Civil Engineering - Concrete Technology - Discussion

@All.

I only remember M20 which is 1: 1. 5:3 which is a different value from the rest.

So I will remember this then we will add more cement to go to m25, which is 1:1:2 ratio of cement and sand is the same. So here we have more cement. Then we will go to M15, which has less cement than M20.

And it should have more than 1. 5 sand, which is a 2:1:4 proportion. We will add more sand and aggregate to M10, which is a 1:3:6 proportion. Therefore, the quality of concrete is better in M25 and M20 than in M15 and M10.

Concrete Grade Proportion of Cement : Sand : Stone pieces.
Expected Compressive Strength at 28 days.

M100 ---> 1 : 3 : 6 10 N/mm^2 or 100 Kg/cm^2.
M15 or M150 ---> 1 : 2 : 4 ---> 15 N/mm^2 or 150 Kg/cm^2.
M20 or M200 ---> 1 : 1.5 : 3 ---> 20 N/mm^2 or 200 Kg/cm^2.
M25 or M250 ---> 1 : 1 : 2 ---> 25 N/mm^2 or 250 Kg/cm^2.

(IS 456-1964) = IS 456-1978)-------->Ratio.

M50 = M 5------------------- -> 1:5:10.
M75 = M7.5 -------------------> 1:4:8.
M100 = M 10 ---------------------> 1:3:6.
M150 = M 15 --------------------> 1:2:4.
M200 = M 20----------------- -> 1:1.5:3.
M250 = M 25 ------------------> 1:1:2.

Answer will be none of these, because above M25 as per Indian Standard are mix design, not nominal mix it. It uses, wherever we need to achieve desired strength as per project or clients need.

M10 - 1:3:6.
M15 - 1:2:4.
M20 - 1:1.5:3.
M25 - 1:1:2.
1:4:8
M30 - 1:5:10
1:6:12.
M35 - post-tensioned prestressed concrete.
M40 - pre-tensioned prestressed concrete.

Question is wrong because M150 is design mix concrete so by can not determine the actual ratio. It is vary according to our structure type and 1:1:2 is proportion of M25.

@Karmveer is right. M150 is design Mix Not Nominal mix so we cannot determined the actual ratio. & 1:1:2 is the proportion of M25.

M 5 = 1:5:10
M 7.5 = 1:4:8
M 10 = 1:3:6
M 15 = 1:2:4
M 20 = 1:1.5:3
M 25 = 1:1:2
M 30 = 1: 1:3
Correct answer is C .

M150 means 150 kg/cm2 as per IS 456:1978.

After revision IS 456:2000 IS M15.
So, the correct option is 1:2:4.

As per IS 456-2000.

M 5 =1:5:10.
M 7.5 =1:4:8.
M 10 =1:3:6.
M 15 =1:2:4 Ans.
M 20 =1:1.5:3.
M 25 =1:1:2.