How to work out the cutting length of different types of square, rectangular and circular stirrups
This construction video provides some useful guidelines to compute the cutting length of different types of square, rectangular and circular stirrups in three steps. You will also learn what are the required clear cover, bend deduction as well as hook length for stirrups.
Given below, the details of actual increase in steel if it bends :-
Bend Elongation in steel
450 Bend – 1d elongation
900 Bend – 2d elongation
1350 Bend – 3d elongation
Elongation means the mechanical property of metal. It is the degree to which a material is likely to be delivered, expanded, or compressed before rupture. It refers to a point between tensile strength and yield strength and is demonstrated as a percentage of the original length.
Given below, the desired hook length in stirrups :-
Usually, the length fluctuates among 9d to 12; here d denotes diameter in mm.
Given below, the desired clear cover in column :-
Column – 25 mm to 40 mm
25 mm is taken when the diameter of prime reinforcement is equivalent to 12 mm.
40 mm is taken when the diameter of prime reinforcement is greater than 12 mm
The clear cover stands for the spacing among the exterior surface of steel and concrete.
While going to determine the cutting length of stirrups, always make calculation in center to center distance of stirrup
Cutting length of rectangular stirrups can be determined with the following formula :-
2 (A+B) + (2 x 12D) – (2 x 3D + 3 x 2D)
Here, A+B denotes center to center (c/c) dimension
2 x 12D denotes two hooks with 12D as length
2 x 3D + 3 x 2D denotes elongation of steel
2 x 3D means two stirrups with bend elongation in 1350
3 x 2D means 3 bends with bend elongation in 900
After putting all the values, we get 1104 mm
To get more details, go through the following video tutorial.
Video Source: fieldwork expert