Reuse of entire insulating glass units (IGUs) is a high-level circular strategy to reduce material use, energy demand, and CO2 emissions from manufacturing, but remains little studied. This study explores the technical reuse potential of 930 argon-filled double glazed IGUs in 43 Dutch buildings, using residual argon gas concentration as screening criteria for reuse. It assesses associations with IGU age, orientation, building, and assembler, and reviews the scalability and practicality of the proposed screening method. The reuse potential is explored through three perspectives: an availability-driven approach, a performance-driven threshold (T85) of ≥ 85
The increasing use of all-glass structures has been enabled by advances in glass manufacturing, allowing glass beams to be employed as primary load-bearing elements. Owing to the intrinsic brittleness of glass and the absence of visible pre-failure indicators, ensuring adequate post-fracture behaviour is essential to maintain structural integrity and prevent progressive collapse. This paper presents an experimental investigation into the post-fracture behaviour of four full-scale glass beams from realised projects constructed between 2012 and 2026 in Ireland, France and Italy. The study evaluates the residual load-bearing capacity of different laminated glass configurations, focusing on the influence of laminate typology, assembly techniques and redundancy systems. Particular attention is paid to the role of alternative load paths in preserving structural stability after localised failure. The results reveal substantial differences in post-fracture performance between the tested configurations, highlighting the critical importance of material selection and structural detailing. The findings contribute to the definition of robustness and damage-tolerance criteria for load-bearing glass elements and support the experimental validation of numerical design approaches.
The Museum of Anthropology is one of Arthur Erickson's most famous designs and an outstanding example for Brutalism Architecture in Canada. Due to seismic issues of the original concrete framing, the Great Hall of the Museum was to be renovated. The original primary concrete structure could not be adequately strengthened, and it was decided to re-build this particular portion of the building on a base-isolated platform. As part of the re-build, the authors re-imagined and engineered a new structural glazing system that maintains the original design developed by Pilkington for Arthur Erickson, but employs today’s design principles for structural glass. The structural glazing landscape has evolved vastly over the five decades since the museum’s initial construction. Higher wind and seismic loads along with requirements to provide safer glazing systems have been met with advances in glazing technology, including larger format panels and stiff interlayers. Maintaining the original shape and size of the glass fittings while accommodating seismic drifts of the Great Hall and existing adjacent wing required innovative thinking, especially at the inside glass corners. Glass fins nearing 12 m tall required careful consideration of site conditions and installation tolerances. The large-scale Performance Mock-Up (PMU) was replaced by a series of smaller ‘micro PMU's’ that represent key elements of the facade. The authors and hardware manufacturer developed a set of three small scale test assemblies to verify strength, drift accommodation and water tightness.
Current standards suggest characterizing the distribution of glass fracture strength using co-axial double-ring standardized tests. While several international standards do not specify a minimum test number, ASTM C1499-19 recommends conducting at least 30 valid tests (defined as tests where fracture initiates in the inner ring). In practice, the results of invalid tests are often discarded. However, the invalid tests still hold information on the fracture strength, and neglecting them can lead to a biased estimation of the latter. This study proposes a Bayesian inference approach to extract and incorporate such information in glass strength characterization. The approach is applied to existing datasets at ambient and elevated temperatures, examining how the test number influences the coefficient of variation of the characteristic fracture strength used for design. The results show that discarding invalid tests may bias glass strength estimates. Furthermore, for the considered dataset at elevated temperatures, incorporating invalid tests enables achieving the same precision level as implied by the standard with fewer tests. These results show that the proposed approach can improve testing efficiency and refine characteristic fracture strength predictions. Finally, the study quantifies the impact of incorporating invalid tests on the structural reliability of a slab under different load ratios. Results show that ignoring invalid tests leads to an overestimation of the reliability index. This finding highlights that invalid tests should be considered for more robust reliability evaluations of glass structures.
In 2017, a client approached Old Town Glass, a California glass contractor, with a project: A cliffside home with a curved facade featuring 50 m of cold-bent glass with an inflection pane bridging concave and convex sections. With the foundation already built, they needed a cold-bent laminated, s-curve insulated glass unit (IGU) to minimize anisotropies and optical distortions for their unobstructed view of the Pacific Ocean. Cold-bent laminated glass requires panes of glass to be individually bent and laminated together in the autoclave, allowing them to hold shape without structural silicone, supporting framework, or significant heat required for hot-bending. Unlike typical single-radius cold bending, this project required double curvature, demanding new calculations beyond existing FEMs to predict rebound and final geometry. Tight tolerances were critical as minor deviations could misalign the inflection area, leading to inaccuracies and structural stress. To ensure precision, the team created a full-width mock-up and used 3D point-cloud scanning, 3D-printed templates, and overlays to refine adjustments before fabrication. The rugged coastal job site location added complexity. Custom seismic brackets were needed, truck deliveries navigated narrow highways, and installation required careful planning to account for unpredictable weather, long commutes, and logistical disruptions from COVID-19. Despite these challenges, the s-curve glass was successfully installed in June 2023, following over six years of collaboration among sedak’s R D team, EOC’s facade engineers, Sky-Frame, Old Town Glass, and others. This project demonstrates the feasibility of cold lamination bent glass with double curvature and expands the understanding of what can be achieved with this fabrication method, informing future research and applications in complex curved glass design.
