Fehlmann, Patrick, Dr.

Research

Fatigue Behavior of Existing Reinforced Concrete Bridges
(Ermüdungsverhalten von bestehenden Stahlbetonbrücken)

All over the world bridges are exposed to increasing traffic loads and volumes. Potential fatigue failures are therefore obviously an issue when surveying the condition of a bridge. Furthermore, today’s engineers are often confronted with an insufficient fatigue resistance according to present design codes on one hand and no indication of fatigue failure on the other. An upcoming failure due to fatigue is therefore uncertain to be detected by routine inspection. This leads to the conclusion that it is necessary to find out more about the evolution of fatigue failure in concrete structures and the ability of methods to detect upcoming failure.
Large-scale tests on a reinforced concrete frame subjected to cyclic loading shall be carried out to investigate the load bearing behavior under service conditions. Emphasis will be placed on the detection of single rebar breaks by non-destructive methods. Different measurement systems will be applied to quantify the strain in concrete and reinforcement of the specimen. Subsequently, the results of the different systems will be compared, which will indicate which system is suited best for field tests. Should the situation arise that, in cooperation with a public owner, an appropriate bridge could be examined and arranged for instruments, the knowledge gained in the laboratory tests shall be verified on a real bridge.

My recent publications

• Fehlmann, P., Wolf, T. und Vogel, T. (2011).
  Versuche zum Ermüdungsverhalten von Stahlbetonbrücken,
  IBK Bericht No. 332, ETH Zürich, 95 p.
• Wolf, T., Fehlmann, P., Vogel, T. (2011).
  First Applications on the Detection of Fatigue Breaks in Bridges with the Magnetic Flux Leakage Method,
  Proceedings of the First Middle East Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures, Dubai, UAE, February 8-10, 2011.
• Fehlmann, P., Vogel, T. (2009).
  Experimental Investigations on the Fatigue Behavior of Concrete Bridges,
  Proceedings of IABSE Symposium 2009, Bangkok, Thailand, September 9-11, 2009, pp. 420-421.
• Fehlmann, P., Vogel, T. (2009).
  Versuche zur Ermüdungsfestigkeit alter Betonstähle,
  Beton- und Stahlbetonbau; 104 (2009), Heft 7, pp. 416-423.
• Fehlmann, P. (2008).
  Fatigue behavior of existing reinforced concrete frame bridges,
  Proceedings of 7th International PhD Symposium in Civil Engineering, Stuttgart, Germany, September 11-13, 2008.

Teaching activities

Other activities

• Member, Organising Committee of YES2012
• Betreuung des ETH-Teams für die 13. Deutsche Betonkanu-Regatta