Civil Engineering - RCC Structures Design - Discussion

It should not exceed more than 4%.

Because it's uneconomical.

@Mukesh.

You can calculate minimum tension requirement in fe500 by the formula given by the code (Cl.26.5.1).
i.e; (Ast)min.= .85bd/fy.

If the % age of tension steel is more than 4 than the failure of concrete occur early than the failure of steel. Thus if this happens the failure occurs immediately as the concrete has no yield point it collapse immediately which is not safe. Thus Ast should not be more than 4%.

The BS 8110 the area of steel reinforcement in tension, denoted as should not exceed 4%.

The maximum area of tension reinforcement should not exceed 4%. It is because of congestion of reinforcement & also proper compaction of concrete will not be possible.

Further, excess reinforcement will cause concrete or brittle failure which is sudden & without notice which causes huge loss of property/manpower. Hence, the restriction of 4% in tension zone.