An $RC$ beam, with the cross section below, is required to resist a total applied design moment $M_{Ed}=676kNm$

Its ultimate moment of resistance $M_u=425kNm$

Its effective depth $d=355mm$ and $d_2=53mm$

Calculate the area of primary tensile steel $A_S$ required to resist this applied moment.

Give your answer in $m{m}^2$ to the nearest whole unit. Do not include units in the answer box.

Assume that $k_{\underset{?}{lim}}=0\mathrm{.}167.$

To calculate $z$ in relation to tension steel for $M_u,$ you must use $z=0\mathrm{.}82xd($do not attempt to work out $z$ using $k$ and the formula $\frac{z}{d}$ etc.$).$

er $5,267$ margin of error $\frac{+}{-}2\%$

The final answer is equal to $5267$ mm$^2$