AS3600 PT Design Flat Plate Strip Segment setting and Errors.

[Mkehart]

Hello,

I have recently come back from UK where I did extensive PT design to EC2/TR43 standards, I was very comfortable with the use of RAM to these codes. For 2-way slabs; Full width strip design and Top/Bottom Concrete Stress limits were very simple to design to and if either of these were outside of the limits set by TR43 RAM would give me errors in the status plan to ensure that these sections where amended to the code. Or if i was failing in any other rule set i would get an error with the relevent code. I would also check on crack widths in service rule sets to ensure that they are below the 0.2mm required.

Now that I have returned to Australia I am looking to use RAM Concept to scheme/design PT Slabs to AS3600-2018 and there doesn't seem to be anything the RAM will alert me to if I am failing in the design segments. I have set the segment properties up similar to before, PT segment obviously ticked with Crack width limits set to Code using environment and without direct calculation(tables), and the Code Min rebar to Elevated slab. But when I run it the status plan is always green, even if i remove all the PT i still get 95% OK status. Or if i check my crack width and have an extremely high crack like 2.3mm no errors.

Am i missing something? Is there something I am doing in setting up the model that I need to tick? If that status plan is useless what parameters under Rule sets should I be checking?

Thank you in Advance.

 

[SethGuthrie]

I'm not very familiar with the AS3600-2018 code, but I ran a quick test with the tutorial and checked the manual, see 67.6.13 Section 8.6.3/9.5.2.3 Crack Control for PT Beams and Slabs Without Direct Calculation (Tables).

It looks like the program will either check stress or cracked width based on the "Crack Control Design Type". The limits are pretty large and in most cases the program will keep adding more reinforcement to make it work, so failure is unlikely.

PS, for more attention, try our Forum next time.

https://communities.bentley.com/products/ram-staad/f/ram-staad-forum

 

[Mkehart]

SethGuthrie,

Appreciate the response. So what your saying is that rather than show failures for the certain areas in the status plan, RAM will show required steel in the Top&Bot Status plan to deal with these issues? So as long as I am detailing Rebar to satisfy these Area of steel required then the design is valid?

I posted the same post in the Bentley Forums aswell Here so far no reply.

 

[SethGuthrie]

Yes, at least I think so. You should be able to confirm by checking the designed rebar, or by freezing the program bars as user bars and then reducing the tendons.
Your other post was in the "ideas" channel which is for enhancement requests, so I did not see it. The main "forum" is the best place.