Stereotomic Green Vault: clay 3D printing applied to stereotomy

This paper aims to describe an experiment conducted to test clay 3D printing applied to the architectural field, in particular to the realization of complex ashlars for the construction of vaulted spaces. Additive Manufacturing (AM) is progressively spreading in the building sector, in particular in the fields of social housing, infrastructures and installations. Moreover, some research has led to the realization of totally compressed and discretized vaulted structures, as the Vulcan Pavilion (Studio LCD), the DE: Stress Pavilion (Ball State University) or the Striatus Bridge (Zaha Hadid Architects and ETH of Zurich). These two mentioned experiments are part of the scientific field to which the present experience belongs. As a matter of fact, this research is focused on the use of AM for the realization of stereotomic vaulted spaces. The research path was based on the will to innovate the traditional constructive system of fictile tubules, which is widely diffused in Italian Old Towns; we specifically refer to the so called “caroselli”, that are terracotta elements that were not inserted one into another, but that were placed radially following the direction of the vault and were kept together by mortar A Wasp 40100 Clay printer was used to fabricate a new typology of ashlar. It had to be hollow like caroselli – in order to guarantee lightness – but it also had to have a complex shape. This was meant to obtain the reciprocal interlocking of blocks – and then a better stability – but also an interesting geometric pattern. The principal inspiration has come from the study of the Truchet ashlars. A prototype of a portion of a barrel vault 1,2 m wide has been realized. It was composed of three rows of interlocking ashlars, joined without the use of mortar. Moreover, a resistance tests has been done on the model. During this first phase of fabrication some reflections about advantages and disadvantages of clay 3D printing have been conducted and a possible future development of this research and its innovative application to the architectural field has been hypothesized.