vacumatics 3d formwork
One of the most important architectural trends of the last two decades is commonly referred to as ‘digital architecture’. This trend comprises digitally-generated geometrically complex, often irregular, yet fluent double-curved shapes (or rather ‘free forms’) in architecture. Although advanced digital manufacturing systems are emerging in architecture, the construction processes in general require some sort of boost to ‘keep up’ with the already heavily advanced (digital) design and analysis processes.
The demand for flexible formwork systems in increasing, partly due to digital design techniques and the associated ‘unlimited’ design potential. Even the most complex geometric shapes can be easily modelled and analysed using advanced software packages. And although there are (digital) manufacturing techniques, the digital design are typically difficult to produce, if possible at all
Curable materials (such as concrete) are considered particularly useful for the realisation of the desired ‘free forms’. The formability and the adaptability of the formwork system of choice, however, are typically considered the limiting factors. Previous research by the author has indicated the potential of so-called vacuumatic structures (or simply ‘vacuumatics’) to be used as semi-rigid formwork systems. Little is known, however, about the specific structural properties and to a lesser extent the morphological formability of these types of structures. Vacuumatic structures typically consist of an (unbound) aggregate core, which is enclosed by a flexible membrane envelope and structurally stabilised by means of an internal underpressure. The research presented in this thesis aims at defining the influence of the individual characteristics of the aggregate core and the membrane envelope on the overall flexural behaviour of vacuumatic structures. Furthermore, the basic structural mechanics is explored with which the flexural behaviour of vacuumatic structures can be explained. Apart from that, this research aims at defining which shaping techniques are considered most effective for using vacuumatic structures as semi-rigid formwork systems for producing ‘free forms’ and customised surface textures in concrete for architectural applications
The structural integrity of vacuumatic structures can be explained in close relation to pneumatic structures. That is, each (closed) body at the surface of the earth is subjected to the atmospheric (air) pressure, which it supports either by a solid interior or by containing liquids or gases, whose pressure balances that of the atmosphere. As the internal air pressure (underpressure) decreases even further, the tightly packed aggregate core will become increasingly rigid, taking up whatever shape it is moulded into. Although typically the filling of vacuumatic structures consists of unbound granular or fibrous material, it is also possible to apply the same principles to a more or less continuous filling, such as flexible sheets (like spacer fabrics, insulation mats, and so on), or rigid panels (like foam, cardboard, and so on)