Pop-up concrete constructions: forming fabric reinforced concrete sheets

New technologies and fabrication tools urge us to explore new materials and their potential for integration in architectural construction. One such material, Concrete Canvas, is explored in this paper for its hybrid characteristics that blend fabric and thin-shell tectonics. The potential of Concrete Canvas lies in its ability to modify itself from a flexible fabric that when activated with water becomes a rigid concrete structure. Combined with a digitally controlled workflow of on-site cutting and an iterative material feedback loop, the process can serve as a radical alternative to current concrete formwork fabrication techniques. This paper outlines a prototypical design process that combines a phase-changing material, physical computer simulations, robotic fabrication and scanning technologies on a feedback loop between the digital and the physical that allow for customized, free-form, on-site concrete structures to pop-up without the need of a complex formwork. In this process the architect sets the various parameters based on fabrication techniques and material properties and adjusts them iteratively in the physical and digital model during the ‘popping-up’ process until a balance between material properties, technical requirements and aesthetics is reached, exploring new potentials on digital fabrication processes. The paper outlines the proposed workflow including iterative experiments with robotic cutting of flat patterns, their ‘popping-up’ into 3D concrete shells, and material phase transitions during its forming process. The established feedback loop consisting of geometry scanning, parametric perforation pattern control, computational analysis and simulation, and robotic fabrication is described in detail. The paper concludes by exploring the potential of this process to enable a dialogue between digital architecture and the process of materialization and discusses the implications of this approach in relation to architectural design and fabrication workflow