Help, calcium/efflorescence buildup in conduit

Status
Not open for further replies.

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Wow. That is way beyond anything that I have ever seen. I agree that this doesn't look like calcium build-up.
Could it be some sort of electrochemical reaction? Has anyone analyzed that white stuff?

Usually calcium buildup comes from heating and cooling hard tap water, but to create the deposits in that picture would require a whole lot of water. Where is all that water coming from? It wouldn't be rainwater, either, unless... Wait a minute, could that be gypsum? I'll bet you somewhere else there is a lot of dissolving drywall.
 

big john

Senior Member
Location
Portland, ME
Holy frijoles!

The first picture, I can relate to. But I've never seen a pipe completely filled like the second picture. If that is solid throughout the pipe, then unless you can get Rotorooter to bore through it, you might end up writing off the conduit.

Pouring anything in will only act on the face of that deposit, and it'd take forever to try and disolve it that way.

When I spoke of experiencing this problem, I've seen it in hydroelectric dams. If mere water pressure through concrete were capable of filling conduits like this, all our pipes would be full. I think you've got something else going on here.

Possibly a bad batch of concrete used to pour the duct bank?

-John
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
Jeez, that looks like that foam scene out of the movie Willy Wonka.

If that stuff is solid all the way through the conduit, I don't anything that could get through it.
 

squirm

Member
Hello everyone and thank you for the responses. Just to follow up on, I do not know if this is solid throughout the conduit, or just around the stub-ups. My HOPE is, it's just around the stub ups. I cannot verify if it is calicium build up at this point, I plan on getting some analysis performed to verify this. Our current thought is, it's just a very bad case of efflorescence. Around this area is very high hydrostatic pressure, so that's what we're basing it on.

We can't say for certain if it's bad concrete, although this has happened at more than on facility, and the inspection reports have not indicated anything problematic with the concrete pours.

Since this is happenend at two different remote sites, industrial leaking acids or similar would seem remote. In fact, the pictures posted are from a facilty that is in a very rural area.

I agree, perhaps Ghostbusters has paid a visit. :grin:

Regarding the Rotor-roter should that bridge be crossed if we get to it, wouldn't their process damage the conduit? My thinking is, if this is impossible to chemically decompose, then the last ditch effort would be Rotor-roter.

Here are some more picutres.

attachment.php

attachment.php
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Hello everyone and thank you for the responses. Just to follow up on, I do not know if this is solid throughout the conduit, or just around the stub-ups. My HOPE is, it's just around the stub ups. I cannot verify if it is calicium build up at this point, I plan on getting some analysis performed to verify this. Our current thought is, it's just a very bad case of efflorescence. Around this area is very high hydrostatic pressure, so that's what we're basing it on.
I read a little on line about efflorescence; a fluffy texture/structure seems to be a characteristic of efflorescence, and this stuff looks more like dried out slurry to me. Is there gypsum wallboard (sheetrock drywall) anywhere nearby that could be taking on water and sluicing off?
 

squirm

Member
I don't think that's calcium... It would need to be heated to form that kind of solid or it would need more than a few years to build up to that degree. What's the consistency of that stuff? What kind of soil is around the concrete that the pipe is in? Is there any industry in the area whose runoff would explain it or which might be leaking acidic liquids or gases that could create this in a reaction with the concrete itself? It just seems like too much buildup to be happening naturally.

I would have to pull the soil analysis report. Unfortunately I don't have that in front of me. However these facilities are located adjacent to major rivers and each facility is seperated 20 miles from each other.
 

squirm

Member
I read a little on line about efflorescence; a fluffy texture/structure seems to be a characteristic of efflorescence, and this stuff looks more like dried out slurry to me. Is there gypsum wallboard (sheetrock drywall) anywhere nearby that could be taking on water and sluicing off?


Hello, no, there is no drywall located near or around this.
 
Status
Not open for further replies.
Top