How to Calculate Cutting Length of Stirrups in Beam and Column
In this article, we will see that the Cutting Length of Stirrups is calculated as follows. We have also become a calculator for this cutting length. Click “Calculator for Cutting Length of Stirrups” on this article for its link.
- Cutting Length for Rectangular Stirrups
- Cutting Length for Square Stirrups
- Cutting Length for Circular Stirrups
- Cutting Length for Helical Stirrups
- Cutting Length for Triangle Stirrups
- Cutting Length for Diamond Stirrups
Important Point
Cutting Length Formula for Reinforcement
- Length of reinforcement inside the beam & Column + Hook Length for Stirrups – Bend inside the Stirrup Shape (Ring)
Length of Reinforcement Inside the Beam & Column.
- Steel (Rainfoecemnt) inside the beam and column which is based on Stirrup Shape. In which we take its periphery as the steel length.
- The calculation of this length is done by subtracting the cover from the first one.
Hook Length for Stirrups ( As per IS 2502:1963 )
k in 2 in the case of Mild Steel conforming, ( As per IS 2502:1963, P-6, Note-1 )
k in 3 in the case of Medium Tensile Steel conforming, ( As per IS 2502:1963, P-6, Note-1 )
k in 4 in the case of Cold-worked Steel conforming, ( As per IS 2502:1963, P-6, Note-1 )
Most IMP (As per IS 2502:1963, P-6, Table-II, Note )
H = Hook allowance is taken as 9d, 11d, 13d, and 17d for k values 2, 3, 4 and 6 respectively and rounded off to the nearest 5 mm, but not less than 75 mm.
B = Bend allowance is taken as 5d, 5.5d, 6d, and 7d for k values 2, 3, 4 and 6 respectively and rounded off to the nearest 5 mm, but not less than 75 mm. 45° Bend = 1d, 90° Bend = 2d, 135° Bend = 3d (d = Dia of Stirrups)
Hook Length As Per Is Code
Sr.No. | Shape | Hook Length As Per Is Code | Single Ling Diagram | Cutting Length Formula for Reinforcement (d = Steel Dia) |
1 | 2 (A + E) + 24d | 2 (A + E) + 24d | ||
2 | 2 (A + E) + 20d | 2 (A + E) + 20d | ||
3 | 2A + E + 28d | 2A + E + 28d | ||
4 | L + 2H | L+2H = L + 2 x (4d+ d+2kd) = L + ( 4d +4d +d) x2 = L + 18d |
||
5 | Where P is not greater than D/5 N = Number of complete and fractional turns D = Internal dia P = Pitch of helix d = Size of barN π (D + d) + 8d |
– | N π (D + d) + 8d | |
B | 4C + 24d | 4C + 24d | ||
C | 4C + 20d | 4C + 20d |
#1. Cutting Length for Rectangular Stirrups
As per the drawing of the above column. We see some data. Which is as follows.
Step 1. Collect Data as Per Drawing
- Clear Cover: 25 mm
- Column Size: 200 mm x 600 mm
- Dia of Stirrups: 8 mm
Step 2. Apply Cutting Length Formula
Cutting Length Formula for Rectangular Beam and Column ( as Per Is 2502:1963 Page – 6 )
Formula of Cutting Length for Beam and Column Stirrup = 2 (a+b) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
Step 3. Find Data According to Formula
Lenth of stirrups a side = 600 – 2 side of the cover = 600 – (2 x 25 mm) = 550 mm
Lenth of stirrups b side = 200 – 2 side of the cover = 200 – (2 x 25 mm) = 150 mm
Step 4. After Finding the Data, Put That Data in the Formula and Count on It
Cutting Length for Beam and Column Stirrup = 2 (a+b) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
= 2 x (a + b) + (24 x d ) – (3 x 2d) – (2 x 3d)
= 2 x (550+150) + (24 x 8 (d = 8 mm stirrups) ) -(3 x 2 x 8) – (2 x 3 x 2)
= 1400 + 192 – 48 – 48
Step 5. All the Calculated Answer Is Cutting Length for Rectangular Beam and Column Stirrup.
Cutting Length for Rectangular Beam and Column Stirrup= 1496 mm or 1.496 m3
Also, Read: How to Calculate Slab Steel Quantity from Drawing | BBS of Slab
#2. Cutting Length for Square Stirrups
As per the drawing of the above column. We see some data. Which is as follows.
