My friend is building some new concrete steps to his back porch. He
has some old chevy blocks , brake drums and general automotive iron he
wants to get rid of . If these items are clean of fluids is there any
reason we couldnt use them as fill in the steps.
I would not use them because as they corrode they will at first get
bigger (Think about the flakes that come off your drums & rotors).
Then as they corrode further you could be left with a substantial
If you don't want to take the junk to the scrapyard yourself then call
the junk guy. Look in either Craigslist or your local paper usually
in the cars for sale section.
Cinder blocks are cheap and sometimes free, again try craigslist.
On May 17, 8:00 pm, firstname.lastname@example.org (Doug Miller) wrote:
It really surprises me that you have such problems understanding
this. Your personal observation of those funky brown stains on
concrete structures everywhere should indicate that something is
rusting. If you can't see what's rusting, and are keen enough to
realize that rust doesn't just magically appear on concrete, you'll
probably latch on that the rust is coming from inside the concrete.
In a nutshell. Concrete is not waterproof. It wicks up moisture.
The steel doesn't care that it is encased in concrete and will rust in
the presence of the H2O. Concrete sucks in tension - something on the
order of 1/10 its strength in compression. Constant tension on
concrete leads to cracking. Cracking allows in more moisture, and the
cycle continues until the structure falls apart.
Please, DAG. There's a hole in your education.
On May 18, 7:57 am, email@example.com (Doug Miller) wrote:
From the results, some of them obviously were.
Your stance is that you can throw steel into a concrete pour and it
doesn't do anything because, hell, rebar is steel. That's like saying
that you can pour gas anywhere into a car since a car runs on gas.
You know, nonsense.
Like I said, if you want to learn, Google the subject. I'll give you
a head start. This is from Wiki on reinforced concrete:
"Common failure modes of steel reinforced concrete
Reinforced concrete can fail due to inadequate strength, leading to
mechanical failure, or due to a reduction in its durability. Corrosion
and freeze/thaw cycles may damage poorly designed or constructed
reinforced concrete. When rebar corrodes, the oxidation products
(rust) expand and tends to flake, cracking the concrete and unbonding
the rebar from the concrete."
And this is from the Canadian Research Council:
"PREVENTING REBAR CORROSION IN CONCRETE STRUCTURES
by Shiyuan Qian
This article reviews the issue of rebar corrosion, discusses some of
the preventive technologies available, and presents information on
recent studies conducted by NRCs Institute for Research in
The corrosion of reinforcing steel bars is one of the main causes of
deterioration of reinforced concrete structures in North America. It
has become a serious, widespread problem, with repair costs now in the
billions of dollars annually. Whether the corroding rebars are seen
exposed on delaminated bridge decks or
piers, or observed in damaged parking garages, engineers and
contractors are all too familiar with the problem, as are anxious
property owners who call on them to provide solutions."
It's either odd that;
1). these guys are in collusion and making this stuff up
2). you've never noticed it.
My bet is on the second.
The main reason that the OP shouldn't throw the scrap iron in the
steps is because it is wasting money. The second reason is that the
random steel "reinforcing" will eventually cause problems.
I'm taking the liberty of cross posting this to some other groups with
more knowledge on construction than this one. Let's see who weighs in
and which way the verdict goes.
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
2" of coverage is spec'd, harsher conditons 3"+ or more.
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
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.
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
*automatically* poses a corrosion problem that will necessarily destroy the
On May 18, 3:00 pm, firstname.lastname@example.org (Doug Miller) wrote:
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?"
"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 would like a link to that! I was told non magnetic stainless doesnt
What makes this problem worse in florida was the use of beach sand
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! <g> WHere in
Florida are you, I'm frequnently in Tampa, and when to high school in
You can use stainless bolts and nuts, but there are good practices
when doing so, just as everything else in life.
PeterD was saying the stainless rusts when there's no oxygen, and
that's what I was addressing, that you addressed, that I just
addressed. Okay, I'm going to go up on a ladder now, I'm getting
dizzy down here. ;)
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.
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
PS stop using TV as an uncorroborated source of technical information
........ Oxygen is inseparable from oxidation (rusting).
..... I think it's more likely that moisture was getting into those
hidden areas and staying
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"
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
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