Investigations to Improve the Carbon Footprint of Thin Walled Concrete Structures by 3D Printing Prefabricated Elements (2023-06)¶

Additive Manufacturing - AM processes are gaining acceptance in many industries due to their unique design freedom. New design approaches such as topology optimization (TO) and structural optimization using lattice structures are possible. Pilot projects in the housing industry show that possible applications, in this case concrete AM, are also conceivable in the context of construction processes. This paper deals with the production of thin-walled concrete structures and shows material-related reduction potentials compared to conventional prefabricated concrete components. To this end, various extrudable high-performance mortars, some with fiber admixtures, have been developed and an appropriate standardised test specimen has been designed. On the basis of numerous material tests, it was possible to derive significant statements about the application limits of the developed materials, which are fundamental for the design of topo-logically optimised cross-sections of concrete components. The aim of this research project in the field of concrete AM is to produce segmentally built flexural beams and to investigate their load-bearing capacity. The test beams consist of several segments, each with a concrete formulation and a 3D design adapted to its calculated stresses. The segments themselves are manufactured without any classical reinforcement elements and are joined together after the manufacturing process with the application of prestressing with or without subsequent bonding. The segments can also be CO2 cured in an accelerated process prior to prestressing to further improve the material properties and to further reduce the environmental footprint through CO2 storage.