Tip:
Highlight text to annotate it
X
(Mr. Kolb). Let's go into the building.
As you can see, the construction slow-down has hit this plant.
Typically, we have 225 laborers in our plant.
Right now we're down to about 50, and that is because of the
construction industry slow-down.
(male speaker). [unclear audio].
(Mr. Kolb). We have, I think it's
19 or 20 acres.
(female speaker). [unclear audio].
(Mr. Kolb). The question is, do I think
the demand for employees will increase.
Yes, in the construction industry.
(female speaker). Anytime soon?
[laughter].
(Mr. Kolb). Sorry folks, sorry folks.
We just hired a construction management graduate
from ISU this week.
I do think it will turn around, it has to come around.
And unfortunately, all the monies that have been
going out right now for our infrastructure, that we had
through what they called the stimulus program,
has gone out for asphalt.
Bridges will catch up with that, but the thing
that triggers everything is housing.
When they start building housing, that means there's
money out there for people to start buying that stuff.
When that happens, the little stores open up,
everything else opens up.
(Dr. Toosi). Are they [unclear audio].
(Mr. Kolb). Yes, those are concrete posts,
instead of using steel beams.
So they're matching the same paint on those things, and
they'll slide right down those pieces.
Ok, test number one.
What's this, what kind?
(female speaker). [unclear audio].
(Mr. Kolb). This is what's known as
epoxy-coated rebar.
This is standard rebar, standard carbon steel, nothing else.
They dip this in epoxy coating, and the epoxy coating is
supposed to prevent rusting of the steel and popping
and deterioration of the steel.
You either use epoxy coating or galvanized.
(Dr. Wahby). How does this epoxy coating
affect the bonding to concrete?
(Mr. Kolb). There have been many studies
on that, and they're continually going on.
The question is, how is the bonding affected
by the epoxy coating?
Some people say that the bond is to the epoxy coating
versus bonding to the raw steel that has all the fins
on it and everything else.
That has fins, but it's coated with a plastic.
So what does the concrete bond to?
That's a question that people, such as your professor,
are evaluating because right now, folks, we have bridges,
we have brought beams back into our plant that are
over 50 years old, bridge beams that have used rebar
and stuff like that.
We break them open and the steel is just like this,
not epoxy coated, it's raw steel and it's not rusted
and it's not deteriorated.
So a lot of your universities are studying, is this the way
to go, is that the way to go, hot-dipped galvanized.
(female speaker). What's the difference between
galvanized and [unclear audio]?
(Mr. Kolb). This is, remember,
this is a coating.
They take the steel that's like that, they take it and
bring it up in sheets and then dip it in a vat and it's
chemically reactive to like a, what's in galvanizing?
It's a magnetic charge, an electronic, electrical magnetic
charge that pulls the coating right to the steel.
This is just like paint.
(Dr. Wahby). How are the new types or
relatively new types of steel that doesn't rust and the
mix itself, when they prepare it, not coating or galvanizing,
but the mix itself, the mixture of the steel itself
doesn't rust inside, outside?
(Mr. Kolb). Typically, what we're seeing
some of that, we're going to be doing a parking deck in about a
month, and they are specifying stainless steel connectors.
Now, stainless steel connectors go about $8 a piece for a
little piece of steel that's about like that.
Very expensive, but stainless steel does not rust.
Stainless steel doesn't have any reaction back into the concrete.
When this stuff starts rusting, it actually causes the concrete
to split around it, it actually causes cracking of the concrete
because it's a chemical reaction with whatever is in
the concrete and the steel.
That's why they put epoxy coating or galvanizing on it.
Little building over there, hope to God we never have to use it,
it's a tornado shelter.
And we laugh, but you know what, folks?
Every summer you look out over that field there and you can
see funnel clouds dancing across the field.
(Dr. Toosi). I thought that's a
torture chamber.
(Mr. Kolb). No, it's not a torture chamber.
[laughter].
It's a tornado shelter.
If we just look around the corner over here.
Remember, this is the precast operation on this side.
It has it's own batch plant over there, own aggregates,
own sand piles, everything else that goes into concrete
is self-sustained right on that, that service is
this side of the plant.
So, you see that big hopper that's over there?
That's another batch plant that handles the prestress part.
Typically, the prestress part is inspected by
the state of Illinois.
So, they have all sorts of different requirements,
prestress versus precast.
Let's go inside and get you out of the cold.
(female speaker). I have a question.
So those green epoxy-coated rebars are like, when we have
construction on the highway, are those the, that
stick out of the ground?
(Mr. Kolb). Yeah, when you see like in
bridge construction or poured in place, you'll see
these green bars coming out of it, that's exactly
what you're seeing.
When you see it, when they cut out a section of the
highway and you see all the bars laying flat,
that's what you're seeing.
(female speaker). So when are the other ones
used, the galvanized ones.
(Mr. Kolb). The question is, when are
galvanized used versus epoxy-coated?
We use galvanized because when you use epoxy coating,
if you're handling it and you pick it up and you tear that
epoxy coating, you have to physically come back and
repaint it with another epoxy coating.
So you imagine, I'm paying someone X amount of dollars
an hour to sit here with a little brush painting
all the cracks that's on that epoxy coating.
Galvanized, that doesn't happen.
It's all a matter of money.
Galvanized is more expensive than epoxy coating, but you can
handle it and it's a lot more forgiving.
(female speaker). But it's used for
the same thing?
(Mr. Kolb). Same thing.
(female speaker). What are these green things?
(Mr. Kolb). These things here are a product
that's called step wall.
It's a retaining wall system.
It's a patented system, and we are the licensees.
There are two licensees in the United States,
we're one of them.
It's a bin wall retaining wall here if you're trying
to hold back dirt.
What you do is you step those samples up and fill the insides
up with what they call porous granular fill, which does
nothing more than let the water run right out of it.
This will keep your embankment from going like this.
It's called a retaining wall.
These are the forms for that retaining wall.
(Dr. Toosi). Pretty much a large version
of landscaping.
(Mr. Kolb). Yes, yes.
Remember I showed you those flat panels out there,
the ones that looked real smooth?
This is a high-end plywood, probably three quarters of
an inch thick, but what happens is there's always seams when
you put plywood together.
This is an epoxy coating that goes, that levels out all the
seams, and you can pour this and it will give you
a flat, smooth finish.
(Dr. Toosi). A kind of polyurethane on it,
is that right?
(Mr. Kolb). Yeah, well, this is actually
an epoxy coating.
You can feel it, how smooth it is.
This is a standard form liner.
Remember the ones that we saw where
they're painting them out there?
This is what I told you we use a high-end form liner.
This stuff as you see it right here costs about
$50 a square foot.
And what you do is you affix this, as you can see it's
affixed to plywood, and then it's got rabbit joints on the
plywood that put it together like this and holds it tight,
and then we caulk the joints if we see any seams,
and then you pour your concrete on this and then
you strip the concrete away.
Typically, when we make sound walls with two sides on them,
we make them inside a vertical form.
What you're looking at here is this piece here.
Don't be afraid.
As you can see, these are those wall panels that you saw
from outside with form liner on both sides.
What they do then is they close this form up to
whatever thickness you want.
They pour the concrete from the top down and then,
on the sides of the forms, in this track and
this track up here, are vibrators.