Reinforced Cast Glass: Enhancing Post-Fracture Capacity through Embedded Reinforcement

Enhancing Post-Fracture Capacity through Embedded Reinforcement

Abstract

Glass casting displays significant potential for realizing complex, large-scale, monolithic structural elements for the built environment. Yet glass's inherent brittleness and lack of post-fracture load-bearing capacity pose critical limitations for their safe application. Conventional safety strategies developed for float glass are challenging to apply to volumetric components, necessitating the development of alternative methods. Research at TU Delft has investigated the direct embedding of metal reinforcement (with compatible thermal expansion coefficient to glass) during the casting process, an approach similar to that of reinforced concrete. This method improves ductility, structural redundancy, and recyclability while avoiding lamination strategies. This study builds on previous findings and investigates the manufacturability and performance of cast glass elements with embedded titanium (Ti 6Al 4V) reinforcement focusing on the influence of thermal processing and offset reinforcement placement to improve glass metal interaction and avoid exposed metal rebar. A series of casting, fusing and combinations of casting and fusing manufacturing methods were evaluated, also including different firing temperatures, dwell times and glass densities. Combined casting and fusing offered the most reliable method for controlling reinforcement placement whilst higher density glass compositions were found to reduce reinforcement sagging. Reinforced specimens with offset reinforcement exhibited shear dominated failure and improved post fracture behaviour, however, without increasing flexural strength compared to unreinforced specimens. Overall, the study shows that embedded offset reinforcement enhances safety and robustness of cast glass elements, providing the foundation for further optimisation of this novel concept to ultimately unlock potential for large scale cast glass applications.