For calculating the quantities of cement,sand and aggregates required for 1㎥ , Let me assume any nominal mix grade of concrete as

**M-20.(Nominal mix)****Concrete mix design for M-20 (1:1.5:3) grade of concrete:**

As we know that when we pour wet concrete during concreting, it hardens after certain standard time. In view of this, it was decided by the Civil Design Engineers to take a factor of safety from 1.54 to 1.57 .

so we can say, Volume of dry concrete = 1.54 to 1.57 times the volume of wet concrete

I m assuming

**1.54**as a safety factor
Therefore, the total volume of concrete required is 1.54㎥.

As per IS456:2000, M-20 Grade concrete proportion is = 1 : 1.5 : 3

Remember, here (1:1.5:3) indicates:

1 for cement

1.5 for sand

3 for aggregate

Total volume (cement + sand + aggregate) = 1 + 1.5 + 3 = 5.5

#### Calculation of Volume of Cement in 1㎥ of Concrete

Volume of cement= (cement/cement+sand+aggregate) x 1.54

Quantity of cement= (cement/total volume) x1.54

= (1/5.5)x1.54

= 0.28 ㎥

we know , Volume of a one cement bag =0.0347 ㎥

Thus Total no. of bags required for 1 ㎥ =0.28/0.0347

= 8 .06 (i.e 8 bags approx.)

Hence, we require 8 bags of cement for 1 cu.m of concrete.

As we know, 1 Bag of cement weighs 50 kg (one bag of cement)

so For 1㎥ of concrete we have ,

Total no. of bags required x 50 kg of cement = 8 x 50 = 400 kg

**For 1㎥ of Concrete = 400 Kgs of Cement is required**

#### Calculation of Volume of Sand (Fine Aggregate) in 1㎥ of Concrete:

Volume of sand= (sand/cement+sand+aggregate) x 1.54

Quantity of sand = (sand/total volume) x1.54

= (1.5/5.5)x1.54

= 0.42 ㎥

1㎥ of sand = 1600-1800 kg

Assume 1650 kg

0.42㎥ of sand =1650 x 0.42

= 693 kg

The volume of sand increases as it contains moisture.For accurate calculation use dry sand.

**Hence we require 693 kg of sand for 1 cu.m of concrete.**

#### Calculation of Volume of Coarse Aggregate in 1㎥ of Concrete:-

Volume of aggregate= (aggregate/cement+sand+aggregate) x 1.54

Quantity of aggregate= (aggregate/total volume) x1.54

= (3/5.5)x1.54

= 0.84 ㎥

1㎥ of sand = 1500-1800 kg

Assume 1600 kg

0.84㎥ of sand =1600 x 0.84

= 1344 kg

If void spaces decreases,density of aggregate may go higher.

**Hence we require 1344 kg of aggregates (20 mm) for 1 cu.m of concrete.**

**Water required for 1㎥ of concrete: -**

Water is added for making the concrete mass and it depends upon the climatic conditions whether hot or cold weather and workability.

We typically maintain a 0.35–0.50 to water cement ratio. Remember, the above values may change according to the moisture content present in the sand and aggregates.

#### Cement Required for 1㎥of Concrete = 400Kgs

####
Assume W/C ratio = 0.45
Water required for 1㎥ of Concrete = 400 x 0.45

#### Amount of water required for 1㎥ of Concrete = 180 kgs = 180 litres.

**Hence 180 Litres of Water is required for**

**1㎥**

**of M20 Concrete.**

Summary: –

8 bags of cement required for 1 cu.m of M-20 grade. concrete.

693 kg of Sand required for 1 cu.m of M-20 grade concrete.

1344 kg of 20mm Aggregate is required for 1 cu.m of M-20 grade concrete.

180 litres of water is required for 1 cu.m of M-20 grade concrete.

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