M-25 GRADE CONCRETE MIX DESIGNDATAS REQUIRED:

1. Characteristics compressive strength @ 28 days=25 N/mm22. Maximus size of Aggregate

=20mm

3. Required slump

=100mm

4. Type of exposure

=severe

5. Chemical Admixture

=Nil

6. Absorption

a. 20mm

=0.6 %

b. NRS

=1.5 %7. Specific gravitya. Cement

=3.15

b. 20mm

=2.79c. NRS

=2.65 Zone III1. Target mean strength

fck=fck + 1.65s

=30 + 1.65(4)fck=36.6 N/mm22. Selection of Water-Cement ratio

From IS:456-2000 table 5, max. free w/c for M25 = 0.53. Selection of Water content

From IS:10262-2009 table 2, max water content = 186 Kg

For 100mm slump water content to be increased by 6 % = 197 Kg

4. Calculation of Cement content

Cement content = 197/0.5 = 388 Kg.

From table 5, min. cement content for M25 = 300 Kg.

388 > 300 Kg.

5. Proportion of volume of CA and FA

From IS:10262-2009 table 3,

vol of CA per unit vol of total aggregate for zone III = 0.64

vol of FA = 1-0.64 = 0.36

6. Mix calculations

a) Vol of Concrete=1 m3b) Vol of Cement

=0.123 m3c) Vol of water

=0.197 m3d) Vol of all in aggregate=0.68 m3e) Mass of CA

=1214 Kg

f) Mass of FA

=650 Kg

Mix proportion for 1 m3

Correction for AbsorptionCement= 388 Kg

388 Kg

Water

= 197 Kg

201 Kg20mm

= 1214 Kg

1207 KgNRS

= 650 Kg

640 Kg