Fabio Gramazio

Complex concrete structures

Over the course of the 20th century, architectural construction has gone through intense innovation in its material, engineering and design, radically transforming the way buildings were and are conceived. Technological and industrial advances enabled and challenged architects, engineers and constructors to build increasingly complex architectural structures from concrete. Computer-aided design and manufacturing (CAD/CAM) techniques have, more recently, rejuvenated and increased the possibilities of realizing ever more complex geometries. Reinforced concrete is often chosen for such structures as almost any shape can be achieved when placed into a formwork. However, most complex forms generated with these digital design tools bear little relation to the default modes of production used in concrete construction today. A large gap has emerged between the possibilities offered by the digital technology in architectural design and the reality of the building industry, where actually no efficient solutions exist for the production of complex concrete structures. This paper presents construction methods that unfold their full potential by linking digital design, additive fabrication and material properties and hence allow accommodating the construction of complex concrete structures. The emphasis is set on the on-going research project Smart Dynamic Casting (SDC) where advanced material design and robotic fabrication are interconnected in the design and fabrication process of complex concrete structures. The proposed fabrication process is belonging to an emerging architectural phenomenon defined first as Digital Materiality by Gramazio & Kohler (2008) or more recently as Material Ecologies by Neri Oxman? 1. An overview is given that combine existing casting techniques with digital fabrication for the fabrication of complex concrete structures.The focus is set on Smart Dynamic Casting a technique that combines digital fabrication with slipforming and building material science.An overview of the experimental set up and procedure is given.Experimental prototype results are described.

Building tensile structures with flying machines

This paper presents the building of lightweight tensile structures with quadrocopters. The construction elements (such as ropes, cables, and wires) in this kind of structure are subject to tension forces. This paper identifies the basic building elements (nodes, links) required for the construction of tensile structures, and translates them into meaningful trajectories for quadrocopters. The use of a library of building elements is suggested. Hybrid force-position control strategies based on admittance control are exploited. Prototypical tensile structures are built by quadrocopters to validate the proposed approach. An accompanying video shows the building process.

Mobile robotic fabrication on construction sites: DimRob

In this paper, viable applications for mobile robotic units on construction sites are explored. While identifying potential areas for in-situ fabrication in the construction sector, the intention is also to build upon innovative man-machine interaction paradigms to deal with the imprecision and tolerances often faced on construction sites. By combining the precision of the machine with the innate cognitive human skills, a simple but effective mobile fabrication system is tested for the building of algorithmically designed structures that would not be possible through conventional manual means. It is believed that this new approach to man-machine collaboration, aimed at a deeper integration of human ability with the strengths of digitally controlled machines, will result in advances in the construction sector, thus opening up new design and application fields for architects and planners.

Mobile Robotic Brickwork

This paper describes the implementation of a discrete in situ construction process using a location-aware mobile robot. An undulating dry brick wall is semi-autonomously fabricated in a laboratory environment set up to mimic a construction site. On the basis of this experiment, the following generic functionalities of the mobile robot and its developed software for mobile in situ robotic construction are presented: (1) its localization capabilities using solely on-board sensor equipment and computing, (2) its capability to assemble building components accurately in space, including the ability to align the structure with existing components on site, and (3) the adaptability of computational models to dimensional tolerances as well as to process-related uncertainties during construction. As such, this research advances additive non-standard fabrication technology and fosters new forms of flexible, adaptable and robust building strategies for the final assembly of building components directly on construction sites. While this paper highlights the challenges of the current state of research and experimentation, it also provides an outlook to the implications for future robotic construction and the new possibilities the proposed approaches open up: the high-accuracy fabrication of large-scale building structures outside of structured factory settings, which could radically expand the application space of automated building construction in architecture.

A Case Study of a Collaborative Digital Workflow in the Design and Production of Formwork for ‘Non-Standard’ Concrete Structures:

This paper presents an overview of ongoing research from within the Tailorcrete research project into the development of CAD tools for the design and realization of ‘non-standard’ concrete structures. The focus is on concrete formwork, a significant factor affecting cost, logistics and aesthetics. With a process spanning a broad range of expertise, collaboration through an effective digital workflow is vital to the successful execution of such structures. As a concept for this workflow, a working model of a Design System is described and its development discussed. This focuses on three aspects: (1) the identification of key Use-Cases; (2) the definition of Formwork Systems; and (3) the definition of communication between software elements to provide relevant means of collaboration for expert users. An implementation as a package of software prototypes is also briefly presented. This includes a Base Framework, tools targeting Use-Cases and components relating to specific formwork systems.

