Formwork Fabrication Freedom for a Concrete Canoe

Abstract

The pursuit for complex geometries in contemporary architecture is driving innovation towards an unconstrained fabrication freedom for building components. Concrete is a building material with excellent structural and architectural qualities, which has the theoretical capacity of being cast into any shape. However, in practice, concrete is generally limited by the formwork manufacturing industry to solid, planar shapes. The aim of this research is to overcome the fabrication limitations for formwork and, indirectly, for concrete. To achieve this aim, the objective of this research is twofold: a) enable the fabrication of building-scale concrete components through 3D-printed plastic formworks and b) develop computational design and optimisation methods suitable for this fabrication method. The resulting design and construction method takes advantage of the load-bearing capacity of concrete and relies on the fabrication freedom inherited from the 3D-printed formwork, thus making complex topologies and precise details possible for concrete structures. The research method for demonstrating this fabrication process focused on the design to fabrication steps of skelETHon a functional four-meter-long concrete canoe which was designed, built and raced in a regatta on the Rhine river (Figure 1). The main research achievement was the fabrication of the canoe, an optimised truss-like concrete component with members as thin as 15 mm in diameter. Such slender geometric features are difficult to produce in concrete with other known formwork systems.