Practical Application of RAM Concept
Practical Application of RAM Concept
(OP)
Hey Everyone,
I'm writing to see who (if anyone) uses RAM Concept for the design of two-way concrete slabs. I find that the program is able to give me solutions, but not completely practical ones. Is there anyone out there who uses this program to regularly design and compile their drawings? And if so, maybe we could exchange email address to discuss?
Thanks in advance.
I'm writing to see who (if anyone) uses RAM Concept for the design of two-way concrete slabs. I find that the program is able to give me solutions, but not completely practical ones. Is there anyone out there who uses this program to regularly design and compile their drawings? And if so, maybe we could exchange email address to discuss?
Thanks in advance.






RE: Practical Application of RAM Concept
I agree that trying to design reinforcement using design strips is mostly useless.
RE: Practical Application of RAM Concept
I guess my next logical question would be, if no one is really using concept, what is everyone using?
RE: Practical Application of RAM Concept
It just takes time to find out what it does well and what it doesn't do well.
RE: Practical Application of RAM Concept
RE: Practical Application of RAM Concept
RC Slabs
- Gives less deflection than what it should (unconservative).
- Gives higher flexural reinforcement than what it should (conservative).
Post-Tensioned Slabs
- Returns a higher deflection (conservative).
There is no difference in using a design strip or cutting a section for your design. Most detailing comes down to peak flexural design and peak shear design after the slab thickness is established. The peak moments and shears are reinforced and the engineer determines where and how the reinforcement is curtailed back to minimum requirements.
RE: Practical Application of RAM Concept
I've designed and built a few dozen of these. No issues. I'm not losing sleep over it either.
When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.
-R. Buckminster Fuller
RE: Practical Application of RAM Concept
Obviously, a rectangular grid works best. Sometimes you get odd reinforcing results, you need to learn how to interpret these and what the "bugs" are.
For weird sized strips and supports, it does take a little bit of judgement to lay out the bar.
But for standard bays and strips, I generally use the results that it provides.
When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.
-R. Buckminster Fuller
RE: Practical Application of RAM Concept
I guess that was the main thing i was looking for. Output. It's an amazing analysis tool, I was just looking for a way to transfer the results it gives into a more practical layout for construction.
I'm new to the program, and of course my first two projects using it had completely irregular grids, so that always makes the learning curve more interesting and time consuming.
Like you said manstrom, it does take a good amount of time, and im worried that spending more time modelling and less time getting practical results.
Do you feel that it handles concrete beam torsion well?
RE: Practical Application of RAM Concept
RE: Practical Application of RAM Concept
RE: Practical Application of RAM Concept
Long. top bars
Lat. top bars
Long. bottom bars
Lat. Bottom bars
It makes it much easier to read. I also read results between both the Design Status tab and the Reinforcement tab. They should both show the same thing, sometimes one is easier to read than the other.
You can create new plans under layers/new plan
I layout strips using the span / column strip boundary lines and try to have all of my strips as "manual". You can fairly closely match the intended layout on your drawings.
Make sure and assign a bottom mat under reinforcement. This saves a lot of interpretation.
For beams, I assign user rebar as well.
I have worked at firms that go as far as using user assigned rebar for the entire slab. It's a little overkill for me unless I have a complicated area.
When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.
-R. Buckminster Fuller
RE: Practical Application of RAM Concept
RE: Practical Application of RAM Concept
When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.
-R. Buckminster Fuller
RE: Practical Application of RAM Concept
Safe has been reported as having some serious deflection calculation problems in the versions since it started allowing for cracking an long term effects. Grossly underestimating long term deflections. I do not know if they have been fixed.
Before those versions, it simply reported short term uncracked deflections.
RAM Concept gives you several methods of calculating deflections. Only the most complex one gives realistic deflection results, and then only if the designer has selected to include the Mxy effects in design. There have been some suggestions of unexpected effects in deflections in some cases, and some very weird reinforcement layouts in band beam and slab structures.
RE: Practical Application of RAM Concept
RE: Practical Application of RAM Concept
I actually spoke to a representative over at Bentley and asked him about the Mxy affect that you just mentioned, and he didnt know what i was talking about. Where is this selection made in the program?
RE: Practical Application of RAM Concept
There are basically 4 options to in RAM Concept... as shown below.
RE: Practical Application of RAM Concept
RE: Practical Application of RAM Concept
RE: Practical Application of RAM Concept
RE Mxy, Firstly it must be included in the design. It is not compatibility torsion that can be ignored, it is the non-symmetrical stresses in the concrete that cause it and the effects must be included to satisfy statics and equilibrium.
Adding to the problem, when allowing for cracking in deflections, the torsional stiffness should reduce as well as the flexural stiffness if you are going to reanalyse with cracked properties. To allow for this many designers use a reduced torsional stiffness in RAM and other FEM software.
RE: Practical Application of RAM Concept