1.6 Modular plastic façade made of prefabricated sandwich elements. 1.7 Market hall, Argenteuil near Paris, S. du Château, 1967. The dome measuring 30 m in diameter consists of 30 prefabricated 6 mm thick GrP shell elements mounted on a supporting tubular steel construction. 1.8 “Les échanges” Pavilion, Expo Lausanne, H. Hossdorf, 1964. A modular roof structure made of GrP hyperbolic paraboloid (hypar) surfaces, bonded to a steel frame and pre-stressed.
maTerial ProPerTies of PlasTics
Plastics are a group of materials with a broad spectrum of properties that makes them predestined for numerous different applications. Plastics can be generally divided into four categories of plastics: elastomers and thermosets, which have a cross-linked molecular structures, and thermoplastics that have an uncrosslinked structure. Thermoplastic elastomers (TPE) result from a combination of thermoplastic and elastomeric components and exhibit characteristics of both groups. Depending on the degree of cross-linking, plastics can differ in terms of strength, stiffness and resistance to heat and chemicals. The performance characteristics of individual plastics are generally very specific. Nevertheless, there
are several material properties that can be used to characterise plastics in general. This chapter provides an overview of these properties where they are relevant to the field of architecture.
ForMinG CHArACTEriSTiCS AnD THE MAnUFACTUrE oF BUiLDinG ELEMEnTS An excellent property of many plastics is the ability to shape them freely, which makes plastics ideally suitable for building elements with complex geometric forms. The production of individually shaped special forms, as is often the case 2.1
in architecture, can be comparatively costly. Prototypes made of thermosetting fibre-reinforced plastics with dimensions of up to several metres can be manually manufactured, but this is comparatively labour-intensive and correspond-
ingly expensive. A number of thermoplastic materials can be shaped with the help of rapid prototyping techniques without the need for the complex manufacture of moulds. in this case, the basis for the manufacture of a three-dimensional building element is a digital model. CnC fabrication methods include, for example, 3D printing or milling. These methods are generally only suitable for elements of a limited size. Elastomers and thermoplastics are also suitable for the manufacture of geometrically complex building elements and can be produced industrially in large quantities. The particular advantage of prefabricating elements for the building sector is that constructions can be produced and assembled regardless of weather conditions. in the case of plastics, the creation of the material and the moulding of the element are typically one and the same process. The fabrication process makes it possible to manufacture materials that can be adapted to their expected loads, for example through the localised application and embedding of reinforcement fibres in a resin matrix. Properties such as strength or stiffness can therefore be optimised as required.
Published on Oct 1, 2010
This book seeks to fill that gap by providing an introduction to the structural and design possibilities of plastic. It introduces the mater...