# BBS of foundation Bar Bending Schedule Tutorial

We are going to learn how to crate a bar bending schedule bbs of a Foundation. We are going to use all the formulas we learned in How to create a bar bending schedule. I recommend you read the basic article first.

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.

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