In Germany in recent years failures of more than 30-year-old prestressed co
ncrete structures have been observed. In all these cases a quenched and tem
pered steel type, strength class St. 1420/1570 was used. In order to assess
the corrosion risk, i.e. crack initiation and propagation, under depassiva
ting conditions lifetime tests in environments relevant for building practi
ce were carried out using different prestressing steels of this quenched an
d tempered type of material.
From the results it can be concluded that the specific susceptibility of ce
rtain prestressing steels is the determining factor with respect to the occ
urrence of cracks rather than environmental factors.