Calculation By Volume Method
Required Data:
- Volume of the wall.
- Volume of a standard concrete block.
- Volume of openings in the wall.
Step 1:
Determine The Width, Height, And Thickness Of The Wall:
Let, the width of the wall = 10 feet.
The height of the wall = 10 feet.
The thickness of the wall = 8″ = 0.67 feet. [ Thickness of the wall will be same as the thickness of one concrete block]
Step 2:
Calculate The Volume Of The Wall:
We know, Volume = Width x Height x Thickness
∴ Volume of the wall = 10 x 10 x 0.67 = 67 cubic feet.
Step 3:
Calculate The Volume Of Openings:
If the wall has any openings such as door, windows, etc, calculate the volume of openings
Let the wall has a window of 3′ x 3′ x 0.67′ [ Thickness of the window will be the same as the thickness of the wall]
∴ Volume of the window = 3 x 3 x 0.67 =6 cu. ft
Step 4:
Subtract The Volume Of Openings From Volume Of Walls:
∴ Final volume of wall = 67 – 6 = 61 cu.ft.
Step 5:
Calculate The Volume Of A Concrete Block With Mortar Allowance:
Let the block is 16″ x 8″ x 8″ and mortar allowance is 1″
∴ The volume of one block with mortar = (16+1) x (8+1) x 8 = 1224 inch3 [The mortal will be given on the upper side and one side of every concrete block]
= 1224/12x12x12 = 0.70 cu.ft
Step 6:
Divide The Total Volume Of The Wall By Volume Of One Block:
∴ Number of blocks = Volume of wall/Volume of a block = 61/0.70 = 86
Consider 5% wastage of concrete blocks.
So the total numbers of blocks required = 86 + (86 x 5/100) = 86 + 4 = 90.
Note:
If the wall does not have any opening skip step 4, and just divide the surface area of the wall by the surface area of one block.
