The Bar Bending Schedule App is available for Android devices, making it easily accessible for most engineers.

BBS App Google Play Link: Click here to download

In this article we are going to learn how to use bbs app to make your bar bending schedules.

Main BBS App Interface

When you first open the BBS app you will see three different sections, few buttons on the top, a few buttons on the right and a large blank portion. The top button bar is known as Top Tool Bar we will use this when editing your drawing or your bbs, button bar on the right is known as Right Action Bar, we will use these to make bbs, and the large blank section is where you will draw your rebars, its known as the Drawing Canvas

Right Action Bar

There are four buttons on the right action bar lets see what they are and how to use them

Add Rebar

Add button is the first button you will use after you have drawn your rebar on the canvas, Add Rebar button does exactly what the name suggest it adds the bar to your bbs, when you draw anything on the canvas you will notice that Add rebar button starts to blink, because that’s what you need to do. After you draw your bar you need to add it to your bbs.

Generate BBS

Generate BBS is the second button you will press after you add your bar. This is how you create your bbs on the BBS maker app. When you click this button the app takes all your added bars and create a bbs out of it. So for this to work you need to add at least one bar first.

Remove Bar

As the name suggest if you want to remove a bar you will use this button, if there’s a mistake in one of your added bar you will select that bar using the next or previous buttons form the top tool bar and once the bar you want to remove is on the canvas you press the Remove bar button to remove it from the bbs.

Saved BBS

This is the simplest one of them all, if you have saved your bbs for the future, they will appear in the saved section, just press this button to go to the Saved bbs screen where you can browse all your saved bbs.

Top Tool Bar

There are seven buttons on the top tool bar lets learn what they are and how to use them.

Lock Canvas

First button on the far left is the Lock Canvas button, when you press this button you won’t be able to draw on the main canvas and all the other buttons in the top tool bar and right action bar will be disabled (except for unlock button). You will use this when you don’t want anyone to accidentally draw or press any buttons.

Unlock Canvas

Unlock button does what the name suggest it unlocks the drawing canvas and enables all the buttons on the right action bar and top tool bar.

Clear Canvas

Clear Canvas removes the currently drawn rebar from the drawing canvas, when you draw a bar on the canvas you will notice two buttons starts to blink, add button and clear canvas button. Its because there are the two things you can do once you draw a bar, either add that bar to the bbs or clear the canvas and restart drawing. You clear you canvas through the Clear Canvas button

Undo Drawing

Process of Drawing rebar on the BBS app is as follows, you touch the canvas and drag you finger across to draw a line, then you lift you finger and touch anywhere else on the canvas, another line is drawn to the point you touched from the end point of the previous line, if you accidentally drew a wrong line segment and want to undo it instead to clearing the canvas and draw the whole bar from the start, you use the undo drawing button to undo the last drawn line segment

Redo Drawing

If you accidentally undo a line segment instead of drawing it agin you can just press the redo button and the line segment will be redrawn automatically

Next Bar

When editing a bar or removing a bar you need to first select it, when you have multiple bars in you bbs, you toggle forward in your bbs through the next bar button, when you press the next bar button the bar next in your bbs will be selected and shown on your drawing canvas, this will happen until you reach the last bar on your canvas.

Previous Bar

If you want to go back in your bbs and select a previous bar you press the previous bar button. When you press the previous bar button previous bar will be selected and shown on the drawing canvas this will keep happening until you reach the first bar in your bbs

Dark/Light Mode

Last button not he main screen is the Dark/Light Mode button, this one needs no explanation, at night of in low light conditions you can toggle dark mode this will cause less strain on your eyes and in daylight or well light room you can use Light mode with this you will be able to see clearly in daylight conditions.

The Bar Bending Schedule App is available for Android devices, making it easily accessible for most engineers.

BBS App Google Play Link: Click here to download

As you can see from the drawing above there are two kinds of bars in this slab. One bar along the main x direction and another one along the y direction. It might seem that we have 4 bars but if you look carefully the black and red bars are actually the same bar but in the opposite direction.

