Why are code requirements regarding minimum spacing, cover and area of reinforcement necessary to observe in concrete structures? $(5$marks$)$

A simply supported concrete beam section of $250$mm by $500$mm spanning $5$ meters carry a uniformly distributed dead load of $50$ kN$/$m and imposed load of $14\mathrm{.}06$ kN$/$m$.$ Determine flexural and shear reinforcement, given the characteristic material strengths are f f ck $2$ yk $=500$Nmm $,=25$Nmm$-2,$ nominal cover to main reinforcement bars is $40$mm and assume bar diameter $20$mm for main bars and $8$mm for links.