Hi,
I am trying to design prestressed concrete 78" Girder with 8.25" Slab thick. my Prestressing steel centroid is Ypg=9.88 in and total section height H=86.25"
so my dp=H- ypg=86.25-9.88=76.37". I have no mild reinforcement in the girder, so dp=de. The program is calculating de to be 83.03", and i would like to know why the reason for that?
Per AASHTO 9ed
Thank you
Ashvin