Development of a shotcrete 3D-printing (SC3DP) technology for additive manufacturing of reinforced freeform concrete structures

Abstract

In this paper, a novel Additive Manufacturing (AM) technique for robot-based fabrication of large-scale freeform reinforced concrete elements is presented. The AM technology, called Shotcrete 3D Printing (SC3DP), is based on an automated shotcreteing process and offers the ability to integrate structural reinforcement in both principal directions and enables printing of horizontal cantilevers onto vertical surfaces. Moreover, the SC3DP technique effectively addresses the problem of cold joints that is inherent to other 3D printing techniques. However, as controlling the process parameters of the SC3DP technique is significantly more complex than it is for conventional 3D concrete printing processes, several closed-loop online control routines were developed and integrated. The resulting gain of control for this adaptive fabrication process is demonstrated through a case study for the production of a complexes reinforced concrete component. Moreover, its conceptual implications are discussed and an outlook for future work is given.