Bay Adelaide Centre West Tower (Brookfield, 50s, WZMH)

[CDL.TO]

I walked down the north side of Adelaide this afternoon to have a look for myself and I reached a "Sidewalk Closed" in front of an entrance to the BA construction site with a rope across it. As I waited for a gap in traffic to cross to the south side, a none-too-bright-looking couple walked up to the construction site entrance, lifted the rope over their head, and kept on walking down the north sidewalk right into the construction site. When they reached Bay they clued in to the fact that this was not a through route and just about the same time a construction worker noticed their presence.

Twits.

 

[p5connex]

Yeah, the pics do look great- and it will be great to see how this progresses in comparison to RBC- which seems to be progressing rapidly as well.

I will have to go by and take a look for myself- that which I have seen has mostly been when I am sitting in a car or the streetcar, looking up from King..

p5

 

[Mongo]

From the webcam this morning.

Bill

 

[TrickyRicky]

"Ironically, that's due to the anti-rust coating."

Actually isn't the anti-rust coating rust? What I mean is that they spec pre-oxidized steel. The oxidation layer inhibits further corrosion.

 

[AndreaPalladio]

That's what I thought.

 

[Mongo]

Actually isn't the anti-rust coating rust? What I mean is that they spec pre-oxidized steel. The oxidation layer inhibits further corrosion.

Are you sure about that? The reason that rust (iron oxide) is so damaging is that it is mechanically weak, and flakes off the steel, leaving fresh steel to undergo rusting in turn. I have never heard of "pre-oxidizing" steel; it sounds like it would weaken the steel for no gain.

Aluminium, in contrast, also "rusts", but the aluminium oxide layer is physically tough (and transparent) and protects the aluminium layer underneath.

I do know that many antirust coatings are dull red-orange in colour, and look at first glance like rust.

Do you have a cite for this process? I googled "pre-oxidized steel" and found only research papers on steel oxidation, and information on art pieces that the artists wanted to be rusted in appearance.

Bill

 

[AndreaPalladio]

Is that the whole point of cor-ten steel? The surface rusts, and then no more? Otherwise, all those Richard Serra sculptures and that Shim-Sutcliffe house are in big trouble.

 

[Mongo]

I had never heard of this material; very interesting.

From the Wikipedia article:

Cor-ten was used by St. Louis Car Company to build an order of electric railcars for Illinois Central Railroad in 1971. For uniformity, the next order was built to similar specs, including Cor-ten bodies, by Bombardier in 1979. The use of Cor-ten was seen as a cost-cutting move in comparison with the railcar standard of stainless steel. The durability of Cor-ten railcars did not live up to expectations, and rust holes are appearing in the Illinois Central railcars. Most of these railcars still operate out of Chicago. No other orders of railcars have been made of Cor-ten.

The article also states that it takes several years for the full protective layer to form. According to the NSBA report, "A Primer on Weathering Steel", weathering (Cor-ten) steel requires alternating cycles of wet and dry conditions to form a properly adhering protective layer, so it is suitable for outdoor exposure, but not indoor use.

The reasons that it is used for bridges and the like include (from the report):

• Initial cost savings compared to conventional painted alternatives.
• Minimal indirect costs from traffic delays for major maintenance operations.
• Faster construction resulting from elimination of shop and field painting.
• Good aesthetics since weathering steel bridges eventually achieve an attractive dark brown color that blends well with the environment and improves with age.

The only one that would be of interest in regular building construction would be the first, but the poorer structural and durability qualities probably rule it out.

Bill

 

[interchange42]

Cor-ten has been used for building facades - I've seen it in Chicago. Which building? Must look up...

It was used to create the sculpture at the ACC with the three cones punched through with stars. Same thing for the archway at the Queensway Cineplex.

That's not to say that these pillars at BA are Cor-ten.

42

 

[caltrane74]

I guess we can go to the old addage:

"Nothing lasts forever"

 

[Mongo]

Shouldn't the core be ready for another lift today or tomorrow? They have been going with a six-day cycle recently, and the previous lift was Friday last week.

Bill

 

[AndreaPalladio]

Cor-ten has been used for building facades - I've seen it in Chicago. Which building? Must look up...

It was used to create the sculpture at the ACC with the three cones punched through with stars. Same thing for the archway at the Queensway Cineplex.

That's not to say that these pillars at BA are Cor-ten.

42

Isn't it the US Steel building? The red one?

 

[interchange42]

Ah - it's the U.S. Steel Tower in Pittsburgh that I was thinking of. It's rusty red (and they had to clean up all the rusty red sidewalks surrounding the tower after its oxidization process was complete).

42

 

[AndreaPalladio]

That too, but there is a red tower in Chicago - because of the steel in the facade.

 

[DTGeek]

Shouldn't the core be ready for another lift today or tomorrow? They have been going with a six-day cycle recently, and the previous lift was Friday last week.

It seems like they haven't worked on the core at all for the past week or more, maybe they're waiting for the steel to start catching up.

I remember in a Chicago thread on SSC/SSP the workers on one project refused to work on the core when it got more than 10 storeys ahead of the rest of the building (too many stairs to climb? ).