When I design RC beam using the Beams →Concrete module, the Asreq at the critical section changes drastically between 2.83 and 6.29 sq. in. depending on the number of bars I provided. As can be seen in the attached screenshot, the moment capacity is larger than the ultimate moment but the concrete module is reporting this as failing the code check.
I have spent several hours going through ACI 318-14 but could not identify which part of the code the design is failing on. Ram Element does not provide detailed design calculation or code references so that makes it even harder to crosscheck.
What I'm I missing here? I'm using Ram Element v16 Update 3 (16.03.01.8)
It seems like a code minimum area or spacing requirement is controlling here. If you send the file I can check that.
I have uploaded the files; "Pile Cap Design-Abut 1.rcb" and the original RAM Element file "Pile Cap Design-Abut 1.retx"
Update: It seems the file I uploaded is slightly updated to the 2.83 sq. in. option, but you can reproduce the screenshot in the original question if you change the Longitudinal reinforcement from #8 to #7.
Remember to send a zip file when using custom sections or materials. See Ram Elements Zipping a Model- https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/39895/zipping-a-model
I entered a new section and material based on your titles but mine works, output attached. Version 16.03.01.08 used.
PDF
Thank you for taking the time to look into this Seth. As you can see in the output you attached, Asreq is 2.83 but Asprov is 4.66 sq. in., a significant difference so far as what I'm working on is concerned. There are other reinforcement in the section so I want to reduce the longitudinal reinforcement as much as possible.
If you change the diameter of the bars from #8 to #7 for instance, Asreq suddenly increases from 2.83 to 6.29 sq. in, which was my original question. I get the same output you attached if I use #8 bars, it's just not feasible for the task at hand.
The output above is with 6 bars. I can reduce the bars to 4 and still pass the flexure check (see below), but the program won't pick this number of bars because of a spacing issue. - sb > sbmax