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>> Ms. Marty McIntyre: That is something that a
pre-caster can give you advice on but it's not always
part of the pre-casters contract to caulk those joints.
That is going to be a maintenance issue so 20 years
down the line, 15 years down the line they
will have to be re-caulked to keep the seal.
Usually you're looking at about a half-inch to three quarters
inch of space in between those panels.
I don't spend a whole lot of time on the connection issues
because the pre-caster is the one who is going to create all
of the connection details.
He's going to actually engineer his own product; he's not going
to engineer the whole building.
He'll need to know the loads, he'll need to know the codes
from the local area and he'll create all of the connections
for his own product.
Some things to keep in mind with fabrication delivery
and installation, just a little bit on that.
First of all, how do you make pre-cast affordable?
How, what's going to happen?
There's two things that I talk about that really make
the biggest difference.
There's other little things that you can do as well but
there's only two things that really, really matter
when you're talking about the costs of pre-cast,
whether it be panels or bridge beams or anything.
First of all, you want to have as much repetition as possible,
and that's because of the manufacturing process.
You want to be able to have multiple pieces all
on that same long line bed.
You want to have the same crane be able to pick them up.
You want to be able to use the same drawings
and engineer each piece so you're not re-engineering
each piece separately.
So a lot of repetition really is going to help
keep the cost down.
The second thing is the piece size.
Do you think pre-cast pieces should be bigger, or smaller?
Bigger, exactly.
You, you want to have them be bigger because bigger
will be less expensive.
You want to have fewer time with the crane,
you want to have the crane pick up fewer pieces of pre-cast.
That being said, you still need to be able to get the pre-cast
to the job and as we've talked about before, concrete is heavy,
so there are going to be some limitations on the size.
You'll also have limitations with just trucking it
to the job site.
In general, a wall panel is going to be limited by
about 12 1/2 feet in one direction.
In the other direction, you'll typically see
about 20 to 30 feet long.
And that's going to be something that they
don't need any special permitting.
It's pretty easy to get it to the job site that way.
If you start getting bigger pieces than that,
you have issues with the pre-caster having to have
cranes in his yard that are big enough to pick up the pieces.
You'll have to have special permitting to get it on the
highway, do there will be issues that will come around with that.
Just as we are talking about the repetition, especially when
you're talking about architectural pre-casts,
they're building all of the formwork.
So you want to be able to use those forms
as many times as possible.
You can build repetition in a lot of different ways,
sometimes you have funny looking pieces because of that.
But in general, also, rectangular pieces of precast
are going to be a lot easier to hang on a building
than pieces like, like this.
Panel size, in general, like we said, bigger is going to be
better, or less expensive.
One of the things you do need to keep in mind
with the panel size, is the pick price.
And that's one of the reasons that you want it to be larger.
Every time a crane picks up a piece of pre-cast
on the job site, and puts it on the building,
the contractor is going to pay a pick price.
And in downtown Chicago right now, that range is in about
the $1500 per piece range, so if you have a 1 x 10 foot
column cover, that's still going to cost you $1500.
It'll cost you the same $1500 if you have a
12-foot by 30-foot piece of wall panel.
So if you start looking at the square footage cost
of putting it on the building, bigger will be less expensive.
There you are, getting to the job site.
It's kind of unusual to have two pieces of pre-cast but because
they have those big punched out windows in this case,
they could do it with the weight of the concrete.
Sometimes too you're going to see some larger pieces.
It is possible to do one of a kind or larger pieces
onto a job site but then there will be special issues that
you need to take into consideration.
In this case they, they're tilting it on it's side.
One of the things that we've seen in this part of the country
is a, a 15-foot-wide double T, which is new.
Most of the double T's that you see around the country are
12 feet wide, so fifteen feet wide, that's a little bit wider,
and they are shipping those also on an angle as well.
In an ideal world, this is what a precast job site would look
like, except that it would be a pre-cast structure in the back
instead of a steel structure.
It's got this nice flat surface, it's got the crane right up
next to the building, you can see the truck with
the pre-cast on it can pull up right next to the crane.
And you pick up the crane and have this nice plumb line
between the crane and the building
and it goes on pretty simply.
So in an ideal world, that's what it would look like.
In the real world, a lot of times, they look more like this.
You know you might have issues with, you've got water
right next to the site or electrical wires, or it's muddy
and the crane is sinking into the mud.
And so there's all sorts of issues that have to be taken
care of before you get that nice crane picking up
the pre-cast off the truck and putting it on the site.
So, real world vs. your ideal world.
Hoisting early a lot of times when you're hoisting concrete,
you do want to either think about starting at the back of
the site and moving forward.
Sometimes you can move around or move
from the inside of the building out.
What, the things that you want to avoid are doubling handling.
You don't want to have to use two cranes to pick
up a piece or pick it up twice.
You want to avoid coming underneath something else with
the pre-cast because you're asking to just ding or chip it.
Pre-cast is actually pretty fragile you wouldn't expect
concrete to be fragile but with the pre-stressing you have to
be very careful about how you're going to pick it up.
You're never going to pick up a long beam from the center of it.
It would just snap right in half.
So you're always going to pick up the beam
from the four corners.
This is a, we talked earlier about Soldier Field,
just to give you an idea of what the *** issues were
at Soldier Field building that bowl.
There they are erecting from the inside.
And you can really see that it was really a tight site, yeah.
>> Male speaker: [unclear dialogue]
>> Ms. McIntyre: They had, where is it?
I think it's right here, they had a piece that everything came
in through this one piece of the, one piece of the stadium.
I think it was there, and they might have disassembled them
before the brought them out.
It's been about three years since I sat through
a presentation on this, yeah?
>> Male speaker: [unclear dialogue]
>> Ms. McIntyre: Usually, in this part
of the country, the pre-cast is usually part of the pre-casters
contract and so they don't usually use helicopters
or anything like that.
Now I did have a pre-caster up in Milwaukee,
have you ever been up there and seen the riverwalk that
they've built up there that kind of comes out on the river?
That uses all double T's, and that was actually an FOB.
They just took the pre-cast to the site and dropped it at the
riverbank and then they had barge that came in
and they barged it out to the site and placed it in.
But the pre-caster did't want anything to do with it.
He just didn't feel like he knew enough about barges and water
to get that *** so that was a specialty erector,
but I've never heard of anybody using helicopters for it.
We talked about this earlier but I always like to just mention
it again that PCI certification is your good housekeeping seal
of approval on your pre-cast and it is something that
you know it's always looked for when you're talking about
who's going to actually going to do the pre-cast on a job.