Four Masters students from Bartlett School of Architecture - Francesca Camilleri, Nadia Doukhi, Alvaro Lopez Rodriguez and Roman Strukov - have developed a new method for 3D printing large-scale, self-supporting concrete structures. With their project Fossilised, the team, known as Amalgamma, combined two existing concrete 3D printing methods - the extrusion printing method and the powder printing method - to create a form of supported extrusion that allows for "more volumetric" concrete structures.
"The supported extrusion method has therefore presented the opportunity to design forms that are more varied and more volumetric, as opposed to the very straight vertical forms so far achieved in 3D concrete practice," says Amalgamma.
"The process involves the extrusion of ready mixed concrete using an industrial robotic arm programmed to follow a linear fabrication tool path," explains Amalgamma. "The concrete is pumped to the robot and deposited through a customized tool head that extrudes to a one-centimeter resolution. This is done at multiple layers, each time depositing granular support material around the extruded concrete.
"In order to enhance the results a binder was incorporated into the extrusion process which was used to harden certain parts of the granular support to produce a multi material piece. The finalized 3D printing process therefore combines a dual material nozzle of concrete and binder which connects to an industrial robot and print both materials in the same routine.
"Fossilized aims to challenge standardized concrete fabrication techniques by questioning the nature of the fabricated piece," Amalgamma describes in their portfolio. "Although 3D printing a while structure from start to finish may not be possible... it could be possible to print, for example, a floor-wall-ceiling assembly or stair-floor-wall assembly as one whole architectural chunk... These chunks could be assembled on-site as done with traditional prefabrication techniques, however their tectonic qualities would be completely different."
Working under their tutors - Manuel Jimenez Garcia, Gilles Retsin, Vicente Soler - the students now aim to integrate multiple materials into the process and combining the granular support with the printed concrete.