Structural behaviour and micro-structural characteristics of coloured kilned glass panels

Abstract

AbstractIn recent years, the architecture, engineering and construction industry is increasingly embracing digital design approaches and robotic production methods. This is as well noticeable in the façade design sector, especially when it comes to architectural design tasks dealing with complex geometries or adaptive components. Although glass is mainly used in facades due to its transparency, it often determines significantly the aesthetic appearance of a building and has to control the transmitted light and the visibility between exterior and interior. Recently, a novel method for producing polychromatic glass panels by fusing granular glass powder of different colours onto the surface of annealed float glass in a kilning process was developed at ETH Zurich. By using a multi-channel tool attached to a robotic arm for placing the granular powder onto the glass surface, digitally designed patterns can be realised precisely and repetitively. This paper focuses on the structural behaviour and the micro-structural characteristics of this novel type of coloured glass panels for façade applications. The bending strength of such glass panels was determined based on four-point-bending tests and was compared to that of annealed float glass. A non-negligible decrease in the bending strength was observed. Furthermore, the reasons for this reduction in structural performance were analysed based on microscopic investigations. It was observed that both the kilning process and the density of deposited granular powder had an influence on the surface microstructure. The presented results are essential for the production of polychromatic kilned glass as well as for future applications of this type of glass panel in façades.