Drop-in Anchors 1

[Gumpmaster]

What are your thoughts on drop-in anchors?

I require that all concrete anchors have an ICC-ES report on my typical job. I don't know of any drop-in anchors that have an ICC-ES report (please tell me if you know of one). I'm guessing that drop-in anchors aren't as reliable as other anchor types and that's why there aren't any with reports. Contractors seem to love them, but that doesn't mean the should be used.

Do you allow drop-in anchors on your jobs? Why or why not.

 

[AELLC]

Look at the Simpson ones.

I allow them because we are not in a seismic area here, otherwise would prefer epoxy. I like Titens too.

 

[ztengguy]

If it is within the loading charts, I am not against it. Prefer epoxy or mechanical for tension applications.

 

[ameyerrenke]

I use Hilti epoxy anchors 90% the time. They have ICC-ES reports, and are approved for many seismic applications.

An anchor is only as reliable as its installer.. we make sure our crews are trained by Hilti engineers. Proper cleaning of the drilled holes is the key to a good installation, and having the right equipment makes cleaning the holes easy. We usually have the steel erectors install the epoxy anchors, they tend to be much more accurate with their layout than concrete installers w/cast in place.

 

[BadgerPE]

What is a drop-in anchor? Is is an expandable type of anchor? Never heard the term drop-in.

 

[ztengguy]

A drop in anchor is an expandable type anchor. Threaded on the inside for flush application.

 

[wannabeSE]

I don't specify drop-in anchors. If a contractor proposes to use a drop-in for some miscellaneous, non-seismic, low-load, non-critical anchorage, I might consider it.

Powers Fasteners makes a flush screw anchor with internal threads; see

http://www.icc-es.org/reports/pdf_files/ESR-2272.pdf?1395370802.

Also, I have seen Hilti HSL expansion anchors specified when a flush anchor is needed (only comes in metric sizes).

Crakerjack,
Hilti's drop-in anchor is the HDI, See

https://www.us.hilti.com/anchor-systems/flush-anchors/r2457

 

[BadgerPE]

Thanks for the info!

 

[AELLC]

You can't allow drop-in anchors where the concrete is cracked, even hairline. Their capacity then drops to near zilch.

 

[Archie264]

AELLC,

Do you have a reference or technical article saying that? I'm not being argumentative; I would like such a thing handy if I have to argue against their use. Thanks.

 

[AELLC]

Archie
It was per a Simpson Strong-Tie seminar, the speaker expressed it verbally. I will look into it later, right now I am involved with a truss failure conflict.

 

[AELLC]

Archie,

Here are the answers. (This is from my notes and memory - what the speaker at the seminar said.)

Most modern Simpson drop-in bolts are rated by ICC to comply with cracked concrete conditions. They say so in the catalog.

If the bolt is not rated for cracked, then it will have huge decrease in actual capacity, when it is used in cracked concrete.

This Simpson bolt actually performs best in cracked concrete is very expensive, and the builder may get sticker shock. It is the Torq-Cut Self-Undercutting Anchor.

 

[Archie264]

AELLC,

Thank you very much! Especially since I know you are under the gun on the project you mentioned.