Learning from historical structures under compression for concrete 3D printing construction

This paper reviews and extracts lessons from historic buildings, whose stability relies mainly on compression to resist gravity loads, that can inform the construction of affordable housing and shelters using 3D printed concrete without reinforcement and formwork. The first part consists of a literature survey of historic constructions with systems relying on compression considering four vectors of analysis: (1) form; (2) structural principle; (3) materials; and (4) construction process. The survey starts by identifying forms whose structural principle may be adequate for 3D printing of concrete applications. Then, historic structures displaying similar forms are analyzed in terms of structural behavior, the types of materials employed, and the construction process used to obtain foundations, walls, and roofs. A series of historically inspired shapes for printing is thus obtained from this survey. To address the printability of the structures identified after the survey, the second part of the paper provides a brief description of existing processes for construction scale printing considering material aspects, such as fresh state behavior, and printing system configurations. Addressing the fresh state properties of concrete is crucial as it determines whether the structure fails during printing. Finally, a set of strategies including potential toolpaths and intermediate states are defined to print the identified forms, considering issues concerning material requirements and printing process.