Louis Schröder, M.Sc.
Interface bond strength of concrete overlays considering aging aspects
For the repair and reinforcement of existing structures, an in-situ concrete overlay can be used. In order to reduce the additional dead weight and due to the high resistance to mechanical and chemical exposures, a high-performance concrete (e.g. ultra-high-strength concrete) can be reasonably used in this case. The technical and economic success of this strengthening measure is determined by the load-bearing capacity of the bonded joint between the existing old and the new concrete overlay. Research on the topic up to date has mainly focused on the short-term static load-bearing capacity of the composite joint. In the real structure, however, such composite joints are subject to service loads and aging influences. Thus, a clear research gap is perceived and can benefit from this project. Focus of interest include the load-bearing capacity after cyclic pre-damage, the fatigue strength before the actual load-bearing capacity is reached, as well as damage effects from sustained loading.
Within the scope of the research project, the aging behavior of the unreinforced composite joint between normal-strength old concrete and a concrete overlay made of a high-performance concrete (e.g. ultra-high-strength concrete) is to be investigated theoretically, numerically and experimentally. The aim is to derive a calculation model for such unreinforced composite joints based on the investigations, which takes into account the above-mentioned aging-specific influencing factors and their damage mechanisms.