Digitale Fertigung im Betonbau

Concrete Additive Manufacturing in Construction: Integration Based on Component-Related Fabrication Strategies

“…Unlike extrusion, spray-based concrete AM involves the direct addition of compressed air just before the material is applied [11,68]. The process is based on the 100-year-old conventional sprayed concrete technology, except that the material is applied fully automated, with a smaller nozzle distance to the application point (15-20 cm) and at lower pressures (1-2 bar) [64,69]. Analogous to the extrusion process, the material is first delivered to the nozzle by a pumping unit in a dense flow.…”

“…Alternatively, it is possible to print against existing structures (concrete or reinforcing) using different printing angles [76] (see Figure 4). A further overview of spraying-based CoAM can be found in [64,78]. The researchers involved in the development are currently trying to turn the process, alternatively called Robotic Shotcrete Printing (RSP), into a marketable shotcrete technology.…”

“…Usually, for extrusion, very fine-grained material mixes (more like mortar than concrete) are used. This makes the structure susceptible to shrinkage cracking or creep deformation [64]. However, a coarser aggregate will also require a larger nozzle cross-section.…”

“…Binder jetting (BJ): Similar to the SCA process, binder jetting involves the dry mixing of an aggregate and a binder (activator). A resin is selectively applied to bond the A further overview of spraying-based CoAM can be found in [64,78]. The researchers involved in the development are currently trying to turn the process, alternatively called Robotic Shotcrete Printing (RSP), into a marketable shotcrete technology.…”

“…Depending on the particle size, the advantages of particle-bed-based processes are the high-printing resolution and the possibility to produce non-standard shapes, e.g., with overhangs (almost) without restrictions due to the supporting effect of the particle bed [45]. Furthermore, printing time remains independent of the geometric complexity of the component shape so that freeform components can be produced with the same effort [64]. However, the limited component size due to the size of the printer was a major drawback of particle-bed-based processes.…”