Hey Guys, welcome to we civil engineers.
In this video, I'm going to teach you "How
to calculate the quantity of Bricks, cement,
and sand in a 4.5-inch thick brick wall.
So,let's get started.
Let's assume a wall of 10 foot long and 6-foot
height.
and the brick size as 9-inch x 4.5-inch x
3- inch.
Let's say the thickness of the mortar is 0.3-
inch.
As you can see in the picture, This brick
is surrounded by the mortar all the sides.
So, if you add the thickness of mortar the
brick size then you will get the exact number
of bricks.
Therefore, Brick size with mortar equal to
9inch +0.39 inch x 4.5 inch+0.39inch x 3inch+0.39inch,
which is equal to 9.39 inchx4.89inchx3.39inch.
As we already knew the thickness of the wall
is 4.5-inch.
To calculate the number of bricks, you have
to remember a simple formula i.e., Number
of bricks = Volume of brickwork/Volume of
1 brick with mortar.
For ease of calculations, I'm converting this
inch value into foot.
As we all knew that, 1 foot = 12 inches.
So, we have to divide these values with 12
to get the value in foot.
9/12=0.75 foot,
4.5/12=0.375 foot,
3/12=0.25 foot.
If you multiply these three values then you
will get it as 0.070 cubic foot.
So, one brick volume is 0.070 cubic foot.
Similarly, if you divide these values with
12 then you will get the volume of one brick
with mortar in cubic foot.
9.39/12=0.783,
4.89/12=0.408 foot,
3.39/12=0.283 foot,
So, if you multiply these three values then
you will get it as 0.090 cubic foot.
Now, we know the volume of one brick with
mortar.
Now, let's find out the volume of brickwork.
Volume of brickwork = length x height of the
wall x thickness of the wall.
length is 10 foot,
height is 6 foot,
and thickness is 4.5 inch.
4.5/12 = 0.375
So, if you multiply these three values then
you will get it as 22.5 cubic foot.
Therefore, volume of brickwork is 22.5 cubic
foot.
Now, we know the volume of brickwork and we
know the volume of 1 brick with mortar.
So, if you substitute these two value in this
formula then you will get the number of bricks.
Number of bricks equal to 22.5 cubic foot
/0.090 cubic foot.
which is equal to 250 no of bricks.
There will be some wastage in the field.
So, I'm considering 10 % brick wastage.
Therefore, no. of bricks equal to 250 + 10
% of 250, which is equal to 250+25 = 275.
So, including the wastage, you will be needing
275 no of bricks.
To calculate the quantity of cement, we must
know the quantity of mortar.
And how can you get the quantity of mortar?
Quantity of mortar = quantity of brickwork
- volume of the bricks.
So, if you deduct volume of bricks from the
brickwork then you will get the quantity of mortar.
We all ready lnow the quantity of brickwork,
which is volume of brickwork.
Now, let's calculate the volume of bricks.
Volume of bricks = no of bricks x volume of
1 brick.
Volume of one brick is 0.070 cubic foot, and
no of bricks is 250 (without wastage).
So, if you multiply these two values then
you will get the volume of bricks.
Which is 17.5 cubic foot.
Now, we know both values.
So, substitute these 2 values to get the quantity
of mortar.
Quantity of mortar = 22.5-17.5
which is equal to 5 cubic foot.
Let's say mix ratio is 1:5.
To get the dry volume of mortar, we have to
multiply wet volume with 1.33.
Which means dry volume of mortar is 33 % greater
than the wet volume of the mortar.
Dry volume =5x1.33 = 6.65 cubic foot.
There will be some wastage in the site, I'm
considering 5 % wastage of mortar.
So, Dry volume of mortar (including the wastage)
= 6.65 + 5 % of 6.65, which is equal to 6.65
+ 0.333.
If you add these two values then you will
get it as 6.983, which is approximately equal
to 7 cubic foot.
To get the quantity of cement you have to
remember a simple formula.
I.e., Dry volume of mortar x cement ratio/sum
of the ratios.
We know the dry volume of the mortar, I.e.,
7 and cement ratio is 1, divide it by cement
ratio i.e., 1 + sand ratio i.e., 5.
So,7 divide it by 6, which is equals to 1.166
cubic foot.
If you multiply volume with density of the
cement then you get thw weight of the cement.
and the density of cement is 1440 kg/m3.
Since density of cement is in the terms of
cubic meter, we have to convert the volume
of cement into cubic meter.
To do that we must know the relation between
cubic meter and cubic foot.
Here, one cubic meter= 35.3147 cubic foot.
So, if you divide this value with 35.3147,
then you will get the quantity of cement in
terms of cubic meter.
Therefore, quantity of cement = 1.166/35.3147
=0.0330 cubic meter.
Now, we know the volume of cement and we know
the volume of density of cement.
If you multiply these two values then you
will get the weight of cement.
I.e., the weight of cement =1440x0.0330=46.2
kg.
1 bag of cement contains 50kg of cement.
So if you divide these weight of cement with
50kg, then you will get the number of bags.
Therefore, number of bags = 46.2kg/50kg=0.924
no's.
Otherwise, you can say approximately 1 bag
of cement.
Similarly, we can calculate the quantity of
sand.
since, Cement and sand are in the ratio of
1:5.
If you multiply quantity of cement with 5
the you will get the quantity of sand.
therefore, quantity of sand = 1.166x5=5.83
cubic foot.
As I said earlier if you divide this cubic
foot value with 35.3147 then you will get the
volume in terms of cubic meter.
Therefore, quantity of sand equal to 5.83/35.3147
= 0.165 cubic meter.
I'm considering the density of sand as 1600kg/m3.
To calculate the weight of sand we have to
multiply density with volume.
So, 1600x0.165=264kg.
Otherwise, we can say 0.264tonnes.
To construct a wall of 10 foot long and 6-foot
height having the thickness of 4.5-inch you
will be needing 250 bricks and 1 bag of cement
and 264 kg of sand.
