Calculating Cutting Length of Rectangular Stirrup in Beams

 

How to Calculate Cutting Length of Rectangular Stirrup in Beams

 

 

How to Calculate Cutting Length of Rectangular Stirrup in Beams

The cutting length of a rectangular stirrup in a beam is calculated using the following formula:

Cutting length = Perimeter of stirrup + Hook length – Bend length

Calculating the cutting length of rectangular stirrups in beams requires a few key steps:

1.  Determine the size of the rectangular stirrup needed for the beam, typically this will be specified in the beam design or engineering plans. 

2.  Calculate the total length of the stirrup required based on the spacing between each stirrup, measured along the beam's length. 

3.  Subtract the length of the hooks on each end of the stirrup from the total length calculated in step 2. 

4.  Round this final value up to the nearest centimeter to get the cutting length of the stirrup.

Example Problem:

Beam width = 250mm, 

total depth = 4.0mm

 As per design, the spacing of stirrup is 150mm C/C. Diameter of stirrup = 8mm

Solution: 

Width of Stirrup = (2*8) + 250 + 10 = 276mm 

Length of Stirrup = Depth - 2 Cover - Dia of Stirrup Length of Stirrup = 4.0 - 2 25 - 8

 = 3.2mm Spacing 

= 150 mm C/C

Total no of stirrups required: 

= Length of beam/ spacing of stirrups 

= (6000 / 150) 

= 40 nos.

Total length of stirrup required 

= No of stirrups length of stirrup 

= 40 (3.2) = 15680 mm

Length of bent-up bar at one end = 20D 

= 20*8 = 160mm 

Length of bent-up bar at another end = 30D 

= 30*8 = 240mm 

Total cutting length of rectangular stirrup

 = Total length of stirrup - Length of bent-up bars (160+240) = 15380mm

 

Here are five more examples to illustrate the calculation:

1. Beam width = 200mm, total depth = 400mm, stirrup spacing = 100mm C/C, stirrup diameter = 6mm.

 2. Beam width = 300mm, total depth = 500mm, stirrup spacing = 200mm C/C, stirrup diameter = 10mm. 

3. Beam width = 400mm, total depth = 600mm, stirrup spacing = 150mm C/C, stirrup diameter = 8mm. 

4. Beam width = 500mm, total depth = 800mm, stirrup spacing = 250 mm C/C, stirrup diameter = 12mm. 

5. Beam width = 600mm, total depth = 1000mm, stirrup spacing = 300mm C/C, stirrup diameter = 16mm.