XAMPLE $2$

GIVEN:

MATERIALS: NW CONCRETE $40$sopsi

GR GO STEEL

SECTION W$/$ REINFORCEMENT

REQ'D

Determine crackina MOMENT Mar With tuE ACI $318$ Method $($GROSS section$)$

SOLUTION

$=\frac{M_c}{(\frac{?}{\text{b}\text{a}\text{r}}(I))}{M}_{cr}=f_r\frac{I_g}{c}$

$f_r=7\mathrm{.}5\sqrt[\phantom{2}]{f_c^{\text{'}}}=7\mathrm{.}5(1\mathrm{.}0)\sqrt[\phantom{2}]{4000}=474$

For $I_g,$ break section in parts

$\backslash$table$[[$PART$,\frac{?}{\text{b}\text{a}\text{r}}(y{)}_i(in),A_i(i{n}^2),\frac{A_i}{b}ar(y{)}_i(i{n}^3),A_i(\frac{?}{\text{b}\text{a}\text{r}}(y{)}_i-(\frac{?}{\text{b}\text{a}\text{r}}(y)){)}^2(i{n}^4),I_i(1i{n}^4)$