### Material estimation for M25 grade concrete. / Estimation of cement, sand, & aggregates in M25 ( 1:1:2 mix ratio) concrete.

Let us consider 1 CUM of M25 grade concrete for the calculation purpose.

Here,

Cement:sand: aggregates = 1:1:2 (a:b:c)

M25 grade means 👉  1:1:2 ratio.

Wet volume of  M25 grade concrete = 1 CUM.

Now, dry volume of concrete

= [1.54 × 1 cum] = 1.54 cum.

1. Volume of  cement required

= [{its ratio  ÷ (total ratio)} × dry volume of concrete.]

=[{ a ÷ (a + b + c)} × dry volume of concrete.]

= [{1÷ ( 1 + 1 +2 )} × 1.54]

= [{ 1 ÷ 4 } × 1.54]

= [0.25 × 1.54]

=  0.385 cum.

As you know, 1 bag of cement = 0.03472 cum.

So, the number of cement bags required

= [0.385 cum. ÷ 0.03472 cum.]

= 11.089 bags

Weight of cement

= [11.089 bags × 50 kgs.]

(1 bag of cement = 50 kgs.)

554.44 kgs.

2. Volume of sand required

= [{its ratio  ÷ (total ratio)} × dry volume of concrete.]

=[{ b ÷ (a + b + c)} × dry volume of concrete.]

= [{1÷ ( 1 + 1 +2 )} × 1.54]

= [{1 ÷ 4 } × 1.54]

= [0.25 × 1.54]

=  0.385 cum.

=  13.60 cu ft.

3. Volume of aggregates required

= [{its ratio  ÷ (total ratio)} × dry volume of concrete.]

=[{ c ÷ (a + b + c)} × dry volume of concrete.]

= [{2÷ ( 1 + 1 +2 )} × 1.54]

= [{ 2 ÷ 4 } × 1.54]

= [0.5 × 1.54]

=  0.77cum.

= 27.19 cu ft.

4. Volume of water required.

Let us consider the w/c ratio for M25 grade concrete as 0.4.

i.e. wt. of cement / wt. of water = 0.4

So, the weight. of water

= 0.4 × wt. of cement

=0.4 × 554.44 kgs

= 221.776 kgs

= 222 liters

( 1kg= 1 liter)

Note: This w/c ratio holds good if you use plasticizers. Practically for good workability, the water we add for the concrete is 250 to 270 liters.

#### Alternate method:

1. Volume of cement ( from above) = 0.385 cum.

2. Volume of sand

= [volume of cement × b]

=   [0.385 cum × 1]

= 0.385 cum.

3.  Volume of aggregates

= [volume of cement × c]

= [ 0.385cum × 2]

= 0.77 cum.

Now, let us put these material quantities in a table format for easy reference.

 Materials in 1CUM of M25 grade concrete. Sl. No. Item Unit In cum. In cu ft. 1. Cement bags 11.089 bags - 2. Sand - 0.385 13.60 3. Aggregates - 0.77 27.19 4. Water litres 222 -

Next part 👇

What will be the cost of M25 grade concrete ?/How to calculate the cost of concrete having a 1:1:2 mix ratio?