Development-Stages of Structurally Optimized Concrete Girders (2023-06)¶

Against the backdrop of the omnipresent climate crisis, the enhancement of resource efficiency within the building sector is more urgent than ever, with concrete as the most widely used construction material being tainted with a high amount of CO2 emissions. In this context, structural optimisation methods are increasingly taken up in the design of mass-reduced concrete structures, provided that the structural performance is preserved. Nevertheless, actual realisation of such girders as well as the evaluation of their load-carrying and stiffness behaviour are underrepresented in comparison to theoretical design finding. Thus, throughout three test series on optimised concrete girders, the authors investigated the potential by varying different parameters. In regard of production methods, 3D concrete printing and conventional casting were looked into. Besides topology, also layout optimisation software tools were sounded out within the formfinding process. Finally, due to the filigree girder dimensions, high demands on the materials were set, leading to the investigation of several concepts regarding reinforcement and concrete material. The experiments proved that concrete girders with less concrete material usage, but an equal or even better performance can be realised. Accompanied by a constant sustainability assessment, a deeper understanding and, thus, a clear statement regarding their contribution to resource efficiency can be made. In a final step, a future test series is proposed, combining the findings of the previously conducted test series.