# Civil Engineering - Concrete Technology - Discussion

Discussion Forum : Concrete Technology - Section 3 (Q.No. 1)
1.
Permissible compressive strength of M 150 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
300 kg/cm2
Explanation:
No answer description is available. Let's discuss.
Discussion:
28 comments Page 1 of 3.

Bharath E said:   8 years ago
It is 150 kg/cm^2 only. Option B is correct. Don't confuse between permissible and ultimate strength.

If we design the mix for M150 grade means permissible will be 150kg/cm^2 only. Sometimes during testing due to some variations strength decreases for ex.130 or 135kg/cm^2 or 200kg/cm^2 even if we designed for M150 grade concrete. But we designed for M150 means we must conclude the answer to be 150kg/cm^2 irrespective of what ever we obtained.

In SCC sometimes permissible strength varies due to trail and error Mix design methods,but here they didn't mention anything as SCC(Self Compacting Concrete)
Finally, option B is correct.

Hope this will clear the confusion.

Raviraj Patel said:   7 years ago
It's 150 because M150 means M denotes design mix of concrete and 150 denotes the permissible comprehensive strength of concrete after 28 days of 150mm cube.

Like GRADE OF CONCRETE- CSO CONCRETE
M15 15
M20 20 Etc

Makvana Disha said:   7 years ago
Here, permissible strength is required to be determine fck 150 is already given. So, permissible strength= fck/partial safety factor.

150/1.5 = 100 kg/sq.cm.

fck = characteristic compressive strength of concrete at 28 days after curing.

Pusp Raj Bhatt said:   8 years ago
Answer should be 37.5Kg/cm2 for direct compression and 40Kg/cm2 for bending compression, 150 is Characteristic strength not permissible.

Vivek Rauniyar said:   9 years ago
For M150 the compressive is 150 kg/cm2 but this is ultimate compressive strength not permissible compressive strength.

Pankaj said:   7 years ago
100 kg/cm2 is the right answer because we allow it after failure in compressive standard unit.

I know that compressive strength of M150 is 150kg/cm2, but it is 200kg/cm2 how?