epoxy dowel embedments?

[dirtsqueezer]

I am working on a project where the plans specify epoxy dowel installation according to ICBO ER-5193 (also allows for Simpson SET). My question is, is there a standard minimum embedment depth specified for a certain size bar that one can use on a jobsite (that's what the plans imply)? I think this contractor is looking for a catch-all for his beam-to-slab, curb-to-slab, slab-to-wall, ect. connections.

PS. None of these embedments, or dowels for that matter, are on the plans themselves.

 

[Rjeffery]

Refer the Question back to the designer, make him (gender neutral) take the liability.

 

[JedClampett]

I would agree with Rjeffery that contacting the designer is the safest bet. But if some contractor had a gun to my head, I would make him fully develop the bar in tension. For ICBO Report ER-5193, I would require that the bond or concrete strength exceeds the allowable tension in Table 10. For 4000 psi concrete, it looks as if you're always in the highest embedment region.
Is there a reason you're not using the RE500 epoxy (ICBO Report ER-1682)? It looks like you get a lot more bang for your buck.

 

[shin25]

I also agree with Rjeffery. Ask the design engineer give you the number. One word of advise, be careful about the long term performance of the epoxy under sustained tension load (specially for the fast set type).

 

[dirtsqueezer]

Is RE500 red? I think I've seen that used on site, but never before. Not for the regular epoxy, though.

Yes, I was wondering about the long-term effect, especially after hearing about ceiling tiles in a tunnel falling on NPR, I believe in Chicago. Looks like, however, given the wide use of 'quick set' epoxy, that there'll be a lot of building concerns with long-term strength. This stuff's used all the time.

The problem with asking the engineer is that it takes a few days to get an RFI actually to the jobsite. With all the small (and large) epoxy jobs we have, it would just be rediculous to get RFIs for each of these. Maybe I'll just ask for a blanket statement for the life of the project.

Thanks for the good posts.

 

[GeoPaveTraffic]

Just a side comment/question.

In the area of the midwest where I work, dowels are generally smooth bars designed for shear transfer. The only time that epoxy is used with them is to ensure complete contact between the bar and the concrete, i.e. to fill the oversize portion of the drilled hole.

We use the term reinformcment if there is a tensile load component.

Now for the quesiton, how does this compare to other areas of the country?

 

[dirtsqueezer]

We use the term 'dowel' loosely for reinforcement, usually in the horizontal direction. Your meaning I assume is for slab joints connected by smooth bar, usually greased. I'm in Washington State.

 

[jike]

Dowels can refer to either smooth or deformed bars. If it is called off as x/x" dia. dowel then it is normally smooth, if called off as #x dowel then it is deformed.

 

[facca]

We install 15m rebar on highway bridges usually 6'' to 1' deep and are then required to pull test 5% to a certain strength.

 

[strguy11]

It appears from your post that the designer has already specified that the embed lengh meet the test reports.

 

[Zambo]

facca,

what diameter are your 15m rebar? I think 6" (152mm) is too short an embedment. What load do you use for the tension test?

I would have thought it would be better to use the manufacturer's literature to select the hole depth and diameter. Then use a hollow jack to carry out a couple of off-site tension tests on bars installed into a block of the same grade concrete. Once the tets have been carried out then the operation should proceed under supervision.

 

[DRC1]

The depth and installation method depend on the epxoy producer. Most anchors have data to devolp intallation criteria. If it is permenant, you may need to submitt for approvalto the engineer. Hilti is more expensive than a lot of other brands, but they give you all the data you need fordeterming layout & installation.

 

[msquared48]

The depth really depends on the shear cone you need to develop to resist the pullout. This depth can vary, not only due to the f'c, but any edge conditions that may intersect the cone, thus reducing the full shear cone capacity.

You could easily develop standard tables for full cones for various f'c values for various types of bars with no problem. The edge conditions would be the special designs.

Mike McCann
McCann Engineering