Georg Brachmann, M.Sc.
Effects of sustained loads on structural response of reinforced concrete constructions
Concrete constructions are often subjected to sustained loads during their service life. In this project of Graduate College 2075 "Modelling the constitutive evolution of building materials and structures with respect to aging", the material behaviour of different types of concrete is to be examined under sustained loads.
Sustained loads specially affect structural behaviour of concrete members, which are subjected to compression. This includes highly stressed columns or walls, plain concrete structures or RC-beams with large compression zone under flexure. Although the concrete technology has been developing steadily over the last few years, the existing studies on long-term behaviour of concrete in the literature date back to around 1960 or earlier and the investigations have been only carried out on normal concrete. Therefore, the long-term behaviour of concrete and the parameters influencing this behaviour should be studied for newly developed concretes (e.g. high performance concrete, ultra-high performance concrete). In addition, influences of steel reinforcement (caused by disturbance of stresses, but also by stress redistribution) and also influences from initial damage (aging) of the test specimens on the structural behaviour of concrete under sustained loads would be considered.
In addition to a literature review, experimental investigations would be carried out on test specimens under sustained loads. Influences of different load levels (depending on the service life of structures) and various time-dependent load scenarios would be studied. Furthermore, parameters such as concrete age at initial loading and different storage conditions of test specimens are to be investigated.
Based on the experimental results, concepts or models are to be developed, which consider the long-term behaviour of different concrete types under sustained loads.
Publications within the framework of the RTG:
Publications in peer-reviewed scientific journals:
G. Brachmann. Bemessungswerte der Betondruckfestigkeit unter Dauerlast. Beton- und Stahlbetonbau 112, Heft 7, S. 437, 2017.
Conference contribution with publication in conference proceedings:
G. Brachmann and M. Empelmann. Bemessungswerte der Betondruckfestigkeit unter Dauerlast. Beiträge zur 5. DAfStb-Jahrestagung mit 58. Forschungskolloquium, Band 2, S. 130-140, Kaiserslautern, 2017.
G. Brachmann and M. Empelmann. Design Compressive Strength Values of Concrete Under Sustained Loads. Tagungsband zum fib Symposium 2017 Maastricht, S. 132 (bzw. Long Paper auf USB-Stick), Maastricht, 2017.