Question $02$:

Design rectangle prestressed concrete section with parabolic tendon and with a span of $20m$ using ACI $318$ allowable stresses. The beam has to carry a superimposed sustained service live load of $16\mathrm{.}1k\frac{N}{m}$ and superimposed dead load of $1\mathrm{.}5k\frac{N}{m}.$ Assume the beam is made of normal weight concrete with $f^{\text{'}}{?}^{\text{'}}=40$MPa and the concrete strength $f_{ci}^{\text{'}}$ at transfer is $75\%$ of concrete strength $f^{\text{'}}{?}^{\text{'}}.$ The time dependent losses are $15\%$ of the initial prestress. $f_{pu}=1862$MPa. The allowable tensile stress $f_t=\sqrt[\phantom{2}]{f^{\text{'}}}*f_{}=0\mathrm{.}70f_{pu}$

Question $03$:

Design Problem in Question $2$ for Shear.

Question $04$:

Determine the design moment capacity $\frac{O}{M_n}$ of the prestressed concrete rectangular section in Question $2.$ check the safety of the section to resist the ultimate moment developed.