How To Find Out The Cutting Length Of Main Bars & Circular Rings of Pile | Spiral Ring Cutting Length | Pile BBS Formula | Pile Cage Reinforcement | Rebar Weight of Pile:

In this post, we are going to see Cutting Length of Pile Main Bars | Cutting Length of Pile Circular Rings | Spiral Ring Cutting Length | Pile BBS Formula | Pile Cage Reinforcement | Rebar Weight of Pile | Bar Bending Schedule.

The main reinforcement in RCC structure like column and beam will behold in this closed loop of reinforcements. The spiral helical ring used in the column provides lateral support to the main bar against the buckling, which is applied to the beam and column at right intervals.

Also, they protect the RCC structure from collapsing during a seismic activity like an earthquake. It is used to resist lateral shear stress and diagonal tension stress in RCC structure and provide stability to the reinforcement of Steel bar. let us discuss how to calculate the cutting length of spiral stirrups.

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What is Bar Bending Schedule?

Bar Bending Schedule, commonly referred to as “BBS” is a comprehensive list that describes the location, mark, type, size, length and number, and bending details of each bar or fabric in a Reinforcement Drawing of a Structure.

This process of listing the location, type and size, number of and all other details is called “Scheduling”. In context of Reinforcement bars, it is called bar scheduling. In short, Bar Bending Schedule is a way of organizing rebars for each structural unit, giving detailed reinforcement requirements.

OTHER POSTS:

1. How to Make Bar Bending Schedule for Pile Foundation

2. How to Calculate Cutting Length of Rectangular Stirrups

3. Bar Bending Schedule of Slab | How to Calculate Reinforcement in Slab

After reading this article you will understand better how to work out the cutting length of the circular rings.

We used following dimensions to make the calculation:

Development Length (L) = 450 mm
Pile cap size = 1200 x 1200 x 500 mm
Circular Pile Of Dia = 600 mm
Main bars = 8 nos. 16 mm dia
Rings 10 mm dia @200 mm c/c
Hook Length = 10D
Cover for pile cap = 75 mm
Piles = 75 m

Rebar weight of the Pile:
Main bars:

Nos = 8; Dia = 16 mm; ribbed bars (unit weight – 1.58 kg/m)

We used the following formula to find out the cutting lenght:

{(Pile Depth + Pile Cap Depth) – (Pile Cover + Pile Cap Cover) + Development Length}

By putting all the values, we get the following :
= 9600 + 500 – (75 + 75) + 450 = 10400 mm = 10.4 m

The weight is calculated with the following formula :

Weight = N x CL x U
Here, N = Number of bars
CL = Cutting Length
U = Unit Weight

By putting the values, we get = 8 x 10.4 x 1.58 = 131.46 KG

Circular Stirrups or Rings:

Hook Length – 10 D = 10 x 10 = 100 mm
Ring Diameter = 600 – (75 + 75) = 450 mm { here dia of rings is taken as 600 mm & cover for pile is taken as 75 mm}

Ring Periphery = π.D = 3.14 x 450 = 1413 mm

Cutting Length Of Ring = Ring Periphery + 2 x Hook Length = 1413 +2 x 100 = 1413 + 200 = 1613 mm = 1.613 m

No. of Rings = [(Pile Length – Cover)/Spacing]+1 = [(9600 – 75)/200]+1

No. of Rings = 48.63 = Say 49 Nos

Weight = N x CL x U
Here, N = Number of bars
CL = Cutting Length
U = Unit Weight

Weight of Rings = N x CL x U = 49 x 1.613 x 0.62 = 49 Kg

Total Weight of Steel = Weight of Main Bars + Weight of Rings = 131.46 + 49 = 180.46 Kg

For More Detail Please see the above video

Advantages of Bar Bending Schedule:

Bar bending schedule provides details of reinforcement cutting and bending length. Advantages of bar bending schedule is when used along with reinforcement detailed drawing improves the quality of construction, cost and time saving for concrete construction works.

Advantages of bar bending schedule in concrete construction are:

1. When Bar bending schedule is available, cutting and bending of reinforcement can be done at factory and transported to site. This increases faster execution at site and reduces construction time and cost due to less requirement of workers for bar bending. Bar bending also avoids the wastage of steel reinforcement (5 to 10%) and thus saves project cost.

2. Using bar bending schedule for when used for Fe500, it saves 10% more steel reinforcement compared to fe415.

3. It improves the quality control at site as reinforcement is provided as per bar bending schedule which is prepared using the provisions of respective detailing standard codes.

4. It provides the better estimation of reinforcement steel requirement for each and every structural member which can be used to compute overall reinforcement requirement for entire project.

5. It provides better stock management for reinforcement. Steel requirement for next phase of construction can be estimated with accuracy and procurement can be done. This prevents stocking of extra steel reinforcement at site for longer time, preventing corrosion of reinforcement in case of coastal areas. It also prevents shortage of reinforcement for ongoing work by accurate estimation and thus concrete construction works can proceed smoothly.

6. Bar bending schedule is very much useful during auditing of reinforcement and provides checks on theft and pilferage.

7. Bar bending schedule can be used for reinforcement cutting, bending and making skeleton of structural member before it can be placed at the required position. Other activities such as excavation, PCC etc can proceed parallel with this activity. So, overall project activity management becomes easy and reduces time of construction. It becomes helpful in preventing any damages due to construction time overrun.

8. It provides benchmarks for quantity and quality requirements for reinforcement and concrete works.

9. Bar bending schedule provides the steel quantity requirement much accurately and thus provides an option to optimize the design in case of cost overrun.

10. It becomes easy for site engineers to verify and approve the bar bending and cutting length during inspection before placement of concrete with the use of bar bending schedule and helps in better quality control.

11. It enables easy and fast preparation of bills of construction works for clients and contractors.

12. The quantity of reinforcement to be used is calculated using engineering formulas and standard codes, so there is no option for approximate estimation of steel reinforcement.

13. With the use of bar bending schedule, mechanization of cutting and bending of reinforcement can be done, again reducing the cost and time of project and dependency on skilled labor requirement. It also improves the reliability on accuracy of bar cutting and bending.

14. When mechanized bar cutting and bending is used, the cost of reinforced concrete work per unit reduces and helps in cost optimization of construction project.

Conclusion:

Full article on Cutting Length of Pile Main Bars | Cutting Length of Pile Circular Rings | Spiral Ring Cutting Length | Pile BBS Formula | Pile Cage Reinforcement | Rebar Weight of Pile | Bar Bending Schedule. Thank you for the full reading of this article in “The Civil Engineering” platform in English. If you find this post helpful, then help others by sharing it on social media. For More detail please see the above video tutorial further you have any question regarding article please tell me in comments.