3D-Structural Concrete Printer

• Subject Area: Construction Engineering and Architecture
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 461499427

The proposed Major Instrumentation facilitates the integration of reinforcement into 3D-printed concrete elements at large scale. The objective is thus the research and production of additively manufactured reinforced concrete structures. The requested Major Instrumentation “3D-printer for reinforced concrete” is to be used, but not exclusively, in the project "Particle-Bed 3D Printing by Selective Cement Paste Intrusion (SPI) - Particle Surface Functionalisation, Particle Synthesis and Integration of WAAM Reinforcement" of the DFG TRR 277 'Additive Manufacturing in Construction'. It is intended to enable the research and large-scale production of concrete components by means of the Selective Paste Intrusion Method (SPI - a process in which aggregates in the particle bed are bound in layers by the local intrusion of cement paste) in combination with the simultaneous layer-by-layer insertion of reinforcement by means of the Wire and Arc Additive Manufacturing Method (WAAM - arc welding). For this purpose, the Major Instrumentation will consist of three main components: an SPI unit for large-scale additive concrete production, a WAAM unit for reinforcement production, and a gantry system spanning over the two aforementioned units (L/W/H = 10/5/5 m³). This enables the combination of the WAAM unit, which is located at the gantry system and thus movable, and the fixed SPI unit located in the installation space. The gantry system will have 5 degrees of freedom at the tool head (multifunctional unit): 3 axes at the gantry as well as a turnable / swivelable tool head. This allows a spatially unlimited production of free-formed elements in the entire installation space. The SPI-unit will be designed in a modular system to provide the greatest possible functionality for material development and later scaling. The complete unit is designed in such a way that, in addition to simultaneous operation, separate operation of the SPI and WAAM units is also possible in order to be able to carry out investigations with the individual materials. Furthermore it is intended to establish the tool head of the gantry system as a multifunctional unit. This allows to couple on the one hand the already described WAAM unit and on the other hand alternative attachments e.g. other welding systems, attachments for concrete extrusion, gripper/connector systems or an additional robot arm. This offers possibilities for the automated insertion of prefabricated reinforcing elements into fresh additively manufactured concrete structures and for the combination of different additive manufacturing processes. In addition, due to the size of the gantry system, collaborative interactions with mobile robots can also be investigated, which considerably expands the range of use of this Major Instrumentation for future applications in the coming years. The Major Instrumentation contributes significantely to the aim of TRR 277 – the large-scale implementation of AM in construction.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: 3D Betondrucker
• Instrumentation Group: 2110 Formen-, Modellherstellung und gießereitechnische Maschinen
• Applicant Institution: Technische Universität München (TUM)
• Leader: Professor Dr.-Ing. Christoph Gehlen