Ann: Investor Presentation, page-68

That is an interesting paper, thanks PMF. I was of the belief that the decrease in permeability led to a reduction in corrosion rates. However, as the paper points out, the conductivity of the nanotubes negates the "modest decrease in permeability" therefore leading to an increase in corrosion. They do also go on to say "the increased tendency to corrosion needs further investigation." As the paper is three years old, presumably more study has been done on this.
I am also interested to know if the same doubts are duplicated for graphene reinforced concrete.