Wiggled Brick Bond

The wiggled brick bond is a generalized running bond which can be locally compressed. It was introduced to apply a bond onto two intersecting double curved bands. The wiggled bond is capable of shrinking and stretching with a constant gap between the bricks. Furthermore, the wiggled bond provides us with a generic crossing between two brick walls at an arbitrary angle. In this paper the mathematical techniques behind this bond are examined in detail.

Topology Optimization and Robotic Fabrication of Advanced Timber Space-Frame Structures

This paper presents a novel method for integrated topology optimization and fabrication of advanced timber space-frame structures. The method, developed in research collaboration between ETH Zurich, Aarhus School of Architecture and Israel Institute of Technology, entails the coupling of truss-based topology optimization with digital procedures for rationalization and robotic assembly of bespoke timber members, through a procedural, cross-application workflow. Through this, a direct chaining of optimization and robotic fabrication is established, in which optimization data is driving subsequent processes solving timber joint intersections, robotically controlling member prefabrication, and spatial robotic assembly of the optimized timber structures. The implication of this concept is studied through pilot fabrication and load-testing of a full scale prototype structure.

Mobile robotic fabrication at 1:1 scale: the In situ Fabricator

This paper presents the concept of an In situ Fabricator, a mobile robot intended for on-site manufacturing, assembly and digital fabrication. We present an overview of a prototype system, its capabilities, and highlight the importance of high-performance control, estimation and planning algorithms for achieving desired construction goals. Next, we detail on two architectural application scenarios: first, building a full-size undulating brick wall, which required a number of repositioning and autonomous localisation manoeuvres. Second, the mesh mould concrete process, which shows that an In situ Fabricator in combination with an innovative digital fabrication tool can be used to enable completely novel building technologies. Subsequently, important limitations of our approach are discussed. Based on that, we identify the need for a new type of robotic actuator, which facilitates the design of novel full-scale construction robots. We provide brief insight into the development of this actuator and conclude the paper with an outlook on the next-generation In situ Fabricator, which is currently under development.

Building a Bridge with Flying Robots

The research presented here investigates techniques and tools for design and fabrication of tensile structures with flying robots. Tensile aggregations are described as a concatenation of nodes and links. Computational tools provide the designer of such a structure with the necessary aid to simulate, sequence and evaluate a design before fabrication. Using a prototypical suspension footbridge as an example, this paper describes the techniques and challenges for implementing the construction method on a full-scale, loadbearing, architectural artefact. Firstly, a series of tensile links is fabricated at defined lengths between two distant support structures to build the primary elements of the bridge. Secondly, cooperating flying robots brace the assembly by braiding the primary elements to one another. And finally, the structure is stabilized through the fabrication of additional connections by robots flying around existing elements within the porous structure.

Material ecology

The world of design has been dominated since the Industrial Revolution by the rigors of manufacturing and mass production. Assembly lines have dictated aworldmade of standard parts framing the imagination of designers and builders who have been taught to think about their design objects and systems in terms of assemblies of parts with distinct functions. The assumption that parts are made of single material and fulfill predetermined specific functions is deeply rooted in design and usually goes unquestioned; it is also enforced by the way that industrial supply chains work. These age-old design paradigms have been reincarnated in Computer-aided Design (CAD) tools as well as Computer-aided Manufacturing (CAM) technologies where homogeneous materials are formed into pre-defined shapes at the service of predetermined functions. Inspired by nature, a new design approach has recently emerged called material ecology that aims to establish a deeper relationship between the design object and its environment. The key to this approach is the realization that the environment and the design object interact through multiple dimensions and a spectrum of environmental variables. A simple analysis would show that the dimensionality of environment space is much larger than that of conventional design space. This dimensional mismatch leads to and results in an ecological mismatch where design objects do not quite fit in their respective environments. Material ecology aims to bridge this gap by increasing the dimensionality of the design space throughmultifunctional materials, high spatial resolution in manufacturing and sophisticated computational algorithms. In doing so, a holistic view of design emerges that considers computation, fabrication, and the material itself as inseparable dimensions of design which results in objects that are ecological from the outset. The papers included in this Special Issue are authored by research groups from around the world and introduce a suite of biologically inspired digital fabrication tools, techniques, and technologies enabling designs that have a profound connectionwith an environment. Kristensen et al. (ETH, Zurich) introduce a novel fabrication method combining slip forming and digital fabrication for concrete structures. In this additive fabrication process a robotic arm is implemented to form the concrete while it hardens, eliminating the need for the complex custom milled formwork and enabling the reuse of themold overmultiple extrusions thus offering greater efficiency and control. Reichert et al. (ICD — Institute for Computational Design, Stuttgart) propose a new approach to the design and construction of material-based sensing and actuation. The authors focus on