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The Italian architect Dante Bini began his studies on shell structures during the 1960s. He developed and refined a form-finding and construction technique to erect a finished large-span reinforced concrete (RC) shell structure through the use of an inflatable membrane. This system was patented in 1964 under the name ‘Binishell’ and, over the following decades, it has been applied to construct hundreds of domes throughout the world. Bini’s invention fitted perfectly into the Italian post-war tradition, as he was, at the same time, the architect and builder of his structures. A few experimental tests were initially performed in Italy, and the first binishells that he lifted after the patent was filed were also constructed there. Since 1966, as a result of Mario Salvadori’s interest, Bini has been recognised internationally. In 1974 he moved to Australia after the NSW Department of Public Works asked him to realise a set of school facilities using the binishell technology. The construction of concrete shells has always been a difficult and expensive process – the preparation of formworks, as well as the installation of curved reinforcing rods before the concrete is poured, require experience and increase the construction costs. Such problems are particularly relevant in the Australian context, where the use of simple and rapid construction technologies has always been a priority. Dante Bini’s life and the binishell technology have been well documented from the historical point of view. However, a detailed report and contextualisation of Dante Bini’s Australian experience is still missing. A first attempt to survey the Australian binishells has already been published by the authors.2 The focus was on placing Bini’s early work within the previous research on pneumatic structures which began in the 1920s. The narrative of this paper instead starts in the 1960s, a period of great media success for RC shells. First, the origin of binishells is described as a natural consequence of three preceding inventions/patents. A timeline of the events that defined Bini’s emigration to Australia is then provided. A full list of the Australian binishells is also included, with detailed information on the archival sources, major alterations and current conditions.

Timber gridshell structures, such as the Multihalle for the federal garden festival in Mannheim or the Downland Museum, have been the result of a creative–generative process that indissolubly ‘welded’ the structural contribution to that of form exploration. The challenging design and construction issues have been typically addressed and resolved in several inventive ways. However, still now, form-finding and erection of timber gridshells present many difficulties. In this regard, this paper aims to provide a series of novel steps to address some of the main design and construction issues that are associated with ‘actively-bent’ timber gridshell structures. First, the main characteristics of the construction process of timber gridshells are described and the basic theoretical concepts for its numerical simulation, through Dynamic Relaxation method, are introduced. Second, a practical method for sizing the laths' cross-section is presented. Third, a new erection technique for timber gridshells is proposed and applied to the construction of a full scale (prototype) structure, the Toledo gridshell 2.0. Fourth, a new bracing system for the same structure, which was built at the Faculty of Architecture, University of Naples Federico II in June–July 2014, is explained and discussed. The paper also highlights the need for further application to validate the techniques explained here, with particular attention being paid for the construction of large scale free-form structures.

Before the introduction of NURBS-based CAD software and optimisation, the design of form-resistant structures was based on the use of either experimental tools (physical form-finding) or analytical surfaces, and architects were challenged in the articulation of spaces from the intrinsic characteristics/rules of structural forms. An outstanding example of this kind is provided by the Church of Longuelo, which was built by architect Pino Pizzigoni in Italy, between 1961-1966. It was conceived as composed by two major elements – an irregular frame and a set of shells suspended to it. The entire design process was based on the calculation of the frame on which the shells have been just added as a dead load. This paper presents one possible way to redesign the church parametrically. Comparison with the original design is not performed at the final formal level, which can logically differ, but around the concepts behind the project. The aim is to show how current digital design and optimisation tools are affecting the way architects design. But, at a higher level, the purpose is also to highlight where conceptual design is now taking place in the process.

In book: "AAD Algorithms-Aided Design. Parametric strategies using grasshopper", (pp.352-359). Publisher: Le Penseur. Editor: Arturo Tedeschi.

In architecture and structural engineering, ‘form-finding’ identifies the process of designing optimal structural shapes by using experimental tools and strategies, i.e. physical models, to simulate a specific mechanical behaviour.

The reverse hanging method is the oldest and probably most diffused form-finding technique for arches, vaults and shells – a physical model, made with elastic cables or membranes with no rotational stiffness, is first subject to gravitational forces to obtain a structural state of pure tension; such a form, which is called “funicular”, is then inverted to identify the mechanical compression-only situation.

This principle was first mentioned in a publication by Robert Hooke in 1675 . With a Latin anagram, only solved in 1701, he proposed to reverse the curve which was generated by a hanging chain, under self-weight and supported only at its ends, in order to define the optimal structural form of an arch. Such a curve is called “catenary” when the chain presents a constant distribution of weight . Initially confused with a parabola by Galileo Galilei, the catenary was then mathematically described by David Gregory in 1697.

Reciprocal systems based on superimposition joints, i.e. where un-notched bars sits on the top or in the bottom of each other, could be regarded as being intrinsically three-dimensional because of their natural out-of plane development. This paper presents seven of these three-dimensional configurations, conceived and built by the students of the Master of Science in ‘‘Architectural Design’’ at Aalborg University. They have been developed as an integral part of a 2-week workshop, organized and run by the authors during the fall semester 2011. Since physical models are instruments that trigger the exploration of new typologies because of the direct interaction they provide with the designer the students were called to deal with the issue of three-dimensionality in reciprocal systems through scale models and actual scale prototypes.

The concept of transferring forces in a reciprocal way has always been related to the use of timber beams, that is, elongated elements. However, planar components can also be considered; circular tiles, squares, triangles and more articulated or irregular geometrical shapes are all valid alternatives. This report proposes an initial exploration of reciprocal systems based on planar elements in order to guide further morphological studies. It also presents some prototypes, which were developed by the students of the Ecole des Ponts in Paris during two design workshops run in 2012 and 2013.

The construction of concrete shells has always been a difficult and expensive procedure. Preparation of complex formworks, as well as placement of curved reinforcing rods require experience and increase the overall cost. Building concrete shells is even more of concern within the Australian context, where the use of simple and rapid technologies has always been a priority. In the Sixties, Italian architect Dante Bini developed and patented a form-finding and construction technique that aimed to solve this issue, the so-called “Binishells”. This paper investigates Dante Bini’s system, from its conception within the Italian environment until the international success which was reached in the USA and Australia.

In book: "Shell Structures for Architecture - Form finding and optimization", (pp.290-294). Chapter: Appendix C. Publisher: Routledge. Editors: Sigrid Adriaenssens, Philippe Block, Diederik Veenendaal, Chris Williams.

Genetic algorithms are a subclass of evolutionary algorithms. A genetic algorithm (GA) is defined by Goldberg as a “search algorithm based on the mechanics of natural selection and natural genetics”, but another definition, more focused on its way of functioning, is provided by John R. Koza in his 1992 book, “Genetic programming: On the Programming of Computers by Means of Natural Selection”: “The GA is a highly parallel mathematical algorithm that transforms a set (population) of individual mathematical objects [...], each with an associated fitness value, into a new population (i.e. the next generation) using operations patterned after the Darwinian principle of reproduction and survival of the fittest and after naturally occurring genetic operations (notably sexual recombination)”. In other words, in a random population of potential solutions, the best individuals are favoured and combined in order to create better individuals at the nextgeneration.