Question:medium
Maximum longitudinal reinforcement in columns shall not exceed ____
Maximum longitudinal reinforcement in columns shall not exceed ____
Show Hint
IS 456 limits for longitudinal reinforcement:
\[
\boxed{
\begin{aligned}
\text{Minimum} &=0.8\% \text{ of gross area}\\
\text{Maximum} &=6\% \text{ of gross area}
\end{aligned}
}
\]
(Practically, about \(4\%\) is preferred to avoid congestion.)
Updated On: Jul 23, 2026
- \(6\%\) of effective sectional area
- \(4\%\) of gross sectional area
- \(6\%\) of gross sectional area
- \(4\%\) of effective sectional area
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: recall why IS 456 places a cap on longitudinal steel at all.
Too much longitudinal steel packed into a column section makes it very hard to place and compact concrete properly around the bars, so the code fixes both a lower and an upper limit for practical reinforcement detailing.
Step 2: recall the exact limits from clause 26.5.3.1 of IS 456.
The minimum longitudinal steel is fixed at $0.8\%$ and the maximum is fixed at $6\%$, and both these percentages are always expressed as a fraction of the gross cross sectional area of the column, not the effective or net concrete area.
Step 3: match this to the given options.
This rules out any option based on effective sectional area or a $4\%$ figure.
\[ \boxed{6\% \text{ of gross sectional area (option C)}} \]
Too much longitudinal steel packed into a column section makes it very hard to place and compact concrete properly around the bars, so the code fixes both a lower and an upper limit for practical reinforcement detailing.
Step 2: recall the exact limits from clause 26.5.3.1 of IS 456.
The minimum longitudinal steel is fixed at $0.8\%$ and the maximum is fixed at $6\%$, and both these percentages are always expressed as a fraction of the gross cross sectional area of the column, not the effective or net concrete area.
Step 3: match this to the given options.
This rules out any option based on effective sectional area or a $4\%$ figure.
\[ \boxed{6\% \text{ of gross sectional area (option C)}} \]
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