Re: Building steps

From what I've seen (& read) working in the civil structural field for since 1988, the major cause of reinforced concrete failure is inadequate coverage. Followed by poor quality concrete.

Depending on the "exposure" & environmental conditions, as little as

Epoxy coated rebar is a "new, hot" thing but I'm not convinced that it is "the" solution. Epoxy coating can get damaged during placement, leaving bare steel. :(

I'll put my money on extra cover and good concrete, designed for the local conditions.

Rebar that is fully encased in sound concrete with adequate coverage will last a LONG time.

Too little coverage or poor quality concrete will allow the rebar to begin to rust....the rusting rebar will "disassemble" the rest; quickly at first as it attacks the surface rebar but much more slowly as it progresses to the deeper rebar.

The Huntington Beach, Ca pier (the original one....ca1900) needed to be replaced due to impending structural failure. One of the engineers on the project (evaluation of the old pier) told me that IF the coverage had been adequate, the peir could have been repair and served another 50 years or more. But due to poor coverage the pier had to be demo'd and replaced.

cheers Bob

I never said that corroding rebar in concrete couldn't cause a problem -- I'm simply taking issue with your stand that putting steel into concrete

This is what I wrote in my first response to the OP: "Another reason is that iron has a tendency to rust. When it rusts it expands. This would put the concrete in tension and concrete really doesn't like to be put in tension. In other words it would tend to break up the steps.

Use rocks, brick, or other busted up concrete if you need some filler. "

I used the words tendency, would, tend to - there is nothing there that says in all occasions all steel rusts. I also put the rusting issue in second place in my short list of reasons. You made a massive assumption that I was somehow referring to all situations and you got snarky about it.

Your two comments; "How are they going to get bigger while they're encased in concrete?" and "Oh, for heaven's sake. Haven't you ever heard of rebar?" imply that you equated an engine block dumped in a hole in the ground, with engineered and correctly installed reinforced concrete. I took exception to that.

I appreciate that you think the OP - a guy who wants to toss a considerable quantity of scrap iron into a set of steps as filler - as being so clued in to the correct amount of concrete coverage, and would know how to suspend an engine block to insure that amount of coverage. I have no such illusions.

-- I'm

ideally all rebar should be non magnetic stainless, which never rusts.........

Ideally all people should understand the various properties of 'stainless steel'... Stainless rusts just fine when *not* exposed to air!

I would like a link to that! I was told non magnetic stainless doesnt rust.

What makes this problem worse in florida was the use of beach sand containg salt.

this info courtesy of this old house episode:)

I'll see what I can dig up. This is 'common knowledge' among boat builders, but not others. Problem being that the stainless looks really good on the exposed surfaces, then when you try to remove it, you find a 'ton' of rust on the burried parts. You could also try searching various marine sites too, I'm sure you will find it.

FWIW, I didn't believe it when I was told first about the problem, then managed to see it as I did work on boats.

I think the entire state of Florida contains salt! WHere in Florida are you, I'm frequnently in Tampa, and when to high school in NPR.

No friggin' way. That simply means that virtually any cement highway in NY, NJ, or MI is suspect! They are all full of holes!

(I remember reading a few months ago about the city of NY digging up a location and finding a bunch of bodies: a mafia graveyard, apparently, with little hope of ever identifying those burried in the hole!)

Regardless we all know Jimmy Hoffa is alive and well, living with Elvis in North Dakota.

Oxygen is inseparable from oxidation (rusting). I think it's more likely that moisture was getting into those hidden areas and staying there longer.

You can use stainless bolts and nuts, but there are good practices when doing so, just as everything else in life.

Anti sieze compund

Stainless tends to 'gall' and freeze up. I've had stainless to stainless fastners freeze when tightening, friction welded into one piece so strong that the bolt sheared off but the nut never moved!

Stainless on stainless is used VERY frequently........why else would there be a vast selection of SS bolts & nuts?

galling is a potential problem with SS on SS but the use of proper plating or lubes will help a lot

cheers Bob

PS stop using TV as an uncorroborated source of technical information

SS has a huge tendency to gall......I once screwed together, by hand, a dry SS short nipple (2" pipe) into a fitting. Only a couple turns and the assembly almost seized up on me!

The pipe thread was a pipe rough, I didn't us any tape, lube or dope.....I was just doing a dry fit up.

cheers Bob

........ Oxygen is inseparable from oxidation (rusting).

yup

..... I think it's more likely that moisture was getting into those hidden areas and staying there longer.

yup, again

first of all the term "stainless steel" though popular & widely used is not the "correct" term for the material under discussion

the more correct terminology is "corrosion resistant"

btw all "stainless steels" will rust / corrode under the "right" conditions

another little know fact, so called "non-magnetic", 18-8 stainless steels (typically 300 series) can, when "worked" by certain processes, in fact, exhibit magnetic properties

cheers Bob

rusts...........

I'm late to the party but if they are really concerned about corrosion in the rebar maybe they should look into getting some of the (fairly) new stuff called MMFX rebar. It is five times as corrosion-resistant and up to three times as strong as conventional steel. He could use less steel and it would last longer than just about any other comparable product. Ameristeel is advertising a product called "Z-Bar" that is better (per their claim, not mine) than just plain epoxy coated bars, but I have not been involved with any project that used this material, so I can't say anything one way or the other about it.

Whats the green rebar I saw a while back, was it a coating?

Yep. It's an epoxy coating. It's used in construction where the rebar will be subjected to harsh conditions and rusting is an issue.

I think that is the epoxy (or some sort of plastic) coated stuff. As they lay it out, somebody has to go spot-treat all the spots where they weld it or cut it, lest that provide an entry point for water to get under the protective layer. The spot repairs I see are red, probably to make it quick to check and see that none got missed. A color like green would also make any damaged rusty spots jump out at you.

The green stuff is all I ever see anymore used on bridge or parking garage work around here in salt country. Even see it used on vertical work, like for exposed concrete on buildings.

-- aem sends...