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So that's how they've overcome abrasion erosion is by
making both parts of the system virtually equal strength.
There's no sense in throwing a high abrasive, resistant
material, if you do industrial floors, the
old technology was to throw on a shake hardener they called it.
The finishers would throw on a real hard rock on the surface
and try and work it into the surface with their blades as
they finish the concrete.
Well that's fine the rocks were abrasion resistant
but you're still burying it in 4,000 PSI mortar
and that's the stuff that's going to--it's the weak link.
It's going to fail first, not the strongest link
and once the weak link fails, then everything else
starts to fail in the system.
So the whole idea is to make a system that doesn't have any
weak links which is what the Corps of Engineer does.
They say dams, waterways, southern Illinois here near
Paducah, they're doing the lock and dam there across the Ohio.
All of that under water concrete is silica fume concrete
[unclear dialogue] any waterways.
This next little segment here on our crime construction site
investigation, part of the handout the two pages that
you all took from up here are talking about this
Hetch Hetchy water system.
We are going to learn a little bit about California
sitting here in eastern Illinois.
Have any of you been to Yosemite, California?
Go out there at least once in your life.
This is a map of the area we are going to be talking about here.
The handouts, this bay area water system.
What they do is they capture the water in the sierras
from the snowmelt to feed all of the populations
of the people on the coast.
California's basically a desert.
Once you get off the mountain range right here on this side
or this side which is Death Valley and Nevada
and there's nothing out there.
It's basically a desert and the only way they can support
all of those people is to collect every bit of
water in the mountains.
I think there are only three rivers in California
that actually flow freely to the ocean.
That's something upstate up here where they still have
a lot of salmon and steelhead and things like that run
so they still keep those open for some reasons.
But otherwise every other river in California is captured for
its water whether it's for irrigation or for people.
This is part of the system here.
The bay area water system operates in Yosemite Valley,
which this is a shot of one of the monuments
in Yosemite valley--it's actually called Half Dome.
A little background on Yosemite:
John Muir, on the right, through his efforts
and without anybody in Congress actually seeing Yosemite,
Congress made it a national park.
The very first or second, no the first national park.
>> male speaker: I think I'm related to him.
>> Mr. Kojundic: Really, one of my heroes.
His grandson is still real active in the Sierra club
and things like that.
>> male speaker: My uncle is somehow
related to him because my last name is Muir too.
>> Mr. Kojundic: Really, wow, wow, wow.
What's that?
>> male speaker: He's on the California court.
>> Mr. Kojundic: I've climbed his mountain
named after him.
Anyway his efforts in law being in Congress and everything
they made this piece of land a national park then
Teddy Roosevelt went out there to show him around.
But Muir was very active in trying to keep this wilderness
wilderness, and in 1913 the bay area people decided
that they needed water, this was a good place for water,
so they created this Hetch Hetchy Dam.
Which Hetch Hetchy is a reservoir.
Hetch Hetchy is actually the title of that paper
that I handed out to you.
It's actually a canyon a couple miles north of this valley we
are looking at here.
They literally dammed up that whole valley
and filled it up with water.
There's one right next to it in Yosemite Valley
that people from all over the world go and visit.
It's a natural park.
It's the place you have to go there at least once in your life
and it will take your breath away as that photograph shows.
But if you go a little north of here the exact same valley
and full of water.
Muir fought so hard to stop this in 1913 that after
they passed the law to dam it up, he died two months later.
Losing that battle, losing the Hetch Hetchy battle.
Anyhow to give you some perspective of what
the valley looks like.
This is El Capitan one of the mountains where people climb it
and I.
This is actually the Petronas Tower superimposed on it.
That's the tallest reinforced building in the world.
It's in Singapore, three quarters of a kilometer high.
Something like that, 120 stories.
Sean Connery and Catherine Zeta-Jones, that one movie with
the cat that walked between up here, that's the building.
That's superimposed on this rock 4,000 feet.
One rock from bottom to top--you stand back
and it's your whole field of vision.
So it's a pretty impressive place.
And you can see on this map that this is the valley
where El Capitan and Half Dome, this is the valley here that
is in place that we showed pictures of.
This is the Hetch Hetchy Valley up here and you can see
it's all blue, it's all a dam that dams up the water.
They need that water though.
They have got 4 million people I think that the water system
in the paper says that they capture.
To give you some idea of the snow.
This is a shot last June, this is a shot last week or two weeks
ago, this is a shot last March, the same shot.
What do they get 20, 30 feet of snow?
It all melted, this was March 19 last year and this is
June 30 last year same shot so snow was what up to here.
They capture all of that.
Nothing goes to the ocean this is what they live off of
and this is what Hetch Hetchy looks like full.
They dammed up and filled it up with water.
Can you imagine this being another 2,000 feet lower?
I don't know how many years of water they have stored
in Hetch Hetchy.
It's a great place to keep water because it's so large.
The down side to it is it's up so high.
It's 8,000 feet up, only so much water and snow lands up here
and can get into here.
Most of the snow is from there on down so what they do is they
literally capture the water in lower reservoirs and pump the
water back up the mountain into Hetch Hetchy.
Because it's such a large reservoirs they have such a big
area there where they can't capture the water so they pump
the water from lower reservoirs that capture it back up into
this major reservoir here.
One of the projects we are going to work on here is actually
a pump station at Cherry Lake.
Cherry Lake is this lake here you can see these little tunnel
shafts this is all pumping water back up hill.
Cherry Lake is here and this little tunnel right here
is our project.
So we are up in the Sierras in the middle of nowhere having to
do a construction job.
You'll go to these places if you're lucky.
The whole system from Hetch Hetchy as you see here is 200
miles long, 60 miles of tunnels, 5 different pump stations,
treatment plants and reservoirs supporting all of these people
all the way up, that's the water system
from that particular reservoir.
The designers out there at the bay area transit system one
have to repair this pump station and you only want to do it
once at least within a couple generations.
So they want a 100 to 200 year design life.
They want to do it once and not have to come back to it
if they can get away with it.
So they go back and find out all this Corps of Engineer stuff
on abrasion erosion and how to make life long concrete
and they find out that silica fume is a good way
to make this type of concrete.
They go to their user's manual and they find on chapter 6 here,
we have a selection of mixed designs.
Starting points instead of, again, we talked about
technology transfer instead of starting over from scratch.
Other people have already done it.
Start off with a good idea and make it your own.
Adjust it, tweak it, and make it what you are going to do.
So we know we need a very high strength concrete.
We go to our tables here and we find that there's a couple high
strength concretes here and they both are high-rise buildings,
but that's okay, we are looking for
the strength in this particular case.
Come up with a mixed design here this is all in metrics
that's because it's FHWA, it has to be in metrics.
The appendix in the book, though,
is all in pounds per cubic foot.
All in English units, our units.
So they use this as a starting point and say we need to make a
mixed design that in order to reach this design life for the
bureau, they wanted about 10,000 PSI.