Tips to measure the cutting length of a diamond stirrup

In this construction article, you will learn the steps required to measure the cutting length of a diamond stirrup alias Rhombus tie bar.

The purpose of column stirrups is to settle and verify the longitudinal (main) steel bars in columns to bulging against the vertical forces (compression force) specifically in the center of the column ahead of attaining the concrete.

In this regard, a solution is given to the following example :-

Assume, a diamond stirrup is applied in column that is 550 mm long and 450 mm wide (x-section). The clear cover in the column is 40 mm. The dia of stirrup bar is 10 mm.

The calculation is done based on the following data :-

Length of column = 550 mm
Width of column = 450 mm
Clear cover = 450 mm
Stirrup bar diameter = 10 mm
Length of the stirrup is unknown
Weight of the stirrup is unknown

Solution: The calculation method is divided in two steps. In first step, the Pythagoras theorem is used to measure the hypotenuse length of the right angle. In second step, the values produced are put in the formula.

Hypotenuse = √(Base Length)² + (perpendicular length)²

Base length
= {Length – 2(Clear Cover) – 2(Half of diameter of bar)}/2
= {550-2(40) – 2(5)}/2
= 460/2 = 230 mm

Perpendicular length
= {Width – 2(clear cover) – 2(half of diameter of bar)}/2
= {450 – 2(40) – 2(5)}/2
= 360/2 = 180 mm

The hypotenuses is measured by providing the value of base & perpendicular in the pythagoras theorem.
Hypotenuses = √(230)² + (180)²
= √52900 + 32400
= √85300 = 292 mm

Cutting length of diamond stirrup

Cutting length:
= (4 x H) + 2(10d) – 3(2d)

H denotes the length of the hypotenuse that is measured in the first step.

10d denotes the length of the hook and “d” belongs to the diameter of the bar.
2d = 90*bands
3d = 135*bands

By providing the specified data values and hypotenuse value in the formula, the length of the stirrup is obtained.

By providing the values

Cutting Length:
= (4 x 292) + (200) – (60) –(60)
= (1196) + (200) – (60) – (60)
= (1396) – (120)
= 1248 mm or 1.248 m

Weight of the stirrup:
The weight of the stirrup is measured with the following formula.
Weight
(D²/162.2) X Length
(10 x 10)/162.2 x 1.248
0.616522 x 1.276
0.77 kg or 770 gram

So, the length of the diamond stirrup in the column is 1.248 meters. Together with all two hooks, the weight of the stirrup will be 770 grams if 10 mm bar is utilized.