Aesthetics in Glass Structures, 2004

Physical Aesthetic

Glass is a beautiful chaotic solid, whose ubiquity is a witness to its material versatility and man’s ingenuity, limited only by our incomplete understanding of its material nature. It is a material based on silica, seeded with metal oxides which can render it transparent or opaque, black or white, or virtually any degree between any of these limits. If one looks at right angles at a transparent form of it, we cannot see it, yet its impermeability can control the passage of air, water, noise, dirt and energy: a window between us and our environment, whether we are stationary or at high speed, in a comfortable or very extreme environment. It has particular physical strengths, and by processing it can exhibit great structural performance and load resistance. Glass is reasonably energy efficient in capital terms because it is manufactured and spread thinly around buildings, is recyclable, and has an abundant source supply making it relatively acceptable ecologically.

Architects and engineers can contribute positively to the future. In the context of glass this leads to thinking about new glass products, imagining new aesthetics, and ways to obtain better performance. Glass cracks too easily for its performance to be totally predictable. This fundamental problem of glass as a building material has been contemplated and ten years ago a short paper was written [2] challenging industry to investigate `doping’ glass at the molecular level to overcome the inherent inability of glass to resist crack propagation while retaining the optical properties and surface qualities which we appreciate. Laminated glass does not reduce crack propagation, it can only hold the cracked sheets together.

To develop such a new material would require confidential research either directly with industry, or at a research institution, or collaboratively between both. Some architects dream of a new architectural glass material for the twenty-first century, and its realisation depends upon industry recognizing its potential commercial value. Architectural aesthetics may shift on paper with new philosophies, but it will always require the architect and engineer to manipulate physical materials so we can fully experience the new aesthetic. It is important in all forms of construction to understand the material itself ­ its performance and predictability.

Glass still is unpredictable. We can predict and control its static characteristics, transparency, refractive index, and colour. We can also predict and control glass dynamic characteristics (e.g. photochromic glasses).However, in structural engineering, as in other fields, the fundamental need is to predict behaviour with more and more certainty, to achieve better performance, and to do both with more economy.

Scientists have been using synchrotron and neutron radiation sources to probe different glass structures². This research has not only given us an understanding of glass molecular structures but has also enabled the development of computer modelling of solids and liquids and spatial theories of atomic structure. Computer modelling uses theories of “melting” and “quenching”, and “cracking” to represent the dynamic nature of glass. But, because glass does not have long range atomic order, it poses special challenges to scientists using these analysis techniques to describe the physical and chemical properties of this remarkable and fascinating material.

Increasing knowledge and predictability at the atomic level opens up the possibility of developing new and improved glass types, some of which will be appropriate for architectural application. Certainly, future developments of molecular structures and coatings will play an invaluable role in achieving more sophisticated and economic glass enclosures. As history has demonstrated, our imagination, unhindered but informed, will improve glass constructions in architecture.

2 The University of Wales, Aberystwyth, Institute of Mathematical and Physical Sciences, Materials Physics

© Ian Ritchie – May 2004