concrete filled column
concrete filled column
(OP)
I have a concrete filled column that is weeping and rusting from the inside out. Can calcium in concrete cause the steel to rust from the inside out? If so can I stop it?
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RE: concrete filled column
RE: concrete filled column
RE: concrete filled column
RE: concrete filled column
RE: concrete filled column
RE: concrete filled column
If the tube was sealed both ends with plates after the concrete filling, as civilperson said, no venting for moisture would be available, and that could be your problem.
RE: concrete filled column
I'm struggling to picture a filled tube with internal corrosion bad enough to cause weeping through the wall, unless there is something very wrong.
Is it subject to salt water?
Does it have an internal leaking rainwater downpipe?
Is it outside, in contact with soil?
Is the concrete full of voids due to poor compaction/low slump? (I don't expect an answer for this one?)
RE: concrete filled column
The interface of concrete with steel in a pipe column will corrode from the inside, particularly if the excess concrete moisture was not allowed to vent as noted by others.
If you have perforation of the steel and weeping, then the corrosion is advanced (obviously); however, it is also likely that the concrete is relatively high in chlorides, either inherent to the concrete materials that were used in the mix or through the addition of calcium chloride as an accelerator (ill advised as noted by others).
You might want to create some additional drainage to allow the moisture in the concrete to escape. Check the moisture content and let it get down into the range of 5 to 7 percent by weight. That is pretty much an equilibrium moisture content.
RE: concrete filled column
If the pipe was sealed enough to prevent moisture venting wouldn't this limit the oxygen supply, and therefore also limit the corrosion?
RE: concrete filled column
I think there would be sufficient air in the concrete to facilitate corrosion. It is not easy to expel all the air when placing concrete in a 3 1/2" tube. That said, we only have the OP's opinion that the rusting is from the inside rather than the outside.