Figure area of Rebar based on given % 1

[Bedrock1977]

Is it possible to figure the area of rebar required for a concrete pier or column based on the given percentage (1%) and the size of the concrete member? I know you need the factored load typically, but I just wondered if we could figure it without?

 

[EZBuilding]

No

 

[BridgeSmith]

Depends on whether the area of reinforcing required is governed by a prescribed minimum or by lateral loading. If you have significant lateral loading, the column will have to be designed to have adequate capacity.

I've seen moment-axial interaction curves in concrete texts for common round column configurations, but I don't know the names off the top of my head. There are also numerous programs available, some with free trial periods, that will calculate capacities/design ratios.

 

[JedClampett]

In the old days, CRSI used to publish exactly what HotRod10 is talking about. We still have them. I use them for preliminary sizes all the time. Now they have this Design Guide for Reinforced Concrete Columns.
One of the problems with computer design programs is that there's no way to "eyeball" your first guess. Is a 12 inch column in the ballpark? Or does it need to be 16 inch? those tables were good for that first guess.

 

[MotorCity]

If it was that easy I'd be out of a job

 

[Bedrock1977]

Jed - I do have an older version of the CRSI guide you speak of. It is a very useful tool.

I appreciate everyone's input. Thank you.

 

[IDS]

One of the problems with computer design programs is that there's no way to "eyeball" your first guess. Is a 12 inch column in the ballpark? Or does it need to be 16 inch? those tables were good for that first guess.

Sure there is.

Enter a trial size and reinforcement
Look at results
Adjust to suit applied loads

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/