So lets start with the Main X bars

Length of rebar

Slab has a width of 4 m 

There is cover of 25mm on each side = 25mm+25mm= 50mm = 0.05m

Effective Slab length = slab width – cover = 4m – 0.05m = 3.95m

Bar Length = Slab length + inclined length

D = Slab Height – cover = 150 – (25 +25) = 100mm

Inclined length = 0.42*D

                         = 0.42*100= 42mm

Total Length of Main X bar = Effective Slab length  + inclined length

                                           = 3.95 + 0.042= 3.992m

Bend Deduction

As we already have learned in the basic of bar bending schedule that for every 45 degree bend we apply a deduction equal to d( 1 times diameter)

Here we have two 45  degree bend so we must apply a deduction of d+d to the total length of the bar

Deduction = 12 +12=24mm = 0.024m

Effective Length =  Total Length – Deduction

                           = 3.992 – 0.024

                           = 3.968m

Number of bars

No of bars = Distance/spacing + 1

Distance = Slab length – cover = 3.95m

Spacing = 120mm

No of Bars = 3950/120 +1

                  = 33+1

                  = 34

Unit Weight

We know that Unit weight of any bar = d2/162

Here out diameter= 12mm

Unit weicht = 12*12/162 = 0.89 kg/m

Total Weight

Total weight = Length*number*Unit Weight

                    = 3.968 * 33* 0.89

                    = 116.54 Kg

Main x rebar

Main Y rebar 

Length of rebar

Slab has a width of 5 m 

There is cover of 25mm on each side = 25mm+25mm= 50mm = 0.05m

Effective Slab length = slab width – cover = 5m – 0.05m = 4.95m

Bar Length = Slab length + inclined length

D = Slab Height – cover = 150 – (25 +25) = 100mm

Inclined length = 0.42*D

                         = 0.42*100= 42mm

Total Length of Main X bar = Effective Slab length  + inclined length

                                           = 3.95 + 0.042= 4.992m

Bend Deduction

As we already have learned in the basic of bar bending schedule that for every 45 degree bend we apply a deduction equal to d( 1 times diameter)

Here we have two 45  degree bend so we must apply a deduction of d+d to the total length of the bar

Deduction = 8 +8=16mm = 0.016m

Effective Length =  Total Length – Deduction

                           = 4.992 – 0.016

                           = 4.976m

Number of bars

No of bars = Distance/spacing + 1

Distance = Slab length – cover = 4.95m

Spacing = 120mm

No of Bars = 4950/120 +1

                  = 41+1

                  = 42

Unit weight

Unit weight of any rebar = d2/162

                                       = 8*8/162

                                       = 0.395 Kg/m

Total Weight

Total weight =Length*number*Unit Weight

                    = 4.976 * 42* 0.395

                    = 82.55 Kg

So here is the full bbs of Slab

If you want a free software to make bar bending schedule I highly recommend you download the official BBS app

BBS App Android Google Play Link: Click here to download

iPhone AppStore Line: Click here to download

If you are a fresher civil engineer and want to know how to get a job read this article: How to get a  job as a fresher civil engineer.

Let’s first see what  bend deduction is and how to apply it.

When you bend rebar it stretches.

When you stretch a 100g loaf of bread, it still weighs 100g, stretching it will increase its length but not weight.

So instead of directly multiplying the Unit weight with the length, we must first decrease the length by the amount it was stretched.

A bar stretches “d units” for every 45-degree bend where d is the diameter of the rebar

This means

D for 45

2D for 90

3D for 135

And

4D for 180

So we count the number and angle of bends and subtract the length of the stretched bar with these values to get the actual length before multiplying it with the Unit Weight.

If you want a free software to make bar bending schedule I highly recommend you download the official BBS app

BBS App Android Google Play Link: Click here to download

iPhone AppStore Link: Click here to download

If you are a fresher civil engineer and want to know how to get a job read this article: How to get a  job as a fresher civil engineer.

When making a bar bending schedule, a deduction of 1 bar diameter is typically taken for 45-degree bends. This deduction is taken to account for the length of the bend and to ensure that the overall length of the rebar is maintained.

For example, if the diameter of the rebar is 12 mm, then the deduction for a 45-degree bend would be 12 mm (1 x 12 mm). This means that the length of the rebar needed for the bend would be 12 mm shorter than the length required for a straight section of the same rebar.

It is important to note that the deduction amount may vary depending on the specifications and requirements of the project. Therefore, it is recommended to consult with the project engineer or relevant authority for specific deduction values.

Why is Deduction Important in Bar Bending Schedule?

Deduction is an essential aspect of Bar Bending Schedule as it helps in the accurate calculation of the quantity of steel required for the construction project. The accurate calculation of the quantity of steel required is crucial as it can significantly impact the cost and timeline of the construction project. Incorrect calculations can lead to either the wastage of steel or a shortage of steel, both of which can have adverse effects on the overall construction project.

The deduction also ensures that the overlapping of the steel bars is done correctly, which is critical to the structural integrity of the construction project. The overlapping of the steel bars provides the necessary strength and stability to the structure, and any error in the calculation can lead to a weak and unstable structure.

