Avoiding Rust and removing water in structural steel HSS

[Max Tension]

I have a condition on a project where a large hss structural steel Post has some water pooling below grade. It has a solid steel end cap and is bolted to a concrete girder. an electrical access hand hole was never sealed up and so there has been water inside it for the past three years, I didn’t feel any standing water but would like to have a recommendation for something to absorb moisture to avoid more rust.

One thought was some sort of dessicant but was also considering just putting some dry cement powder inside. Any thoughts on this or reason not to do that would be appreciated.

 

[HTURKAK]

The following para. from the book HOLLOW SECTIONS IN STRUCTURAL APPLICATIONS ( By JAAP WARDENIER )

Many investigations, summarized by Tissier (1978), have been conducted to assess the likelihood of internal corrosion. These investigations, carried out in various countries, show that internal corrosion does not occur in sealed hollow sections.
Even in hollow sections which are not perfectly sealed, internal corrosion is limited. If there is concern about condensation in an imperfectly sealed hollow section, a drainage hole can be made at a point where water can drain by gravity.





Use it up, wear it out;
Make it do, or do without.

NEW ENGLAND MAXIM

 

[Max Tension]

I appreciate your response HTURKAK, it is unfortunate that this steel post was not properly sealed with a cover plate in the first place as was our expectation. I plant to have it sealed up ASAP but am hesitant to do so with moisture trapped inside. Perhaps I shouldn't be too concerned with it but I do not want the rust to continue to corrode the interior of the post at ground level where the greatest loads exist. I do wish I could get a weep hole into it for drainage but since the hollow pipe extends below grade on the interior, that will not work.

That post supports has a 39 kip (mostly compression) load, which grows to a 67 kip load (with significant moment) in a max wind/snow/ice load scenario so I don't want this post to be compromised at the base over time.

 

[Eng16080]

If the issue is removing the existing water, isn't this a simple matter of using a shop vac to get it out? After that, let it dry for a few days before sealing it shut.

 

[Max Tension]

Thanks for the thought @Eng16080 I was thinking the same initially, with a stepped down hose to reach inside, if there was standing water I would have done that but since it was just moist mud/rust I just used a dry rag to absorb what I could. I think the cement powder may have been a good option but I think it will be dry enough. Unfortunately it's been raining off and on, so having it dry for a few says wasn't an easy option.

 

[EdStainless]

Before you close it up toss in a package of VPCI.
And if you really want to a few packs of clay based desiccant wouldn't hurt also.
I have seen closed systems that have water in them and it cannot be sealed.
They added a corrosion inhibiting oil and it coated the surface as water levels changed.
This kept the metal at the waterline protected and it lasted a very long time.

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P.E. Metallurgy, consulting work welcomed