Using the ASSHTO section configuration shown in the figure $($ASSHTO Girder III$),$ redesign the beam of Problem $2$ if the span of the beam is reduced to $20\mathrm{.}0m.$ Use a draped profile for the bonded tendon.

Determine the limiting envelope for the tendon location. Consider the mid$-$span, quarter$-$span, and beam ends as the controlling sections for estimating the tendon profile. Use low relaxation seven$-$wire strands with $f_{pu}=1860$MPa.

$A_c=365{10}^{3}m{m}^2,$

$I_c=53{10}^{9}m{m}^4,$

$r^2=145205m{m}^2,$

$c_t=628mm,$

$c_b=517mm,$

$S_t=84{10}^{6}m{m}^3,$

$S_b=102\mathrm{.}5{10}^{6}m{m}^3,$

$f_c^{\text{'}}=45$MPa and

$f_{ci}=35$MPa.