As you can see from the drawing above there are two kinds of bars in this beam. One is long  U shaped Main bars, and the other one is a Stirrups that keep the Main bars together, in beam we have stirrups but in column we don’t call them stirrup we call them column ties.

So lets start with the Main bars

Length of rebar

Beam has a width of 2.5m  (Our rebars extend the entirety of this width)

Our bars extends to the columns on both sides which has a width of 250mm minus 25mm cover on both sides = (250mm – 25mm) + (250mm – 25mm) (We have 2 columns)

                       = 450mm = 0.45m

Now our rebars bends 90 degree and extends a distance equal to 25 times diameter

                     = 25*12 + 25*12 ( 12mm diameter and two bends one on each side)

                     =600mm

                     = 0.6m

Total Length of Main rebars = Beam Width + Part that’s extend to column + L bends extensions

                                             = 2.5 + 0.45  0.6

                                             = 3.55m

Deduction

As we already have learned in the basics of bar bending schedule that for every 45 degree bend we apply a deduction equal to d( 1 times diameter)

Here we have two 90 degree bend so we must apply a deduction of 2d + 2d to the total length of the bar

Deduction = 2*12 +2*12=48mm = 0.048m

Effective Length =  Total Length – Deduction

                           = 3.55 – 0.048

                           = 3.502m

Number of bars

In this case we can see that number of bars are 4

In other much complicated cases we use the formulae 

No of bars = Distance/spacing + 1

But we won’t do this here because we can simply count the number of bars here.

Unit Weight

We know that Unit weight of any bar = d²/162

Here out diameter= 12mm

Unit weicht = 12*12/162 = 0.89 kg/m

Total Weight

Total weight = Length*number*Unit Weight

                    = 3.502 * 4* 0.89

                    = 12.467 Kg

Beam Stirrups

Length if rebar

As we can see form the drawing, beam has a width of 0.25m

But there is a cover of 25mm on both sides 

Total Cover = 25mm+25mm=50mm= 0.05m

 Effective width= 0.25-0.05=0.2m

Similarly Effective length = 0.2m

Our stirrup has four sides and 2 hooks

Hooks have a length of 5 times diameter = 5*8 (8mm diameter of column ties)

                                                                  =40mm

2 Hooks  = 2*40mm = 80mm

               = 0.08m

Length of stirrup = Length of 4 sides + Length of 2 hooks

                             = 4*0.2 + 0.08

                             =0.88m

Deduction

As we know for every 45 degree bend we apply a deduction equal to d(diameter of bar)

Here we have hook of 135 degree = 3*45 degree

So we will apply deduction = 3*d

Because we have 2 hooks So total Deduction = 3d+3d=6d

                                                                          = 6*8 (8mm diameter of ties)

                                                                          = 48mm

                                                                          = 0.048m

Effective Length = Length – deduction

                           = 0.88 – 0.048

                          = 0.832m

Number of bars 

We know that the formulae to calculate the number of bar 

Number of bars = Distance/ spacing +1

Stirrups are placed on the entire length of the beam

So distance is equal to length of beam = 2.5m= 2500mm

Spacing is given in the drawing equal to 120mm centre to centre

No of bars = 2500/120 +1

                  = 21 + 1 = 22

Unit weight

Unit weight of any rebar = d²/162

                                       = 8*8/162

                                       = 0.395 Kg/m

Total Weight

Total weight =Length*number*Unit Weight

                    = 0.832 * 22* 0.395

                    = 7.23 Kg

So here is the full bbs of beam

In the next article we are going to learn how to make bar bending schedule of a slab

If you want a free software to make bar bending schedule I highly recommend you download the official BBS app

BBS App Android Google Play Link: Click here to download

iPhone AppStore Line: Click here to download

If you are a fresher civil engineer and want to know how to get a job read this article: How to get a  job as a fresher civil engineer.

As you can see from the drawing above there are two kinds of bars in this column. One is long L shaped main bars, and the other are ties that keep the main bars together, in beam we have stirrups but in column we don’t call them stirrup we call them column ties.

So lets start with the Main bars

Length of rebar

Column has a height of 2.4m

Footing has a height of 0.5m

Total height = height of column + height of footing = 2.4+0.5=2.9m

Now as we can see the Main column bars do not go all the way to the bottom of the footing

At the bottom there is a cover of 50mm on top of that we have main bottom bar of 10mm on top of that we have bottom distribution bar of 10mm and on top of that our main column bar sits

Main column bar is 50mm+10mm+10mm=70mm above the bottom of fitting

Height of column bar = 2.9m – 0.07m= 2.83m

There is also L bend in our main column bar of length 25* diameter of bar=25*10 (diameter = 10mm)

Total Length = Height of column + L bend = 2.83+ 0.25 = 3.08m

Deduction

As we already have learned in the basic of bar bending schedule that for every 45 degree bend we apply a deduction equal to d( 1 times diameter)

Here we have one 90 degree bend so we must apply a deduction of 2d to the total length of the bar

Deduction = 2*10=20mm = 0.02m

Effective Length =  Total Length – Deduction

                           = 3.08 – 0.02

                           = 3.06

Number of bars

In this case we can see that number of bars are 4

In other much complicated cases we use the formulae 

No of bars = Distance/spacing + 1

But we won’t do this here because we can simply count the number of bars here.

