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 evironment 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.
RAM Concept will add program reinforcement to meet the code crack control requirements. In most cases, RAM Concept should complete the design without a design code failure related to crack control.
When the "Without Direct Calculation(tables)" option is used, the program enforces a maximum stress limit on the steel reinforcement. This is an indirect way to control crack width and may not be related to a specific crack width limit.
I am not expecting the high crack width (2.3 mm) that you report. Is that crack width associated with the Service Design Rule Set or another designer? Can you please share your model with the large crack width using our Secure File Upload so we can take a closer look?
Hey Karl,
Appreciate the response I think I understand the difference now. From what you are saying is that RAM will counteract the failures by allocating additional Rebar requirements. So as long as I have an all green status plan and have satisfied all my required top and bottom area of steel then my design will be valid.
The 2.3mm crack was just an extreme example of if I took a PT slab design and pulled out all the tendons in both directions I would still have all my status as OK even with huge crack widths. But then my required rebar in that zone would have been huge to negate the crack.So I wont waste your time on looking through it.
This is why I was worried since when i used RAM in the UK it would give you failures regularity if your crack width was too high or your top & Bottom Conc stresses were outside of the TR43 requirements. So looks like just a different way of operating RAM between the codes.
Let me know if you think I am on the right track
Cheers,
Mike