The Airshell prototype: a timber gridshell erected through a pneumatic formwork

Alessandro Liuti¹, Sofia Colabella², Alberto Pugnale³

¹Faculty of Architecture, Building and Planning, University of Melbourne, MSD Building, 3010 VIC, Australia

²Structural Xploration Lab, EPFL, Fribourg

³Faculty of Architecture, Building and Planning, University of Melbourne

This paper presents the construction of Airshell, a small timber gridshell prototype erected by employing a pneumatic formwork.

Inspired by the work of Frei Otto and Dante Bini, the technique is based on a pneumatic membrane and an Arduino® board – the former used as dynamic formwork and the latter to monitor both the structure height and the membrane pressure throughout the process.

The prototype was erected in Pesaro, Italy, in December 2016; the design replicates a gridshell built in Lecce in 2009 by the Italian company Gridshell.it, which was built through a more conventional pushup technique.

A comparison between the two erection methods is therefore proposed in terms of construction speed and accuracy/precision of the built form.

Design and technological aspects, as well as time frame and budget of the proposed construction technique are detailed within the text.

The paper also discusses the relationship between the digital simulation of the erection process, which was already formulated by Liuti et al. in 2015, and the actual results achieved.

In shell and gridshell architecture, analytical surfaces, as well as reverse hanging models and other form-finding methods have been used for decades, if not centuries, as the main driver of the design process.

However, although the structural forms that result from these methods are intrinsically faithful to the nature – and behaviour – of construction materials, they do not necessarily translate into built forms straightforwardly or in a rational way.