| Abstract: | Prestressing steels can be exposed in prestressed concrete structures in construction stage (ungrouted duct) to environmental conditions causing formation and growth of hydrogen induced cracks with brittle fracture of the steel. The risk of this hydrogen induced stress corrosion cracking can be minimized by appropriate treatment, but there is a requirement for construction to approve only prestressing steel having no enhanced susceptibility to stress corrosion cracking. The paper describes the historical development of the different test methods proposed in the past and gives an overview on the general requirements for a suitable test method to assess the hydrogen‐induced stress corrosion susceptibility of prestressing steels. Since 1982, based on investigations on construction sites and transfer of the results into laboratory tests, a test method is available enabling realistic estimation of suitable application possibilities of prestressing steels. This so called DIBt‐test is approved to distinguish between prestressing steels susceptible to hydrogen induced stress corrosion cracking and those suitable and therefore approvable steels at practical environmental conditions. Furthermore the test enables estimation of corrosion risk for newly developed prestressing steels with higher strength. |