Unit Weight

We know that Unit weight of any bar = d²/162

Here out diameter= 10mm

Unit weicht = 10*10/162 = 0.617

Total Weight

Total weight. = Length*number*Unit Weight

                    = 3.06 * 4* 0.617

                    = 7.55 Kg

Column Ties

Length

As we can see form the image column has a width of 0.25m

But there is a cover of 25mm on both sides 

Total Cover = 25mm+25mm=50mm= 0.05m

 Effective width= 0.25-0.05=0.2m

Similarly Effective length = 0.2m

Our column has four sides and 2 hooks

Hooks have a length of 5 times diameter = 5*8 (8mm diameter of column ties)

                                                                  =40mm

2 Hooks  = 2*40mm = 80mm

               = 0.08m

Length of column = Length of 4 sides + Length of 2 hooks

                             = 4*0.2 + 0.08

                             =0.88m

Deduction

As we know for every 45 degree bend we apply a deduction equal to d(diameter of bar)

Here we have hook of 135 degree = 3*45 degree

So we will apply deduction = 3*d

Because we have 2 hooks So total Deduction = 3d+3d=6d

                                                                          = 6*8 (8mm diameter of ties)

                                                                          = 48mm

                                                                          = 0.048m

Effective Length = Length – deduction

                           = 0.88 – 0.048

                          = 0.832m

Number of bars 

We know that the formulae to calculate the number of bar 

Number of bars = Distance/ spacing +1

Ties are placed on the entire length of the bar

So distance is equal to hight of column main bar = 2.83m= 2830

Spacing is given in the drawing equal to 12mm centre to centre

No of bars = 283/12 +1

                  = 24 + 1 = 25

Unit weight

Unit weight of any rebar = d²/162

                                       = 8*8/162

                                       = 0.395 

Total Weight

Total weight =Length*number*Unit Weight

                    = 0.832 * 25* 0.395

                    = 8.216 Kg

So here is the full bbs of column

In the next article we are going to learn how to make bar bending schedule of a beam

If you want a free software to make bar bending schedule I highly recommend you download the official BBS app

BBS App Android Google Play Link: Click here to download

iPhone AppStore Line: Click here to download

If you are a fresher civil engineer and want to know how to get a job read this article: How to get a  job as a fresher civil engineer.

If you look at the image you can see that there are essentially four types of bars,Bottom Main Bar,Bottom Distribution Bar,Top Main Bar and Top Distribution Bar

Along with these four bars there is also bars of the column. Technically you have to create bbs for this column along with the foundation. But just for the sake of simplicity I am going to do that in a separate article BBS of a column.

Lets start with the Bottom Main Bar

Length

As we can see Length of the foundation = 1m

There is 50mm cover on both sides so total cover = 50mm+50mm= 0.1m

The bar  has a 10d bent on both sides = 10d+10d= 20d= 0.20m (because d is 10mm)

 Total Length of bottom main bar = Length of foundation – cover + Lbends

                                                     = 1 – 0.1 +0.20=1.1m

Deduction

We know that for every 45 degree bend we apply a deduction equal to d (Diameter of the bar)

Here we have 2 90 degree bends so total deduction = 2d+2d=4d=0.040m

Effective Length = Total Length – Deduction = 1.1-0.040 = 1.06m

Number of Bars

Number of bars = Distance/Spacing +1

Here Distance = Length of Foundation -2* cover (2* 50mm =100mm)

Spacing is 100mm

 Number of bars = (1000-100)/100+1=9+1=10

Unit weight of 12mm bar = D²/162 = 10*10/162= 0.617

Hence Weight of Bottom Bar is = Length * Number *Unit Weight

                                                  = 1.06*10*0.617 = 6.54 kg

2: Bottom Distribution Bar

Length

Again in this case Length = 1m – 0.1m( cover )= 0.9m

The bar  has a 10d bent on both sides = 10d+10d= 20d= 0.20m (d is 10mm)

