Structural Glass Systems under Fire: Overview of Design Issues, Experimental Research, and Developments

Architectural design concepts incorporating glass beams, panels, or generally load-carrying elements and stiffeners for buildings, claddings, windows, and partitions are largely considered in modern high-rise constructions. A multitude of aspects, including motivations related to transparency, aesthetics, illumination, and energy conservation, progressively increased the use and interest for such a still rather innovative constructional material. However, compared to other traditional materials for buildings, standard glass is typically characterized by brittle behaviour and limited tensile resistance. The intrinsic properties of glass, moreover, together with typically limited thickness-to-size ratios for glazing elements, or the mutual interaction of glass components with adjacent constructional elements as a part of full assemblies they belong (i.e., fixing systems, sealants, etc.), as well as the combination of mechanical and thermal phenomena, make glass structures highly vulnerable. Special safety design rules are hence required, especially under extreme loading conditions. In this review paper, a state of the art on structural glass systems exposed to fire is presented. Careful consideration is paid for actual design methods and general regulations, as well as for existing research outcomes—both at the material and assembly levels—giving evidence of current challenges, issues, and developments.