Correct Answer - Option 2 : 0.48
Concept:
The ratio of limiting depth of neutral axis to the effective depth of the beam is given by
\(\frac{{{x_u}}}{d} = \frac{{{\rm{Max\;strain\;concrete}}}}{{\frac{{{\rm{Grade\;of\;steel}}}}{{{\rm{Modulus\;of\;Elasticity\;of\;steel}} × {\rm{F}}.{\rm{O}}.{\rm{S}}}} + 0.002 + {\rm{Max\;strain\;concrete}}}}\)
Note:
We know the standard values of the ratio of limiting depth of neutral axis to the effective depth (k) of the beam for different steel sections as following:
xu = k × d
Grade of Steel
|
Fe 500
|
Fe 415
|
Fe 250
|
‘k’ value
|
0.46
|
0.48
|
0.53
|
∴ For Fe415 grade limiting value of depth of neutral axis is 0.48×d