Mesh Mould: A Robotically Fabricated Structural Stay-in-Place Formwork System

Abstract

Concrete is a highly versatile construction material, not only for the reason that it has excellent properties in terms of structural performance, building physics, availability and price, but also because it can be moulded into virtually any shape regardless of its geometric complexity. However, even though current digital design tools allow to effortlessly design and calculate structures, which are exploiting these properties, this potential remains all too often unrealized. This is due to the fact that geometrically complex concrete structures require expensive, one-of-a kind formwork, which can often not be reused or even recycled. Consequently, the current practice for producing non-standard curvilinear architecture in reinforced concrete is neither ecologically sustainable nor economically feasible for a broader range of architectural typologies. Additive fabrication processes, like 3D printing with concrete, on the other hand, currently struggle with the integration of structural reinforcement, limiting the technique to predominantly non-loadbearing applications. This research addresses both issues and proposes a robotic fabrication process, which unifies concrete formwork and structural reinforcement, and hence potentially reduces formwork waste and construction costs for non-standard reinforced concrete constructions. The development of a fully automated robotic fabrication process involved various research disciplines, including architecture, material science, mechanical engineering, robotics, civil engineering as well as control and vision engineering, and was conducted in three stages. A first conceptual stage investigated the reciprocal relationship of fresh concrete and the spatially extruded polymer meshes, and was followed by a second stage, investigating the translation of the material system from polymer to structurally superior steel meshes. In a final stage, the construction system was adapted and further developed to meet the challenges of 1:1 construction. The results were demonstrated in a final loadbearing structure, the Mesh Mould Wall of the DFAB HOUSE on NEST. In conclusion, the research presented in this thesis laid the foundation for developing this prototypical robotic fabrication system further into a commercial robotic construction system.