Additive Manufacturing of Concrete: Challenges and opportunities

A modern incipient trend is being witnessed in the construction industry wherein concrete is pumped which flows through a nozzle connected to a robotic arm in successive layers in order to develop structural load bearing members generally referred as "Additive manufacturing of Concrete(AMOC)" or 3D Printing of Concrete (3DPC). Numerous challenges are being faced by the construction industry for implementation of Additive manufacturing of concrete to a large scale due to the scarcity of information available w.r.t this technology. This technology has opened up new opportunities which requires intensive research to be carried out to ensure that concrete gets pumped through the pipe(pumpability), extrudes through the nozzle (extrudability), retains its shape once this concrete is extruded from the nozzle(buildability). In addition to this, concrete has to be strong enough to withstand loads induced by upper layers without any deformations (shape retentivity). If the challenges related to pumpability, extrudability, buildability and shape retentivity can be addressed in a better manner, this technology of 3D concrete printing can be utilized to construct houses/building components at a rapid rate and bring down the overall construction costs exponentially with optimal usage and minimal wastage of resources. This paper addresses the various challenges which are commonly encountered in the Additive manufacturing of Concrete (AMOC) summarizing the potential solutions to it discussing some of the case studies of projects which have used this technology.