Long-term behavior of bonded anchors

Bonded anchors reached high market shares, due to their high performance. In consequence of two tragic accidents, currently the long-term resistance of bonded anchors is regarded critically, even if it is now known, that serious deficiencies in the construction have been the cause. Currently different research groups try to establish new procedures, to be able to safely predict the behavior over 50 years within an acceptable period of time. In this paper the current approval procedures and public research projects are presented. The bonded anchors available on the market differ strongly in the chemical structure. Previous forecast models do not consider this aspect. Differences in the reaction mechanism are focused and consequences for the long-term behavior are identified. To establish more reliable models, the reflection of the molecular level is required. Misinterpretations as in both accidents will be avoided, if multidisciplinary teams of engineers material scientists and chemists collaborate.