First step towards fine filament printing

As a first step towards fine filament printing, a concrete optimisation was carried out in order to be able to use existing concrete 3D printing compositions for finer resolution additive manufacturing methods. Among other things, the grading curve was adjusted, especially in the fine-grain range, and the cement content was reduced to achieve a better CO2 balance. As this is a formwork-free construction method, shrinkage cracks can often be observed in the hardened concrete. To counteract this, polymer short fibres were added in different volume contents with fibre lengths of 3 or 6 mm.

The practical tests were carried out on different component geometries. The processing time of a mixture after adding water and the process stability were tested. Several elements were printed next to each other in order to be able to draw conclusions about the reproducibility.  At the same time, the control and operation of the robot could be tested and improved.

In terms of sustainability, test geometries were printed that can be reused as decorative elements.