BBS - What is Bar Bending Schedule (BBS) | Excel sheet | Formulas | Things to Know | Advantages -lceted LCETED INSTITUTE FOR CIVIL ENGINEERS

## May 14, 2022

In This Article, We Explained About BBS - What Is Bar Bending Schedule (BBS), Things To Know Before Preparing a Bar Bending Schedule,  How To Prepare a Bar Bending Schedule on excel, and the Advantages of Using BBS

What is Bar Bending Schedule (BBS)?

Bar Bending Schedule is a comprehensive list of bent reinforcement bars given in any structural concrete element.

Bar Bending Schedule Contains size, shape, location, mark, type, length, number, and bending details

Bar bending is the process of cutting the reinforcement steel bar in the shape of a desired according to the structural drawing provided by the structural engineer for various structural elements such as slab, column, beam, and foundation.

A bar bending table allows site engineers to estimate the required dimensions of bars of different diameters used in construction. This allows the engineer to verify the reinforcement work done by the contractor.

Things to Know Before Preparing Bar Bending Schedule

1. What are the various diameters of the steel bars used in various structures?

6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 28mm, 32mm, 36mm, 40mm

2. What is the standard length of a steel bar?

40 feet or 12m long

3. Unit Weight of Steel Bar Formula | Steel weight and formula for unit weight of steel calculation

Weight of Steel Bar = D²/162 kg/m in Kg and Length ‘L’ in m

Weight of Steel Bar = D²/533 kg/feet in Kg and Length ‘L’ in foot

e. Diameter of Reinforcement Bars (in inches)

6. How many pieces are in a TMT bar bundle? TMT Weight per Bundle?

Note: The length of the TMT Steel rod will be 12 meters or 40 feet.

 TMT SIZE TMT RODS PER BUNDLE TMT WEIGHT PER BUNDLE 8mm (1 Bundle) 10 47 Kg 10mm (1 Bundle) 7 53 Kg 12mm (1 Bundle) 5 53.4 Kg 16mm (1 Bundle) 3 56.88 Kg 20mm (1 Bundle) 2 59.2 Kg 25mm (1 Bundle) 1 46.2 Kg 32mm (1 Bundle) 1 75.72 Kg

7. Cutting Length of Main Reinforcement Bar with Hook | How to find the total length of the bar having a hook at both ends?

8. How is bar bend length calculated?

9. Overlapping

The standard length of Rebar is 12m. Suppose the height of the column is 20 m. To purvey this requirement, two bars of length 12m and 8m are overlapped (joined) with overlap length.

Overlap Length for compression members (columns) 50d

The Overlap Length for tension members (beams) = 40d

[Where d is the Diameter of the bar]

10. Bend Deduction

The Bend length calculation is different for Cranked bars (bent up bars) and bends at corners. The bars are usually cranked in Slabs and bars are bent at corners in Stirrups or ties.

The formulae for bend deduction are

1. For 45° bend = 1 x d

2. For 90° bend = 2 x d

3. For 135° Bend = 3 x d

4. For 180° bend = 4 x d

11. Concrete Cover:

12. How do I format a BBS in Excel? | Format for Bar Bending Schedule in Microsoft Excel | BBS SHEET | BBS EXCEL SHEET | Bar bending schedule BBS excel sheet

How to prepare bar bending schedule?

Preparation of Bar Bending Schedule

Step 1: Identification of Members (Steel Bars)

Step 2: Count the Number of bars

Step 3: Calculate the length of the Reinforcement bars

Step 4: Calculate the unit weight of the Reinforcement Bar

Step 5: Calculate the Weight of a particular Shape of the Bar

Step 6: Calculate the Total Weight of bars needed

What is the data required for preparing BBS?

• Bar number/Bar Mark Reference

• Bar shape

• Diameter

• Spacing

• Length of bar

• Cutting Length

• Number of bars

General Guidelines To Be Followed In Preparing BBS

1. The bars should be grouped together for each structural unit, e.g. beam, column, etc.

2. In a building structure, the bars should be listed floor by floor.

3. For cutting and bending purposes schedules should be provided as separate A4 sheets and not as part of the detailed reinforcement drawings.

4. The form of bar and fabric schedule and the shapes of bar used should be in accordance with BS 8666.

5. It is preferable that bars should be listed in the schedule in numerical order.

6. It is essential that the bar mark reference on the label attached to a bundle of bars refers uniquely to a particular group or set of bars of defined length, size, shape and type used on the job.

7. This is imperative as a bar mark reference can then point to a class of bar characteristics. Also, this helps steel fixers and labourers keep track of the type and number of bars needed to complete a certain work.

BBS helps to estimate the total quantity of steel required for the construction of building or structure. It helps to quote for tender the cost incurred by steel.

Finding the cutting length and bending length in reinforcement detailing improves the quality of construction and minimize the wastage of steel, making an economic construction.

With the help of reinforcement drawings, cutting and bending can be done at the factory and transported to the site. This increases faster construction and reduces the total construction cost.

For site engineers, it becomes easy to verify the cutting length and bending length of the reinforcement before placing the concrete.

#### 1 comment:

1. Nice article, All BBS Formulas with example Download from here: Stirrups Cutting Length Formula

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