Cliff wrote:
On Mon, 26 Sep 2005 14:26:49 -0400, Kirk Gordon
wrote:

If the same salts are disolved in less water, the salt concentration
goes up, and freezing temps are reduced to even more extreme values -
WAY below 32F.

Actually, you may recall that below a certain temp they stop
salting the roads. No matter how much salt they might use it
would cause no melting.


Calcium Chloride is exothermic. It releases heat as it disolves
in water. Crushing the snow under car tires momentarily melts
the snow allowing the CaCl to get started. If it is too cold,
perhaps the snow doesn't melt when crushed.

ALso, some places apply hot brine to problem spots.

AFAIK in NE Ohio they appy somethign to the roads down to
-20 F, which is about as cold as it gets there.

--

FF