How to Calculate Cutting Length of Circular Ties (Links) in Columns
In concrete columns, circular ties are also called as links are used to hold the main steel bars in place.
Calculating the cutting length of these ties is important for accurate material estimation and structural integrity.
This following article will show you how to do it step by step with an example.
From on the imageÂ
Column diameter (D) =Â 600 mm – Outer diameter of the column.
Concrete cover =Â 40 mm (each side) – Clear cover to reinforcement
Diameter of link (d) =Â 10 mm – Size of the tie bar
Hook length =Â 9d
135° bend loss = 3d
Standard Bend Loss For Reinforcement
For 45° bend = 1 x d
For 90° bend = 2 x d
For 135° Bend = 3 x d
For 180° bend = 4 x d
Formula For Cutting LengthÂ
Cutting Length = Circumference of link + Hook Length – Bend Loss
Calculate Diameter of the Link (D)
Diameter of link = Column diameter – concrete cover in both sideÂ
So, Dia of Link (D) = 600 – 40 -40 = 520 mm
Calculate Circumference of the Link
Circumference of the Link = π x D (π = 3.14)
So, 3.14 x 520 = 1632.8mm
Calculate the Hook LengthÂ
Hook length = 9d (d= 10mm)
so, 9 x 10 = 90Â mmÂ
Total 2 hooks per tie. so, 90 x 2 = 180 mm
Calculate the Bend Loss
Circular ties typically have two 135° bends, each with a length of 3d.
Bend Loss = 3d = 3 x 10 =30 mm
Total 2 bends = 2 *30= 60 mm
So Cutting Length
Cutting Length = Circumference of link + Hook Length – Bend Loss
Cutting Length for Circular Link or Ties = 1632.80 + 180- 60 = 1752.8mm or 1.752 m
What about ties overlap length