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

摘要

In buildings in constrained and urbanised areas concrete core activation is often used to realize anrnefficient and sustainable cooling and heating system. For concrete core activation usually pipes ofrnpolyethylene (PE) are used for water transportation through concrete slabs in order to cool and heatrnthe slab. These pipes reduce the concrete’s cross section and affect the structural behaviour of thernslab adversely. The new approach, profiled steel pipes are used for water transport as elements ofrnthe concrete core activation and as innovative reinforcement elements as well.rnThis paper presents the concept for using profiled steel pipes as reinforcing elements for structuralrnconcrete. For the use in a first application in floor slabs bond tests concerning the bond behaviourrnbetween pipes and surrounding concrete have been carried out at the Institute and StructuralrnLaboratory of the University of the German Armed Forces Munich, Germany. Based on the testrnresults a theoretical approach based on the German code for structural concrete (DIN 1045-1) hasrnbeen developed. This approach allows the addition of the pipe cross-section and the cross-section ofrnthe conventional reinforcement in consideration of unequal bond behaviour of the pipes andrnreinforcement bars.rnThe paper includes the mentioned bond tests, the theoretical approach to consider the bondrnbehaviour of pipe reinforcement and the first application of the new pipe reinforcement in a largernfloor slab of 50 by 30 m.