x 0.550) + ( 45 x 20) – ( 2 x 0.020 ) -(2 x 0.025)
Cutting length = (14.100) + (1.100) + (0.900) – (0.040) – (0.050)
Cutting length = 16.010 m
Total weight of top bar = No of Bars x Cutting length x Weight of bars
Total weight of top bar = 2 x 16.010 x 2.469 = 79.057 kg
Total Weight of Beam = Total Weight Stirrups + Total weight of bottom bar + Total weight of top bar
Total Weight of Beam = 44.648 kg + 50.048 kg + 79.057 kg = 173.753 kg
Slab Bar Bending Schedule Excel Sheet
Cutting Lenght Slab Bar
Cutting Langth of Bar = (Total length) + ( Bentup Bar Langht(0.42 x d)) +Lap
Area ( -1 to 3)/(-A to +B)
For X Direction
8 mm Dia 200 mm c/c
No of Bars = (7 /0.2) + 1 = 36.0 Nos. = 36 Nos
Cutting Bar = (0.100+2.400+4.300+1.000+2.800+1.000+0.100) +( 0.42 * (0.125-0.025-0.025)) + 0
Cutting Bar = (11.700) + (0.032) = 11.732 m
Total weight of X direction slab bar = No of Bars x Cutting length x Weight of bars
Total weight of X direction slab bar = 36 x 11.732 x 0.395 = 166.829 kg
For Y Direction
8 mm Dia 200 mm c/c
No of Bars = (11.700/0.200) + 1 = 59.5 Nos. = 60 Nos
Cutting Bar = (0.100+1.800+3.200+1.800+0.100) +( 0.42 * (0.125-0.025-0.025)) + 0
Cutting Bar = (7.000) + (0.0315) = 7.032 m
Total weight of Y direction slab bar = No of Bars x Cutting length x Weight of bars
Total weight of Y direction slab bar = 60 x 7.032 x 0.395 = 166.658 kg
Extra Bars
10 mm Dia 200 mm c/c
No of Bars = (11.700/0.200) + 1 = 59.5 Nos. = 60 Nos
TB2 area A/( – 1 to +3) = (0.500 + 0.200 + 0.900 ) = 1.600 m
Total weight of TB1 = No of Bars x Cutting length x Weight of Dia bar
Total weight of TB1 = 60 x 1.600 x 0.616 = 59.136 kg
No of Bars = (7 /0.2) + 1 = 36.0 Nos. = 36 Nos
TB3 area 4 (-A to +B) = (0.700 + 0.200 + 1.250 ) = 2.150 m
Total weight of TB3 = 36 x 2.150 x 0.616 = 47.678 kg
No of Bars = (7 /0.2) + 1 = 36.0 Nos. = 36 Nos
TB5 area 1/2 (-A to +B) = (1.250 + 0.200 + 1.400 ) = 2.850 m
Total weight of TB5 = 36 x 2.850 x 0.616 = 63.202 kg
Total weight of Slab = Total weight of X direction slab bar + Total weight of Y direction slab bar + Total weight of TB1 + Total weight of TB3 + Total weight of TB5
Total weight of Slab = 166.829 kg + 166.658 kg + 59.136 kg + 47.678 kg + 63.202 kg = 503.03 kg
How to Calculate Slab Steel Quantity from Drawing Excel Sheet
How to Calculate Slab Steel Quantity from Drawing Excel Sheet Click Here
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