Hilti HY-20 into hollow CMU IBC approval

[blackmaddog]

I can't find an ICC report for Hilti HY-20 for use in hollow CMU block. Does anyone know if it is acceptable to use this anchor for a 2006 IBC structural application? If so, do you use the Hilti capacity data?

Does anyone know of any other epoxy anchors that can be used in hollow CMU block?

 

[vandede427]

are you sure you understand how an epoxied anchor works?

 

[JLNJ]

Shallow embedment sleeve anchors are the only ones I use in hollow CMU. I still have a hard time trusting them though.

 

[kslee1000]

Whenever use manufactured commercial products, you are the one been held responsible for. If this is the first time encounter with that product, as mentioned above, both understanding and data verification are very important steps, unless it is sheltered by reputable organizations. For this case, I think you are on your own.

 

[blackmaddog]

Vand - I am not sure what you are getting at but I assume you are not familiar with the product. It is designed to be used on hollow masonry construction.

http://www.us.hilti.com/data/techli...choring_Systems/4.2.8_HIT_HY_20_(278-287).pdf

JLNJ - I am reluctant to use an expansion type anchor because it is in a corrosive environment and they can't be relied on. If I can determine the capacity of a through bolt, it would work in this application.

kslee - That is why we have ICC-ES reports to independently test products per code requirements. However, I can't find a epoxy based product for anchoring to hollow CMU that has an ICC report.

 

[kslee1000]

Black:

If I remember correctly, one of the manuf produced a manu full of mistakes. I guess you aware as well. That's the trap we have keep in mind.

 

[PUEngineer]

My guess is that you are going to be hardpressed to find an ICC report on an epoxy anchor into hollow masonry construction. ICC reports for the IBC 2006 are few just for the typical conditions. In seminars with Hilti and others, I don't think I've heard of any manufacterer persuing such approvals for their epoxies in those conditions.

To answer your other question, Read Head anchoring has a similar product and I would imagine Powers does also.

 

[JAE]

Here is a link to Hilti's website where they list ICC approval documents

Hilti HY20 documents

 

[PUEngineer]

I didn't see one for the HY-20 in the particular case in question...maybe one of the other manufacterers has a report.

 

[PUEngineer]

BTW... apparently I should have someone check my posts for spelling errors.

 

[BRGENG]

JAE link leads you the way to the report (

http://www.us.hilti.com/data/techlib/docs/approvals-listings-reports/icbo/ESR2659.pdf

).

You can always call Hilti if you don't want to look for it and they will send you the requested information ASAP.

 

[blackmaddog]

BRGENG,

The report only covers unreinforced masonry (ie brick) with a minimum thickness of 13". It does not reference hollow CMU block.

I did call Hilti and have not received any response from their engineers.

 

[kslee1000]

black:

What is your need for install thru bolts on hollow CMU. I guess the face cell couldn't take much of load, combined with high uncertainties, does the application really makes sense?

 

[blackmaddog]

kslee,

Your point is good and worth considering. Obviously connecting to un-grouted CMU will only support relatively small loads.

In my case, other options are more complicated, expensive, and less desirable. The Hilti technical guide indicates that a 1/2" HY 20 anchor into hollow concrete block has an allowable shear of 1230 lbs (with a safety factor of 4). My connection has 2 anchors to resist a maximum load of 500 lbs. So, I have a safety factor of 5 below the Hilti allowable load. Also, the anchors are through a ledger channel which will distribute load (ie redundancy).

On a side note, there are many times that non-structural components need to attach to un-grouted CMU. Back to my original question, do we need a ICC report for Masonry anchorages that are governed by the IBC?

 

[kslee1000]

I think that's really a judgement call. With report, your research/documentation is much simpler. Without, you might have to get to the bottom of the method that was used by Hilti to come up with that number, than verify it by any method you see fit (regarding load distribution, block/bond strength...etc). Often, it is not a simple task, especially when the data was obtained through testing (per ASTM,...?).

 

[kslee1000]

Also, suggest to provide both side with similar set-ups (angle-angle, channel-channel), and provide adequate length to utilize the ribs of the blocks to resist the load.

 

[priya15]

The way I have been handling epoxy anchors is as follows:

I use Hilti tables for allowable deisgn. The shear capacity values, I use just the way they are. But tension capapcity values, I divide by 6. Do not use the ultimate values. There is a factor of safety of 4 in-built in the allowable capacity values and an additional 6 makes it very safe. I have used these in IBC2003 and IBC2006 code jurisdictions. I have no problems so far and my company always liked this kind of safe approach to expansion anchors.

My suggestion is use expansion anchors with a high (ridiculous) safety factor of 10 in tension and you are good. Problems arise only when something fails. we as engineers always want to avoid problems. Again, this is how I have been doing and it worked.

 

[blackmaddog]

I received a phone call from the Hilti regional engineer in Seattle and he indicated that ICC has not addressed anchors into hollow CMU and that there is not any reason that they can't be used for building code applications. It is up to the engineer and the building official for items that do not have ICC reports.

Prior to his call, I had already taken the approach described by priya above. I think SF=10 is excessive, but if you are well below the manufacturers reported allowables (which have a high safety factor) and the anchors are installed correctly (special inspection), I think that it is a good safe design.

Thanks to everyone for your responses.

 

[JLNJ]

Ultimate/4/6 = Ultimate / 24.

Safety factor of 24, not 10. For something with a 1000# ultimate you use an allowable of 24#? Must be some small loads!