CONCRETE MIX DESIGN M30 GRADE IS-10262-2009

Concrete mix design is required to obtained target strength in building and structures. Concrete Mix design of M30 grade of concrete can be find from the example given below.

1.Design Stipulation For Proportioning

Grade Designation = M-30

Type of cement = OPC 53 grade confirming to IS-12269-1987

Exposure condition = Normal (for reinforced concrete)

Method of placing = Pumping 

Degree of supervision = Good

Maximum nominal size of aggregate = 20 mm

Maximum Cement content =540 kg/m³

Minimum Cement content = 310 kg/m³

Maximum water cement ratio = 0.45

Workability = 50-75 mm (Slump)

Type of aggregate = Crushed angular aggregate

Chemical admixture type = Superplasticiser

2. Test Data For Material

Cement used = Coromandal King OPC 53 grade

Sp. Gravity Cement = 3.15

Sp. Gravity Fine Aggregate = 2.61

Sp. Gravity Coarse Aggregate (20mm) = 2.88

Sp. Gravity Coarse Aggregate (10mm) = 2.868

Chemical admixture = Superplasticiser confirming IS 9103

Water absorption of coarser aggregate(20mm) = 0.97%

Water absorption of coarser aggregate(10mm) = 0.87%

Free surface moisture = Nil

Sp. Gravity of Combined Coarse Aggregates = 2.882

3. Target Mean Strength

Himsworth constant for 5% risk factor is 1.65. In this case standard deviation is taken from IS:456 against M 30 is 4.0.

f_target = f_ck + 1.65 x S

Target Mean Strength = 42 Mpa

Where,

S = standard deviation in N/mm² = 4 (as per table -1 of IS 10262- 2009)

4. Selection of water cement ratio

Maximum Water Cement Ratio = 0.45

Adopted Water Cement Ratio = 0.42

 

5. Selection Of Water Content

Maximum Water content (10262-table-2) = 186 ltr

Estimated Water content for 50-75 mm Slump = 160 ltr

Superplasticiser used = 0.5 % by wt. of cement

6. Cement Content Calculation

Water Cement Ratio = 0.42

Cement Content (160/0.42) = 380 kg/m³

Corrected water content = 160 ltr

Cement content =

From Table 5 of IS 456,

Minimum cement Content for mild exposure condition

= 310 kg/m³

380 kg/m³ > 300 kg/m³, hence, OK.

This value is to be checked for durability requirement from IS: 456.

In the present example against mild exposure and for the case of reinforced concrete the minimum cement content is 310 kg/m³ which is less than 380 kg/m³. Hence cement content adopted = 380 kg/m³.

As per clause 8.2.4.2 of IS : 456

Maximum cement content = 540 kg/ m3

7. Calculation of sand and coarse aggregate

From Table 3 of IS 10262- 2009,

For Nominal maximum size of aggregate = 20 mm,

Zone of fine aggregate = Zone II

And For w/c = 0.42

Vol. of C.A. as per table 3 of IS 10262 = 62%

Adopted Vol. of Coarse Aggregate = 62%

Adopted Vol. of Fine Aggregate ( 1-0.62) = 38% 

8. Estimation of the mix ingredients

Volume of Concrete in m^{3 = 1.0}

Volume of cement in m3 = 0.12

(Mass of Cement) / (Sp. Gravity of Cement)x1000

Volume of water in m3 = 0.160

^{(Mass of Water) / (Sp. Gravity of Water)x1000}

^{Volume of Admixture 0.5% in m3 = 0.00160}

^{(Mass of Admixture)/(Sp. Gravity of Admixture)x1000}

^{Volume of All in Aggregate in m3 = 0.718}

^{Serial. number. 1 – (Sr. no. 2+3+4)}

^{Volume of Coarse Aggregate in m3 = 0.445}

^{Serial. number. 5 x 0.62}

^{Volume of Fine Aggregate in m3 = 0.273}

^{Serial. number. 5 x 0.38}

^{Mix Proportions for One Cum of Concrete}

^{Mass of Cement in kg/m3 = 380}

^{Mass of Water in kg/m3 = 160}

^{Mass of Fine Aggregate in kg/m3 = 711} 

^{Mass of Coarse Aggregate in kg/m3 = 1283}

^{Mass of 20 mm in kg/m3 = 924}

^{Mass of 10 mm in kg/m3 = 359} 

^{Mass of Admixture in kg/m3 = 1.9} 

^{Water Cement Ratio =0.42}