 Total Length of bottom main bar = Length of foundation – cover + Lbends

                                                     = 1 – 0.1 +0.20=1.1m

Deduction

We know that for every 45 degree bend we apply a deduction equal to d

Here we have 2 90 degree bends so total deduction = 2d+2d=4d=0.040m

Effective Length = Total Length – Deduction = 1.1-0.04 = 1.06m

Number of Bars

Number of bars = Distance/Spacing +1

Here Distance = Distance -2* cover – 2*diameter of main bar.  ( Notice these bars are placed inside main bars)

Spacing is 100mm

 Number of bars = (1000-100-24)/100=9+1=10 ( 8.76 round off to 9)

Unit weight of or 10mm bar = D2/162 = 10*10/162= 0.617

Hence Weight of Bottom Bar is = Length * Number *Unit Weight

                                                  = 1.06*10*0.617 = 6.54 kg

Because the top bars are nearly identical to the bottom bars we can simply copy our calculations for the top bars

Hence 

Top Main Bar = 6.54Kg

Top Distribution Bar = 6.54Kg

When we combine all of the bars we get bbs of the entire foundation

In the next article we are going to learn how to make bar bending schedule of a column

If you want a free software to make bar bending schedule I highly recommend you download the official BBS app

BBS App Android Google Play Link: Click here to download

iPhone AppStore Line: Click here to download

If you are a fresher civil engineer and want to know how to get a job read this article: How to get a  job as a fresher civil engineer.

By the end of this article I will give you a free tool for preparing bar bending schedule

How to calculate the weight of a rebar

Imaging a pencil weighs 1kg( I know it is insane but stay with me). Then 10 pencil will weigh 10kg, 100 pencils will weigh 100kg. Similarly, we can find the weight of rebar, we first calculate wt of 1m of a bar and then we simply multiply that weight with the no of meters of a bar we have.

Then the question is, how do we find weight of 1m of any rebar. The answer is simpler than you might think, it is simply d*d/162 where d is the diameter of the bar

So 8mm bar will weigh 8*8/162=0.395Kg/m

12mm bar will weigh 12*12/162=0.89Kg/m

And so on.

We call this the weight of 1 Unit of bar or simply the Unit Weight of Bar.

So a 10m of 12mm rebar will weigh 10 * 0.89=8.9kg

Or simply Length*UnitWeight

Bent Reinforcements

Now we are rarely going to use a straight bar. Most of the time we will have to bend the bar as per the designs received. This doesn’t change a thing, just add the length of all the bent sections of the bar and multiply it with the Unit Weight of the bar

Calculation of Number of bars

And we are rarely going to use a single bar

Normally you will be given a drawing with length width height of the structure and spacing to be used for a bar, you will have to calculate the no of bars

Number of bars = (Length -2*cover)/spacing +1

Where

Length is the length/width of concrete structure

The cover is the concrete cover

Spacing is the space between individual bars

Why +1?

To answer this let see a simple case where length is 5m and spacing is 1m( forget about cover for now )

In this case, No of bars is 5m/1m=5

Now let us provide five bars

As you can see there is still space left for one more and this is exactly why we add 1 extra bar

But wait we are not done, we still have one last thing to discuss.

Deduction in BBS

Depending on who you ask, this will either be the best thing or this is going to be the greatest sin you’ve ever committed.

Let’s first see what this is and how to apply it( Only If you have to )

When you bend rebar it stretches.

When you stretch a 100g loaf of bread, it still weighs 100g, stretching it will increase its length but not weight.

So instead of directly multiplying the Unit weight with the length, we must first decrease the length by the amount it was stretched.

People who support this say that a bar stretches “d units” for every 45-degree bend where d is the diameter of the rebar

This means

D for 45

2D for 90

3D for 135

And

4D for 180

So we count the number and angle of bends and subtract the length of the stretched bar with these values to get the actual length before multiplying it with the Unit Weight.

In this case Total Length is 2+1+1 = 3m

We have 2 90-degree angles so deduction is = 2D+2D=4D 

=48mm ( D is 12mm )

So the actual length is TotalLength- deduction=3-0.012=2.988m

Weight is ActualLength*UW*No=2.988*0.89*6=15.95Kg

Q: So, What should you follow?

A: Whatever the convention is on your site. Don’t get fired for listening to a guy on the internet.

If you want software for Bar Bending we have an excellent app for you. BBS- rebar weight calculator 

Just draw the shape of the bar on the app and enter some basic details and that’s it. 

The app will prepare the bbs for you.

BBS App Android Google Play Link: Click here to download

iPhone AppStore Line: Click here to download

If you are a fresher civil engineer and want to know how to get a job I highly recommend you read this article: How to get a job as a fresher civil engineer