Step 1. Collect Data as Per Drawing
- Clear Cover: 25 mm
- Column Size: 400 mm x 400 mm
- Dia of Stirrups: 8 mm
Step 2. Apply Cutting Length Formula
Cutting Length Formula for Square Beam and Column ( as Per Is 2502:1963 Page – 6 )
Formula of Cutting Length for Beam and Column Stirrup = 2 (a+b) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
Step 3. Find Data According to Formula
Lenth of stirrups x side = 400 – 2 side of the cover = 400 – (2 x 25 mm) = 350 mm
Lenth of stirrups y side = 400 – 2 side of the cover = 400 – (2 x 25 mm) = 350 mm
Step 4. After Finding the Data, Put That Data in the Formula and Count on It
Cutting Length for Beam and Column Stirrup = 2 (a+b) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
= 2 x (a + b) + (24 x d ) – (3 x 2d) – (2 x 3d)
= 2 x (350+350) + (24 x 8 (d = 8 mm stirrups) ) -(3 x 2 x 8) – (2 x 3 x 2)
= 1400 + 192 – 48 – 48
Step 5. All the Calculated Answer Is Cutting Length for Square Beam and Column Stirrup.
Cutting Length for Square Beam and Column Stirrup= 1496 mm or 1.496 m
Also, Read: How to Calculate Staircase | Concrete & Bar Bending Schedule (BBS) | Staircase Reinforcement Details
#3. Cutting Length for Circular Stirrups
As per the drawing of the above column. We see some data. Which is as follows.
Step 1. Collect Data as Per Drawing
- Clear Cover: 50 mm
- Column Diameter: 300 mm
- Dia of Stirrups: 8 mm
Step 2. Apply Cutting Length Formula
Cutting Length Formula for Circular Column ( as Per Is 2502:1963 Page – 6 )
Formula of Cutting Length for Circular Stirrup = Circumference of Ring + 2 numbers of hooks – 2 numbers of 135° bends
Step 3. Find Data According to Formula
Where,
Circumference of ring = 2丌r (where r – Radius),
We know (r) radius of circle = d/2 (half of the diameter)
Diameter of Ring (d) = Diameter of Column (D) – Clear Cover = 300 – 50 – 50 = 200 mm
Radius of Ring r = d/2 = 200/2 = 100 mm
Step 4. After Finding the Data, Put That Data in the Formula and Count on It
So,
Length of Circular ring formula = 2丌r + (2 x 10d) – (2 x 3d)
= (2 x 丌 x 100) + (2 x 10 x 8 ) – (2 x 3 x 8)
= 628 + 160 – 48
Step 5. All the Calculated Answer Is Cutting Length for Circular Stirrups.
Cutting Length for Circular Stirrups = 740 mm or 0.74 m
Also, Read: What Is Staircase | Staircase Design Calculation Example | Concrete Calculation of Staircase
#4. Cutting Length for Helical Stirrups
As per the drawing of the above column. We see some data. Which is as follows.
Step 1. Collect Data as Per Drawing
- Clear Cover: 75 mm
- Column Diameter: 600 mm
- Dia of Stirrups: 8 mm
- Spacing of Stirrups: 200 mm
- Column Length: 20 m
Step 2. Apply Cutting Length Formula
Cutting Length Formula for Helical / Spiral Column ( as Per Is 2502:1963 Page – 6 )
Formula of Cutting Length for Spiral Stirrup = Number of Turns x √ [(Circumference of Stirrup)^{2} +(Spacing of Stirrups)^{2} ]
Step 3. Find Data According to Formula
Number of Turns = Length of Column ÷ Spacing of Stirrups
= 20000 mm ÷ 200
= 100 Numbers Turn.
Circumference of the Stirrups = π × Dia of the Stirrup
Dia of the Stirrups = Dia of Column – ( 2 x Clear Cover )
= 600 – (2 x 75 )
Dia of the Stirrup = 450 mm
So,
Circumference of the Stirrup = π x 450 mm
= 1414.35 mm
Step 4. After Finding the Data, Put That Data in the Formula and Count on It
Let’s putt these values into the formula.
Cutting Length for Spiral Stirrup = Number of Truns x √ [(Circumference of Stirrup)^{2} +(Sapcing of Stirrups)^{2} ]
= 50 x √[ (1414.35 mm )^{2} + ( 200)^{2 }]
= 50 x √[ ( 20,00,385.93 + 40,000) ]
= 50 x √[ ( 20,40,385.93) ]
= 50 x 1428.42 mm
Step 5. All the Calculated Answer Is Cutting Length for Spiral Stirrup.
Cutting Length for Spiral Stirrup = 71,421.00 mm or 71.421 m
Also, Read: What Is Bar Bending Schedule | Preparation as Per Bs 4466 | Tolerances as Per Bs 4466
#5. Cutting Length for Triangle Stirrups
As per the drawing of the above column. We see some data. Which is as follows.
