I'm no expert but I will offer what I think I know and wait for corrections.

1.  Concrete needs reinforcing to be used in buildings.
2.  Steel is used to reinforce concrete.
3.  Steel corrodes, especially in a salty environment.  (From my high school
chemistry recollections, actually a chemical reaction - oxidation/reduction
reaction.  The iron in steel is oxidizing into rust - i.e., iron oxide.)
4.  Corroding steel expands, cracking the surrounding concrete.
5.  Water and some metals like iron, copper, and aluminum are good conductors
electricity.  Many other materials like glass, rubber and (I would guess) concrete
are poor conductors of electricity.

Using this information, I would guess that it is the steel reinforcing that is being

electrified in an attempt to help prevent its oxidation and thereby protect the
concrete.  Does this sound reasonable?


Marilyn Harper wrote:

>      Is this related to a process I heard about that can be used to prevent
>      deterioration of concrete in ocean-front buildings?  The lecture was about
>      spectacular and rapidly deteriorating 50s buildings in Havana, but the same
>      would probably apply to Miami Beach and other such places.  The process had
>      something to do with using an electrical current to change the positive
>      charge on the concrete to negative (or maybe the other way round, I'm not
>      very good at physics!), which apparently inhibits the deterioration due to
>      the salt in the air, or something like that.  The architect I heard seemed
>      to be saying that that (very expensive) process is virtually the only way
>      to save concrete structures near the ocean.
>
>      As you can tell, I didn't understand all of this, but was interested both
>      because of the process and because I didn't know that these buildings
>      essentially couldn't be saved otherwise.
>
>      Anyone know anything about this??
>
>      Marilyn Harper
>      National Register of Historic Places
>      (which is in no way responsible for the content of this message)