Ram Concept -PT/Podium Design

[bdlc2k]

Hey, everyone
We use Ram Concept for PT design. In a PT/Podium project, we typically balance 100-125% of the dead load because of the upper floors weighing down on the slab. When looking at the output, the slab deflections, moments..etc.. look ok. However, when we look at the Design Strip->"Balanced Load Percentages", they don't usually match the desired percentage, especially when we changes the tendon profile to match a prelim design hand calc (Under the Manual tendon layout->Current Balanced Load vs Desired Balanced Load.) Does anyone have any comments/suggestions about properly interpreting or using the Tendon Balancing tool and the Balance Percentages when looking at the output? Which should govern? Achieving the DL Balance Percent in Design Strip or the Tendon Balancing?

Also, a quick question on column detail--where does the bottom reinforcing at the column come from? I don't see an references that discuss this (see attached detail)
Thanks!

 

[dcarr82775]

I can't speak to the RAM side of things, but ACI318 requires bottom bars at the columns.

 

[asixth]

I don't get too wrapped up in load-balancing and rely more on the suggest P/A limits and detail the tendons to best match the slab moments.

If the cross-section is working too hard and has a very high neutral axis it may be putting in compression reinforcement in the bottom face over the columns.