In article ,
Ray wrote:

The gap, no more that 1/4 inch, is between a concrete sidewalk and
vertical metal walls surrounding steel metal doors that cover stairs to
the basement. The concern is water getting in the gap, then freezing in
the cold New Jersey winters, expanding and damaging the concrete.

I couldn't find any caulk in Home Depot that specified both concrete and
metal. That may be just because the situation isn't that common, and one
of the caulks may very will do the job without having to be replaced
every couple of years.

Thanks,

Ray

I'm agreeing with the silicone suggestions.

Do keep in mind, however, that not all silicone is created equal.

In tests, the strength can vary by a factor of more than TWO! (I wish I
still had the links..I believe I started somewhere on Gluguru.com's
site. Either way, it's one helluva site for adhesive information. They
even have an adhesive that will stick to Karl Rove *G*)

I am not affiliated with Gluguru, btw.

Stick to GE. They make most of it in many grades for just about all
brand names.
'Silicon II' they keep to themselves, so it seems....it's by far the
best of them all. (Aquarium builders insist on that one, I'm told.)