Bonding of Concrete without rebar in classified areas

[gadfly56]

Not sure what the codes says, but personally I would want the concrete bonded. Maybe the tank anchor bolts already effectively bond the concrete and tank?

If not, why would the structural engineer care if 20' of copper wire was added to a concrete foundation?

If I were the structural engineer and you couldn't show me a code requirement to add that #4 to my foundation, it wouldn't get added.

 

[steve66]

If I were the structural engineer and you couldn't show me a code requirement to add that #4 to my foundation, it wouldn't get added.

Why, simply why? Do you think the 20' of copper is going to affect the structural integrity of the foundation?? If so, add a connected chuck of concrete off to the side or on the bottom, so it doesn't have any structural purpose, and put the #4 wire in that.

As an electrical engineer, I'm not going to sign off on plans that don't incorporate a basic safety feature I want, code required or not.

I don't claim to know a lot about structural engineering, but if you have a 60" thick piece of concrete foundation the size of a tank (say maybe 20' in diameter), and no rebar, isn't the foundation going to crack into 1000 pieces anyway? Around here, I think it would from the freeze thaw cycles alone.

 

[gadfly56]

Why, simply why? Do you think the 20' of copper is going to affect the structural integrity of the foundation?? If so, add a connected chuck of concrete off to the side or on the bottom, so it doesn't have any structural purpose, and put the #4 wire in that.

As an electrical engineer, I'm not going to sign off on plans that don't incorporate a basic safety feature I want, code required or not.

I don't claim to know a lot about structural engineering, but if you have a 60" thick piece of concrete foundation the size of a tank (say maybe 20' in diameter), and no rebar, isn't the foundation going to crack into 1000 pieces anyway? Around here, I think it would from the freeze thaw cycles alone.

My point was that I'm not going to make my design more expensive for no good reason. If you can convince the client it's needed, fine, but I'm not going to voluntarily waste his money.

 

[kenaslan]

The SE has promised that it will not crack. His problem not mine. Lets not forget with the resistance of the concrete being 60" a difference of potential might exist from the dirt at the bottom, to the top of the slab. Hence step potential. And what about stray voltage? There are also several codes, not just the NEC. API 651 API 2003 API 500 NFPA 77 and others. This can be traced back to 2005 where ALL foundations had to be bonded. Hense, the addition of the 20' Ufer. That way no steel (expensive) is needed, just a chunk of cheep wire and an exothermic bond.

 

[ActionDave]

Not sure what the codes says, but personally I would want the concrete bonded. Maybe the tank anchor bolts already effectively bond the concrete and tank?

If not, why would the structural engineer care if 20' of copper wire was added to a concrete foundation?

First, you've got a vessel sitting on concrete five feet deep. What is 20' of copper gonna do for anybody? I don't think it would make anything safer than having the crew hold hands while playing Bette Middler cds on the night of the third full moon.

Second, the op doesn't want a wire type CCE, he wants a rebar cage if I understand correctly.

 

[ActionDave]

....This can be traced back to 2005 where ALL foundations had to be bonded. Hense, the addition of the 20' Ufer. That way no steel (expensive) is needed, just a chunk of cheep wire and an exothermic bond.

All foundations don't have to be bonded. Even foundations with steel don't have to be bonded. If there's a vapor barrier under the footers or epoxy coated rebar you can't use it as a qualifying electrode.

There is also no requirement to make a CCE if one is not present.

 

[jumper]

That way no steel (expensive) is needed, just a chunk of cheep wire and an exothermic bond.

Excuse me sir, but did you not explicitly tell me that there is no such thing as a wire type CEE.

 

[jumper]

First, you've got a vessel sitting on concrete five feet deep. What is 20' of copper gonna do for anybody? I don't think it would make anything safer than having the crew hold hands while playing Bette Middler cds on the night of the third full moon.

Second, the op doesn't want a wire type CCE, he wants a rebar cage if I understand correctly.

You do not like John Denver or Billy Idol, but you are sitting around listening to Bette Midler?

Wierd.

 

[ActionDave]

You do not like John Denver or Billy Idol, but you are sitting around listening to Bette Midler?

Wierd.

She triggers a certain spiritual reaction in some people.

 

[jumper]

She triggers a certain spiritual reaction in some people.

So does certain illegal drugs.