Bridge Collapse

[spewey at comcast.net (Spewey)]

Spray-on de-icer is fairly new and European.  Boschung is based in 
Switzerland and has over 50 years of experience in winter maintenance
products and services.
http://www.boschungamerica.com/

This is a 34 page pdf describing the system, first of its kind in US on 
a bridge that big in 1999.
http://www.dot.state.mn.us/metro/maintenance/Anti-icing%20evaluation.pdf

"Various chemicals are available for use in an anti-icing system 
including, but not limited to, magnesium, potassium, and calcium 
chlorides/acetates, glycol, and urea based anti-icing systems.  Mn/DOT 
decided to use potassium acetate in the evaluation of the bridge 
anti-icing system."

It offers the advantage of being less aggressive on soils and much less 
corrosive, and for this reason is preferred for airport runways. It is, 
however, more expensive.
http://en.wikipedia.org/wiki/Potassium_acetate

Scattering salt (sodium chloride) is the age old method and we still use 
it in addition but is ineffective at temps below 15?F.

bzzzt, wrong

Ron Pieper wrote:
> They have far fewer road issues mainly because they don't get the temperature extremes we do,
> especially in the North...like MN...where we NEED deicer, which just kills pavement.  And steel.
> 
> I am very curious to see what the engineer's reports will contain...I imagine we'll read about the
> built-in spray-on deicing system, the pigeon shit, and a curious twist in the structure causing
> bearing failure.
> 
> That's just based on a very quick bit of research...