Step 1. Collect Data as Per Drawing
- Clear Cover: 25 mm
- Column Size: 400 mm x 300 mm
- Dia of Stirrups: 8 mm
Step 2. Apply Cutting Length Formula
Cutting Length Formula for Triangle Column ( as Per Is 2502:1963 Page – 6 )
Formula of Cutting Length for Triangle Stirrup = (2 x H) + a + 2 numbers of hooks – 4 numbers of 135° bends
Cutting Length of Triangle Stirrup = (2 x H) + a + (2 x 10d) – (4 x 3d)
Step 3. Find Data According to Formula
Where,
Lenth of stirrups a side = 300 – 2 side of the cover = 300 – (2 x 25 mm) = 250 mm
Lenth of stirrups b side = 400 – 2 side of the cover = 400 – (2 x 25 mm) = 350 mm
Lenth of stirrups H = √[(b^{2 })+(a/2)^{2}] = √(350^{2})+(250/2)^{2}) = 372 mm
Step 4. After Finding the Data, Put That Data in the Formula and Count on It
Cutting Length of Stirrup = (2 x H) + a + (2 x 10d) – (4 x 3d)
= (2 x 372) + (250) + (2 x 10 x 8) – (4 x 3 x 8)
= ( 744) + (250) + (160) – (96)
Step 5. All the Calculated Answer Is Cutting Length of Triangle Stirrup.
Cutting Length of Triangle Stirrup = 1,058 mm or 1.06 m
Also, Read: What Is Well Foundation | Component of Well Foundation
#6. Cutting Length for Diamond Stirrups
As per the drawing of the above column. We see some data. Which is as follows.
Step 1. Collect Data as Per Drawing
- Clear Cover: 25 mm
- Column Size: 400 mm x 300 mm
- Dia of Stirrups: 8 mm
Step 2. Apply Cutting Length Formula
Cutting length formula for Diamond Column ( As per IS 2502:1963 page – 6 )
Formula of Cutting Length for Diamond Stirrup = (4 x H) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
Step 3. Find Data According to Formula
Lenth of stirrups H = √[(b/2)^{2 }+ (a/2)^{2}]
Lenth of stirrups a side = 300 – 2 side of the cover = 300 – (2 x 25 mm) = 250 mm
Lenth of stirrups b side = 400 – 2 side of the cover = 400 – (2 x 25 mm) = 350 mm
Therefore,
H = √[(b^{2 })+(a/2)^{2}] = √((350/2)^{2}+(250/2)^{2}) = 215 mm
Step 4. After Finding the Data, Put That Data in the Formula and Count on It
Cutting Length of Diamond Stirrup = (4 x H) + (24d) – (3 x 2d) – (2 x 3d)
= (4 × 215) + (24 x 8) – (3 x 2 x 8)-(2 x 3 x 8)
= (860) + (192) – (48) – (48)
Step 5. All the Calculated Answer Is Cutting Length of Diamond Stirrup.
Cutting Length of Diamond Stirrup = 956 mm or 0.96 m
Also, Read: What Are Columns | Different Types of RCC Columns | Round Column Vs Square Column | Pillars Vs Columns
Cutting Length Formula for Reinforcement
- Formula of Cutting Length for Rectangular Beam and Column Stirrup = 2 (a+b) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
- Formula of Cutting Length for Square Beam and Column Stirrup = 2 (a+b) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
- Formula of Cutting Length for Circular Stirrup = Circumference of Ring + 2 numbers of hooks – 2 numbers of 135° bends
- Formula of Cutting Length for Spiral Stirrup = Number of Turns x √ [(Circumference of Stirrup)^{2} +(Spacing of Stirrups)^{2} ]
- Formula of Cutting Length for Triangle Stirrup = (2 x H) + a + 2 numbers of hooks – 4 numbers of 135° bends
- Formula of Cutting Length for Diamond Stirrup = (4 x H) + hooks (24 d) – 3 numbers of 90° bends – 2 numbers of 135° bends
Hook Length for Stirrups
- For example, we have a rectangular column. But, the hook length shouldn’t be less than 75mm.
- So, the hook length of our example stirrup is 75mm.
- But if you cut this length of a bar for making the stirrup, it’ll be bigger than the required size.
Stirrups In Columns
- A stirrup refers to a closed loop of the reinforcement bar. Its main purpose is to hold the reinforcement bars together in an RCC structure.
- When used in a column, they provide lateral support to the main reinforcement bars to prevent buckling.
- They also prevent columns and beams from buckling.
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