How to determine the volume of cement & sand in mortar and number of bricks


This tutorial video is very useful and informative for civil engineering students. By watching this video, one can learn how to work out the numbers of bricks and the cement and sand quantities in mortar for 1m3.

The video focuses on the following points:-

The dimension of modular brick is 19 x 9 x 9 cm (Length x Breadth x Height).

The thickness of mortar in brickwork is 10 mm = 1 cm

Once the mortar is applied to brickwork, the dimension of the brick will be changed to 20 x 10 x 10 cm

The mortar is formed with cement and sand and their ratio is 1:6

Initially, it is required to determine the volume of 1 brick as follow:-

Volume of brick = 20 x 10 x 10 cm = .20 x .10 x .10 = 0.002 m3

Now, determine the number of bricks in 1m3 as follow:-

1/0.002 m3 = 500 numbers

Now, work out the volume of 1 brick devoid of mortar as follow:-

Volume of 1 brick without mortar = 19 x 9 x 9 cm = .19 x .09 x .09 = 0.001539 m3

Now, it is required to determine the volume for 500 numbers of bricks in 1m3 as follow:-

Volume of 1 brick = 0.001539 m3

So, for 500 bricks, the volume will be = 500 x 0.001539 = 0.7695 m3

So, volume of mortar in 1m3 = 1 – 0.7695 = 0.2305 m3

As the mortar is wet at that time, so, the output is in wet volume.

It is required to convert to dry volume. 33% is increased when converted to dry volume.

So, 0.2305 x 1.33 (133/100) = 0.306 m3

So, it is the weight of mortar in dry condition.

Now, the volume of cement and sand will be determined as follow:-

The ratio is 1:6 (one part cement and 6 part sand)

The volume of cement = 0.306 x 1/7 (as 1+6 = 7) = 0.043 m3

The density of cement = 1440 kg/ m3

So, the volume of cement in kg will be = 0.306 x 1/7 x 1440 = 62 kg (approx).

We know, the weight of 1 bag cement = 50 kg

So, the number of bags = 62/50 = 1.24 bags

The volume of sand = 0.306 x 6/7 = 0.262 m3

Now, it is required to covert from kg to cft. For this purpose, you have to multiply with 35.3147.

So, 0.262 x 35.3147 = 9.25 cft

Now, we know, the density of sand = 1450 kg/ m3

So, the volume of sand in kg = 0.262 x 1450 = 379.9 kg

To get more details, go through the following video tutorial.

Video Courtesy : TIMES OF KNOWLEDGE

Mortar