**1. REQUIREMENTS**

a) Specified minimum strength = 20 N/Sq mm

b) Durability requirements

i) Exposure Moderate

ii) Minimum Cement Content = 300 Kgs/cum

c) Cement

(Refer Table No. 5 of IS:456-2000)

i) Make Chetak (Birla)

ii) Type OPC

iii) Grade 43

d) Workability

i) compacting factor = 0.7

e) Degree of quality control Good

**2. TEST DATA FOR MATERIALS SUPPLIED **

a) CEMENT

i) Specific gravity = 3.05

ii) Avg. comp. strength 7 days = 46.5 more than 33.0 OK

28 days = 55.0 more than 43.0 OK

b) COARSE AGGREGATE

i) 20mm Graded

Type Crushed stone aggregate

Specific gravity = 2.68

Water absorption = 1.46

Free (surface) moisture = 0

c) FINE AGGREGATE (Coarse sand)

i) Type Natural (Ghaggar)

Specific gravity = 2.6

Water absorption = 0.5

Free (surface) moisture = 1.4

**3. TARGET MEAN STRENGTH (TMS)**

a) Statistical constant K = 1.65

b) Standard deviation S = 4.6

Thus, TMS = 27.59 N/Sqmm

Advertisements

**4. SELECTION OF W/C RATIO**
a) As required for TMS = 0.5

b) As required for ‘Moderate’ Exposure = 0.55

Assume W/c ratio of 0.5

**5. DETERMINATION OF WATER & SAND CONTENT**

For W/C = 0.6

C.F. = 0.8

Max. Agg. Size of 20 mm

a) Water content = 186 Kg/cum

b) Sand as percentage of total aggregate by absolute volume = 35 %

Thus,

Net water content = 180.42 Kg/cum

Net sand percentage = 33 %

**6. DETERMINATION OF CEMENT CONTENT**

W/c ratio = 0.5

Water content = 180.42 Kg/cum

Thus, Cement content = 360.84 Kg/cum Adequate for moderate exposure Say 360 Kg/cum

**7. DETERMINATION OF COARSE AND FINE AGGREGATE CONTENT**

Assume entrapped air as 2 %

Thus,

0.98 cum = [180.42+360/3.05 + {1/0.33}*{fa/2.6}]/1000

& 0.98 cum = [180.42+360/3.05 + {1/0.67}*{Ca/2.68}]/1000

Hence,

fa = 584 Kg/cum

Ca = 1223.8 Kg/cum

The final mix proportions of M-20 grade of concrete become:-

Advertisements

Note: 1 The above recommended mix design must be verified, by actual cube tests.

2 The mix design is based on the quality and grading of the materials actually supplied, by the client.

Any variation in quality and gradation will result in changes in the mix design.

This mix design was submitted by a regular contributor to this site. We are thankful to him for his excellent service.

### Kanwarjot Singh

Kanwarjot Singh is the founder of Civil Engineering Portal, a leading civil engineering website which has been awarded as the best online publication by CIDC. He did his BE civil from Thapar University, Patiala and has been working on this website with his team of Civil Engineers.
If you have a query, you can **ask a question here**.

hello sir , i m a civil engineer and i need degine mix for m15, m20, m25, m 30 ..

sir”’

i need the design of mix for m15.,m20,m25,m30

Sir,

I’m a practicing civil engineer working with a private firm for highway consrtuction. I need all the design process & factors to be considered for the construction of bituminous & concrete road for highway,bridges,runways & taxiways.Please provide the necessary information as possible.

Regards,

Md.Faiz Ahmed

” Good Evening ”

Dear sir ,

I am Civil Engineer , i need concrete mix design for M20 and i also need the slump test range for conrete M20.

I am waiting for your response

Thanks

Please give an rough Idea about Concrete Mix Design of Grade M-25 at kolkata (salt lake) area.

thanks

Please forward the mix design of M20,M25,M30,M35,M40And M45 For blend 20mm with 12.5mm pumping

and 20mm weigh batching.

Please forward the mix design of M20,M25,M30,M35,M40And M45 For RCC.

Respected Sir

Pls give me details if M-20 in design mix and Voumetric 1:1.5:3 so how can calculate cement

And Sand and Coarse Agg quantity in normal process.

Thanks

Pradeep Srivastava

Dear sir/madam:

Im a civil engineer and i need concrete mix design of m15, m20, m25, m30 and also i have need calculation of RRC for roof and rings beam.

thanks for your cooperation

sir iam a civil engg student , iwant mix design of no fines concrete for m20 grade can you plz send

hello sir, i’m site superintendent, i need your help for reply me a concrete ration regarding site mix of concrete for grade 20 normal, 35 normal,40 normal, thank you so much

dear sir,

I know that what is M20,M250, M10, M150, concreate grade . Pl give us some guide line

with regards

devendra

sir pls sent M10,M15,M20,M25,M30 concrete mix ratio?

Hello sir i am a civil engineer plz send me a mix design of m5, m7.5, m10, m15, m20,25,35,40,45

Dear sir,

PLZ send the ratio of M15,M20,M25,M30 grade of concrete

thanx 4 ur helping

Dear sir,

PLZ send the ratio of M15,M20,M25,M30 grade of concrete.

hello sir

plz send me the mix designe for 210kg/cm2 as soon as p

regards.

kabul

afghanistan

Its very good website for civil Engineers. How to identify the TMT rod and what is the

allowable tollerence of 16mm rod

i am studying an civil engg.i need some tips for making concrete

Please send me mix design for M10,m15, m20,m25.

Please what is grade c concrete?