|
NATIONAL
Traffic Guru
New Accounting for Salt
With
so much worry about crumbling bridges and roads, why aren’t we
giving ourselves a shake -- and asking whether the money saved
by using deicing salt is really worth it? The alternatives are
very expensive, but we need to know if the fight against
slippery pavement is leading to a higher risk of catastrophic
collapses.
Salt is the
cheapest, most effective way to keep transport infrastructure
clear of ice, within a certain temperature range (it doesn’t
work in very cold situations). Yet it’s clear that the same
stuff that’s keeping our vehicles on the road is also damaging
both. Do we need to start rustproofing our bridges?
For years,
drivers were not fazed by concrete flaking from an overpass or
by the sight of steel reinforcing rods, exposed and oxidizing.
But stories of chunks falling from ageing elevated expressways
are now viewed with some alarm -- especially after seeing images
of collapsed bridges in Quebec and Minnesota.
Corrosion
happens -- we’ve known for decades that the metal bars embedded
inside concrete structures are vulnerable, and that salt is a
leading culprit.
This year
brought the final report of the 2006 bridge collapse in Laval,
just north of Montreal. The main faults were ascribed to poorPLEASE
SEE "SALT", PAGE 2B
Past Articles Published in The National Post
|
