Consider the elevation view of an interior beam shown below. The beam has a t$-$shaped cross$-$

section $($the $5in.$ thick slab is cast monolithically with the beam $-$ meaning that the $22in.$ deep

beam has $17in.$ hanging below the slab$).$ The c$-$c length is $30ft.$

Assume:

$b_w=14in.,h=22in.$

$f_c^{\text{'}}=6$ksi,$f_y=60$ksi

$M_{u,\text{n}\text{e}\text{g}\text{.}}=340k*ft,M_{u,\text{p}\text{o}\text{s}}=230k*ft$

$l_n=28\mathrm{.}5ft,s_w=12ft$

$h_{\text{s}\text{l}\text{a}\text{b}}=5in.$

No$.4$ stirrups

a$.$ Select flexural reinforcement for the beam at midspan assuming it is singly reinforced. T$-$

beams under positive bending are usually singly reinforced because the depth of the neutral

axis in the flange is often smaller than the depth of any bars that might be present. Iterate

until the design strength, $M_n,$ exceeds $M_u$ by less than approximately $20\%.$ Provide a

drawing of the section design that clearly shows the location of the longitudinal

reinforcement. Show the section complies with relevant ACI Building Code requirements

$,$ bar spacing limits$,\{$:${}_{t,\text{m}\text{i}\text{n}}).$

b$.$ Select flexural reinforcement for the beam at the left support assuming it is doubly$-$

reinforced. T$-$beams under negative bending are often doubly reinforced because the depth

of the neutral axis in the web is often larger than the depth of any bars that are present.

Iterate until the design strength, $M_n,$ exceeds $M_u$ by less than approximately $20\%.$

Provide a drawing of the section design that clearly shows the location of the longitudinal

reinforcement. Show the section complies with relevant Code requirements $,$ bar

spacing limits$,{}_{t,\text{m}\text{i}\text{n}}).$