[Ferro List] Iron oxide; was Re: fc tank pics

[Keith B]

Leslie

The "rusting problem" of reinforced concrete is caused by the IRON of 
rebar or mesh.  If/when it rusts, the iron oxide produced has a larger 
volume than the iron it was made from, causing internal pressures which 
act to crack the concrete.  Iron oxide IS rust, so there is no way for 
it to expand and do any damage.

kb

Leslie Moyer wrote:
> ...I wondered if the rusting action wouldn't somehow impair the 
> surface of the stucco, causing it to crack.  In this project, it's added 
> to the Thoroseal, apparently, but I still wonder about cracking due to 
> rust opening up pores in the cement (and, especially so if there were 
> freeze-thaw cycles involved). 
>