(Solved): Refer to the beam section from Problem 3.9. The tension steel consists of 8-30M bars. The contract ...

Refer to the beam section from Problem $$3.9$$. The tension steel consists of 8-30M bars. The contractor has misplaced the reinforcement such that the effective depth is reduced to $$440\mathrm{mm}$$. a) Find the factored moment resistance $$\left(M_r\right)$$ for the section. b) Determine whether the beam would fail in the steel-controlled mode or the concrete-controlled mode. c) Compare the $$M_r$$ values obtained in Problems 3.9, $$3.10$$, and $$3.11$$ and analyze the effect of the amount of steel and the neutral axis depth on $$M_r$$ value. Given: $$\begin{array}{rl}{f}_c^{?}& =30\mathrm{MPa}\\ f_y& =400\mathrm{MPa}\\ {?}_c& =0.65\\ {?}_s& =0.85\\ E_s& =200000\mathrm{MPa}\end{array}$$