Civil Engineering - Concrete Technology - Discussion

Both D and E is correct.

I think both D & E are correct answer because according to arbitrary method of proportioning. The proportioning should be 1:n:2n.

Because we did not seen any where 1:4:10 in our code books.

1 : 2 : 8 & 1 : 4 : 10 these are wrong because does not satisfy the general relation 1 : n : 2n.

Thank you very much for the explanation, but what about ACI METHOD?

For this, methods of proportioning is applicable and given by 1:n:2n.

Answer is both D & E because according to arbitrary method of proportioning. The proportioning should be 1:n:2n.

@S.Raghuraman Sir.

Can you please give details as on how we should not encourage 1:2:8 & 1:4:10 mixes in the field and how they would develop honey comb and instability in strength.

Because it not satisfying the 1:n:2n. For arbitrary method.

Both 1:2:8 and 1:4:10 are wrong proportions.

1:1:2 - M25.
1:2:4 - M15.
1:3:6 - M10.

1:2:8 - Wrong proportion, it should be 1:4:8 for M7.5.
1:4:10 - Wrong Proportion, it should be 1:5:10 for M5.

Hence the correct answer is Both Option D and E,. I think they have mistakenly wrote 1:2:8 instead of 1:4:8 , as it does not have any option to give both D and E as correct answer.

And regarding our IS : 456-2000 , there is no such provision given for Volume Batching, as our code says criteria only about Weight Batching and there Relative Proportions, But the above proportions are Nominal Mix Proportions which are used for Volume Batching Only, hence we don't have seen such Proportions on IS Code.