Verbund von Beton und Bewehrungsstahl bei hoch-dynamischer Belastung: Entwicklung einer Konfiguration für Push-In-Versuche am Split-Hopkinson-Bar

Against the background of increasing terrorist thread for critical infrastructure, it is necessary to consider the high strain rates related with explosion and impact for the design of structural components. The precondition for this is a realistic characterization of the material behavior. In meso-level the interaction of steel and concrete is described by bond. In order to assess the behavior of structures exposed to high rate loading correctly, even the knowledge of strain rate dependent bond behavior is required. Within the ongoing research project RS1510 at the University of the Bundeswehr München (UniBwM) tests on bond between steel and concrete with a split-hopkinson-bar (SHB) are currently performed in collaboration with the Fraunhofer Institute for High-Speed Dynamics Ernst-Mach Institute (EMI). The results will be used as a basis for the development of a numerical model for the simulation of bond between steel and concrete under high loading rates. After a short survey on bond behavior, the theoretical basis for the testing technology is given and the specific characteristics of the performed push-in tests are explained. The results of the tests show a clear tendency for the rate-dependent increase in bond strength

Profiled steel pipes – innovative reinforcement for floor slabs with concrete core activation

&lt;p&gt;In buildings in constrained and urbanised areas concrete core activation is often used to realize an efficient and sustainable cooling and heating system. For concrete core activation usually pipes of polyethylene (PE) are used for water transportation through concrete slabs in order to cool and heat the slab. These pipes reduce the concrete’s cross section and affect the structural behaviour of the slab adversely. The new approach, profiled steel pipes are used for water transport as elements of the concrete core activation and as innovative reinforcement elements as well.&lt;/p&gt;&lt;p&gt;This paper presents the concept for using profiled steel pipes as reinforcing elements for structural concrete. For the use in a first application in floor slabs bond tests concerning the bond behaviour between pipes and surrounding concrete have been carried out at the Institute and Structural Laboratory of the University of the German Armed Forces Munich, Germany. Based on the test results a theoretical approach based on the German code for structural concrete (DIN 1045-1) has been developed. This approach allows the addition of the pipe cross-section and the cross-section of the conventional reinforcement in consideration of unequal bond behaviour of the pipes and reinforcement bars.&lt;/p&gt;&lt;p&gt;The paper includes the mentioned bond tests, the theoretical approach to consider the bond behaviour of pipe reinforcement and the first application of the new pipe reinforcement in a large floor slab of 50 by 30 m.&lt;/p&gt;</jats:p