John Kane wrote:
>
> It also may depend on how old the bridge was. If it was built 40
> years ago there was a lot about stressed concrete that people did not
> know about especially interactions with salt!.

The salt leeches through the concrete and gets into the reinforcing rods.
Eventually the rebars start to rust, and when they rust they expand causing
spalling.... concrete flaking off. However, I don't think this collapse
was a result of that sort of process. It appeared to be more a matter of
the steel structure giving way under the weight of the concrete deck.


> Also if I remember correctly the US Federal Gov't funded construction
> of the Interstates but not the maintaince so if the states were cash-
> strapped then mantaince might sufferer. BTW was not that bridge
> linking two states? Just ideal for a nice bureaucratic war over which
> state pays the bills

It is likely the same system that we have here in Canada. Various
jurisdictions are responsible for road maintenance for their own roads, but
each jurisdiction filters the money down in a network of grant systems. For
instance, here in Ontario, my town has its own roads to maintain, the
regional municipality has its roads to maintain and the province is
responsible for the highways. The province gets some money from the federal
government. The regional municipality gets money from the province and
shuffles some of it down to the town. There is a vast bureaucracy that
exists to pass the money back and forth and a lot of politicking going on
to see who gets how much.