Corten Steel 2

[msquared48]

Been doing some research on Corten Steel and it's shortcomings. specifically the lessened life span due to corrosion from an environment that is wet with salt laden air, as in the Pacific Northwest. Looking for more opinions here.

Anyone have any professional experience they can share on the matter and if any feasible fixes were used and effective? Consider painting, cathodic protection with zincs, ongoing recommended maintenance procedures?

The structures would be bridges, light poles, and monopole transmission towers.

Thanks for any additional insight here.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[dik]

It's good in it's place... it gets its corrosion resistance by forming a relatively tight oxide layer, not like loose flakey rust... Initial corrosion is faster and if this oxide layer is abraided away, it can corrode faster than plain normal steel.

Another problem is the use of it on the exterior where the rust layer can drip onto clean stone or concrete. It stains and unless the detail is such to contain the 'drips' it can be unsightly if exposed. I've seen some steel sculpture work done on concrete pedestals and the steel has rusted and stained the concrete in an unsightly manner.

I've used it occasionally over the last 40 or so years... and, in the right place, it is good.

Dik

 

[kylesito]

I would think that using any kind of coating system or CP wouldn't really make sense as you might as well do these things with normal steel. However, some of the architects and clients I have worked with wanted to use the corten steel for a certain aesthetic...they wanted the rust look. In my mind, if there isn't a desire for this aesthetic then it's not worth the effort. The short falls dik mentioned are valid but if you want to look then it's a good solution.

PE, SE
Eastern United States

"If a builder builds a house for someone, and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death!"
~Code of Hammurabi

 

[SkiisAndBikes]

I have used corten in a lot of sculptures that I have designed. The choice was primarily driven by the artists desired outcome. We have had staining problems on the concrete beneath the sculptures. Over a 10 to 15 year period, they are all performing well with no outward signs of corrision related problems.

There are many bridges in my area made from corten steel. Primarily pedestrian and light vehicle bridges within park systems. They seem to perform well in my area. My area does have significant snowfall during winter but no slat laden air. As these bridges are not normally located on the throughfare, they don't see much deicing salt.

 

[bridgebuster]

Mike,

Dik makes a good point about staining concrete. On bridges we usually put drip bars on the bottom flange of stringers & girders 5' from the abutment to prevent staining. Also, some state DOT's paint the first five feet as well.

I attached the FHWA guidelines for use of weathering steel (just in case you don't have a copy).

 

[dik]

Thanks for the post BB...

Dik

 

[bridgebuster]

no problem Dik.

 

[acocorten]

Hello ALL of the forum, here in Brazil we currently make Windturbine towers ( or poles maybe this is the correct naming) in galvanized corten steel and epoxy coating,the usual name for this material combination is "triplex" the estimated life in marine environment is 50 years... i really dont see any corrosion in this towers some have 10 years sitting at beach side.

Regards to ALL

 

[msquared48]

I got wind of a report by ASCE back in the mid 80's, I believe, that documented the recent propensity of Corten to start rusting again, after it had stopped, due to decreased pollution in the local area. Apparently, the air pollution, in sufficient quantity, did something chemically to halt the rusting process. Seems odd, but, hey, I'm open to documented evidence, even if it's from the ASCE.

One of the pitfalls of cleaning up the environment I guess...

Anyone have a copy they can post or link me too, or heard the same thing? Tried online, but haven't come across anything yet. I do not have an ASCE membership ... yet.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[bridgebuster]

Mike - try AISC Steel Solutions Center; they give free advice.