Rust and Bridge Collapse

Most recent answer: 11/10/2011

Q:
How does rust effect bridge collapses
- Annonomys (age 12)
IL
A:
Dear Anonymous,
Rust is a reaction product of oxygen interacting with iron forming iron-oxide, the reddish stuff you see on the outside of a steel or iron bar.   Now iron- oxide is not very strong at all, in fact it will simply scale off from an iron structure.  Net result,  the structure becomes weaker and eventually will collapse if the load is heavy enough.  Fortunately, the reaction rate is slow enough that it will take some before this happens.

LeeH

(published on 11/10/2011)