Civil Engineering - RCC Structures Design - Discussion


As the percentage of steel increases

[A]. depth of neutral axis decreases
[B]. depth of neutral axis increases
[C]. lever arm increases
[D]. lever arm decreases
[E]. none of these.

Answer: Option B


No answer description available for this question.

Ami said: (Oct 4, 2013)  
With increase in % of steel, section tends to become over reinforced. And concrete tends to fail prior to steel.

Krishna Rai said: (Jul 30, 2014)  
Because if steel is increased the tensile strength is increased manifold so large compressive force is required to counteract this force. Larger comp.force larger nu.depth.

Ranjan Patra said: (Jun 24, 2016)  
PT% = 100 AST/BD.

Then the answer is option A.

Dvs said: (Aug 13, 2017)  
@Ranjan they didn't ask EFFECTIVE DEPTH of the slab.


Ashley said: (Dec 15, 2017)  
D can be correct as NA increase LA decreases.

Dhl said: (Dec 15, 2017)  
Lever arm decreases.

So, Both are true.

Vroom said: (Feb 7, 2018)  
%steel propotional to NA.

Suresh Chandra said: (Apr 16, 2018)  
Lever arm decrease and Neutral axis increases.

Sopori said: (Apr 30, 2018)  
If steel is increased in the tensile zone, then the neutral axis will move down in the beam, (depth of N-axis will increase).

Roy said: (Nov 20, 2018)  
Yes, both B&D are correct @Ashley.

King said: (Apr 10, 2020)  
Only option B is correct because the Neutral axis is compared with the critical Neutral axis to decide to decrease or increase. But the level arm is not compared with any critical level arm. In IS code definition of the critical level arm is not describe anywhere.

So, only option B is correct.

Jadeja Divyarajsinh said: (Feb 24, 2021)  
Xu (depth of N.A.) = 0.87fyAst/0.36fckb.
So, Xu proportional to Ast,
Increase with Ast.

Post your comments here:

Name *:

Email   : (optional)

» Your comments will be displayed only after manual approval.