To Cut or not to Cut (vertical reinf)

[ironmon]

I'm working on a foundation modification to fit a new piece of equipment. It's a bending unit for a caster in a steel mill. About 6 ft of the pedestal base will be removed and 3 ft of it will be recast. I have advised for selective demolition that will keep the perimeter "vertical" bars (#6@12) intact and to be re-cast in the new pedestal. Our sales safe want to cut all the bars and dowel in with adhesive/epoxy dowels, which will save construction time and costs.

Is it worth it to keep the original bars continuous?

Is doweling equvilent from an engineering point of view?

Thanks for you thoughts.

Ironmon.

 

[ChipB]

Ironmon,

You are not asking for the impossible, but you are asking for the most expensive.

Yes, in most situations, you can dowel and epoxy bars in. You have to embed the bars enough to develop the reinforcing if there is a moment. I wouldn't use just any type of epoxy. Specify Hilti RE500 (or approved equal).

Chip

 

[csd72]

If this is vibrating machinery, I would imagine the original bars would be better under fatigue loading than epoxy bars.Check with the manufacturer.

Also with all those existing bars in the pedestal it wont be as easy as they think to drill a hole. It certainly will not be in the corners (the existing bars are already there!)

Other option is to retain approx 12" of bar and use a suitable mechanical splice.

 

[hokie66]

Why cut off bars that you know are reliably anchored and install more bars that depend highly on workmanship and require a lot of inspection? Sounds to me as if your sales staff should stick to selling. In work like this, the concrete work is such a small component compared to the cost of the machinery, I think any such consideration is false economy and foolish.

 

[Tomfh]

Specify Hilti RE500 (or approved equal)

500 is good stuff. The problem I find is that most builders will just use 150 unless you make sure.

 

[ironmon]

Thanks, everyone
My thoughts exactly hokie66, I made the same points, and I'm sticking to my guns!
If the client demands epoxy dowels, then I will consider the RE500 or others, but i'd rather use that as a backup position.
Thanks Again.

Ironmon

 

[csd72]

I just noted that it will be in a steel mill.

Epoxies perform very poorly under heat, if this is anywhere near any heat then epoxies will be inappropriate.

Even if it is not how do you know that they arent going to build something in the future.

 

[ironmon]

Another good point csd72, which makes keeping the original bars intact, a better approach.

thanks