Development of composite glass beams : a review

In architecture, there is a growing trend to include more transparency in structures. To increase the transparency, structural elements such as columns, beams, floors and roofs can be built in glass. However, glass is a brittle material and weak in tension, making it less evident to function as a key structural element. To provide robust and safe elements, researchers have tried to develop hybrid glass elements in which glass is combined with other materials. For the case of structural beams, composite glass beams were developed. These beams have typically T- or I-sections, in which the web is a glass laminate and the flanges are composed of another material. Both entities are then put together by using an adhesive or a bolted connection system. Also other concepts exist which have a layered section or in which the materials are combined to make trusses. In this paper, all developments and experimental investigations of this kind of glass beams are summarised using a classification based on the combined material. The concepts are evaluated considering load-displacement diagrams from bending tests. Most of the concepts described illustrate beneficial failure behaviour when subjected to bending, meaning significant post-breakage strength and ductility. Several concepts even possess a post-breakage strength that is larger than the initial glass failure load, while demonstrating extensive deformation capacity. With respect to practical applications, the latter concepts can be considered as very suitable as they generally provide significant robustness.