anchor bolt developed length

[Gorpomon]

Hello,

I need to correct some developed length formulas for the manufacture of anchor bolts. I would like to know if those equations have been given in any standards or handbooks. Any help would be appreciated.

 

[Lion06]

I don't know of any developement lengths for anchor rods. The capacities are typically determined using ACI App. D or by "lapping" with rebar.

 

[Gorpomon]

What I'm referring to are the equations for the length of the bar prior to being bent into a u/j shape. In looking at this question it seems developed length also refers to some strength calculation per app. D, is this is the case?

 

[DaveAtkins]

There are so many variables--edge distance, spacing, etc.

You could easily calculate the development length of a bent anchor bolt in an infinite mass of concrete, but the other situations will be more difficult.

DaveAtkins

 

[Gorpomon]

What I mean is we supply anchor bolts, and suspect that one of our formulas in bending the rod during manufacture is wrong,

For instance for an L bend anchor bolt you calculate the length of the short leg, the long leg and then you calculate the length of centerline in the bend and that gives you the length of bar you start off with prior to bending.

This has nothing to do with the strength of installing them or their behavior in concrete.

 

[Bagman2524]

We've used a bond anchorage A of 2.4 SQRT(f'c)/D for J bolts where D is the bar diameter. The load capacity is then just A x L x pi x D. I'm not sure of the source.

 

[DaveAtkins]

Now I understand--and it sounds like your approach is correct. I suspect that when you bend the anchor rod, it yields, and that throws off the length calculations.

DaveAtkins

 

[westheimer1234]

Transmission Poles use "development length" for anchor rods instead of Appendix D.
Anchor Rods usually are around 10 ft for 2.5" Dia
They use drilled piers as foundation.