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Discussion Starter · #1 ·
Hi all,

I'm working on looking at some cost saving measures for a project and was hoping to get some input. There's a few hundred columns we're putting up in a pre engineered metal building, based on the snapshot shown below. The first pour will embed the 24.61" all thread and couplers and the second will cover up to the 16.35" all thread that will be used to fasten the columns. I'm trying to see if we can use black steel for the embedded rod (24.61") since it will be covered in concrete while using a galvanized coupler and galvanized all thread rod for the upper half (the 16.35"). Would this cause any worry for corrosion or mixing metals? I know that the coupler maybe a bit loose with the lower half since it isn't galvanized, but I'm thinking the concrete embeddment will help with that.

The specs call out the rods to be ASTM A36 or A572. Not sure if that helps at all, but figured more info couldn't hurt.

Thoughts or suggestions is greatly appreciated!



511487
 

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Dont ask us, rfi the architect and get your proposal approved.

If your goal is cost saving after the bid the savings should be passed on to the owners.

IMO, NEVER deviate from plans and specs w/o appropriate approvals.

And, no i would not do what you are proposing.
 

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Why would you want to do that? Seems like you will save money and create a cheaper product. BTW ... did you see the news about the commuter train that crashed in mexico city 2 days ago? Want to bet if the contractor tried to save a little money somewhere?

If you want to propose a cost savings, maybe look at using 1-piece allthread and omit the coupler.
 

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no you can't use black steel in place of galvanized. It will rust, expand, and crack/spall the concrete. There's more going on in concrete than just moisture that can rust metal, there's buildup of gases like Chloride that promotes rust. You also should never deviate from plans without a change order.
 

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I've worked on a lot of large government buildings and have never seen galvanized anchor bolts, so I can see why it's being questioned.
 

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Galvanized anchor bolts, all thread and epoxied rebar were all very common in my world.

Not always but they would show up. Seen guys miss the galv call ouy before.
 

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Always use galvanized. Who wouldn't with pt and concrete if you can.

If they are unavailable, in the middle of nowhere, and it won't make much difference, sure. But they are nearly always available.

In the scope of a job, that is the least expensive place to save, and one of the most important.

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Here in the land of fruits and nuts we have to use Galv bolts if they pernitrate PT.
Always use galvanized. Who wouldn't with pt and concrete if you can.

If they are unavailable, in the middle of nowhere, and it won't make much difference, sure. But they are nearly always available.

In the scope of a job, that is the least expensive place to save, and one of the most important.

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Where in that drawing does it show PT (assuming you mean lumber). The OP is talking about a very big structure with hundreds of columns. This jacks up costs a lot. He would be remiss to not question that detail.
 

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You can order them from a qualified supplier.
I'm quite aware that they are easily available, and I've been involved with projects that use them, just not on large buildings. Near my house there was a natural gas compressor station erected. There's several pretty large structures and all the structural steel is HDG, I would imagine the anchor bolts are also galvanized.
 

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Hi all,

I'm working on looking at some cost saving measures for a project and was hoping to get some input.

View attachment 511487
so you are paying for all this and you’re looking at any way to save a few bucks?

Do I have this right? This is your building and you think you can shave a few hundred doll hairs off?

maybe I’m wrong. Still not the best idea to second guess the plans…..what will it cost to get the plans re-worked with engineering to reflect this money saving (hair brained) idea?

As a framer i NEVER imagined trying to change / mod engineering for any reason, unless it was wrong. Then it goes to builder to figure out.
 

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Where in that drawing does it show PT (assuming you mean lumber). The OP is talking about a very big structure with hundreds of columns. This jacks up costs a lot. He would be remiss to not question that detail.
It doesn't show any PT. I was pointing out that that's the only time it's required here.
 

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Where in that drawing does it show PT (assuming you mean lumber). The OP is talking about a very big structure with hundreds of columns. This jacks up costs a lot. He would be remiss to not question that detail.
I was speaking in general terms and adding to the another post.

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Has anyone ever priced the cost of just plain 1-1/2" all thread? I think if you did you'd be asking the same questions as the OP. It's quite common for designers to make expensive mistakes. I have also never seen lengths of all thread used as anchor bolts, that's just wasteful. You have to consider when the building has "hundreds" of columns that a lot of anchor bolts.
 

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I was wondering about that as well. I've seen it, but only as an option when better wasn't available in a timely manner.

Seems like there are better manufactured products for that. But I'm no engineer, so...

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I have also never seen lengths of all thread used as anchor bolts, that's just wasteful.
Why? The detail shows a baseplate with nuts, so no reason to use j-bolts. This detail allows the contractor to buy 20 ft lengths of allthread and cut to length in the field. Somewhere in the specs it probably calls for the cut ends to be treated with cold galvanizing compound.
 

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Discussion Starter · #18 ·
Thanks all for the responses - I agree, I don't think the juice is worth the squeeze for a few thousands savings. Also, what's the difference between an anchor rod and a threaded rod? Are they more or less the same?
 

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Maybe the grade of steel?

Seems like you would have to read the spec book to get an answer.

Maybe the plans call it out...
 

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Discussion Starter · #20 ·
Maybe the grade of steel?

Seems like you would have to read the spec book to get an answer.

Maybe the plans call it out...
No, it was just the way one of the quotes read. I'm assuming its the same, but ill have to call to confirm. Just thought one of yall might've known off hand!
 
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