Concrete Interaction Diagrams

[Perception]

Hello everyone,

I have a question about the range of values interaction diagrams are produced for. From what I can tell most sources only produce interaction diagrams from gamma = 0.6 to gamma = 0.9, where, gamma*h = center - center distance between longitudinal rebar. Does any one know the reasoning to this? I know how to make the diagrams by hand, but I was just curious why such a low range of diagrams are typically available from most sources.

Thanks

 

[jayrod12]

Venturing a guess here, but since the best place for your reinforcement is as far away from the compression zone as possible, you'd never really need them closer together than 0.6h. Not to mention once they start to get that close together they start to be ineffective as bending reinforcement.

But that's just my best guess.

 

[hokie66]

Less than 0.6 is a small column, smaller than about 300 mm. Greater than 0.9 is a large column, say larger than 1000 mm. Most of our columns are somewhere between. Maybe the decision has been that it is a waste of paper to print diagrams which are rarely used.

 

[dik]

Hokie... that was the explanation we were given...