The architect has specified a $200mm$ thick concrete

slab cast with the patterns shown as a feature ceiling.

The slab is reinforced with $15M$ bars at $250mm$

spacing $(15$M@$250).$ Use an effective depth of

$170mm.$ The concrete and steel material properties

are given below.

a$)$ Find the factored moment resistance per metre

width of the slab.

b$)$ Draw the slab cross$-$section showing the con$-$

crete compression zone.

Given:

$f_c^{\text{'}}=25$MPa

$f_y=400$MPa

${}_c=0\mathrm{.}65$

${}_s=0\mathrm{.}85$

$E_s=200000$MPa