Digital Concrete Processing (2018-11)¶

With burgeoning interest in digital fabrication for construction scale processes, new challenges have been opened in the realm of concrete processing, as characterizing and controlling the “very” early age strength during the setting of cementitious materials takes on new importance. While there are some universal processing requirements to all digital concrete processes such as 1) extrusion, 2) slipforming, and 3) controlled casting, there are differences that alter processing windows and even fundamental requirements. This work is based upon the experience of the Digital Concrete Processing collaborative project at ETH Zurich and centers on defining guidelines in terms of varying processing requirements for these three classes of processes as they relate to digital fabrication. From this paper, it can be seen that in general, extrusion processes place the highest demands on the material in the pumping and placement phases, while slipforming places the highest demands in the building phase, with the smallest processing window. Controlled casting (“Digital Casting”), on the other hand, seems to offer the largest processing windows. Some initial guidelines are defined, including the importance of considering downstream material impacts in processing concrete, the need for simplification of material requirements to ensure successful concrete processing, with concomitant admixture usage reduction.