Crystal Clear Structural Glass Bonding: Connecting People to the Surrounding City

Jongmin Kim
Facade Design Specialist
Dow Corning Corporation, Chicago

The tall buildings of today use structural silicone in unitized curtain wall construction to maintain specified façade requirements for thermal performance, air infiltration, water infiltration, seismic performance, and impact mitigation. This method provides greater design flexibility, as well as improvements in cost and quality control. Technologies have evolved with silicone crystal clear adhesive materials that structurally bond glass to glass, and are suitable for engineering and exterior use. The structural properties of crystal clear adhesives are used to optimize the design to maintain structural, weatherproofing, impact and seismic performance. Increased design options to bond façades to structural glass supports with transparent adhesives provides designers with the artistic option of incorporating the aesthetics of the building with the existing environment, all while allowing increased transparency to the exterior environment, thus connecting people to the surrounding city. These new transparent design options were discussed along with the engineering test data for substantiation. Benchmarking transparency of the adhesive against lighting industry standards for heat, damp heat, and thermal shock in conjunction with accelerated aging to ASTM C1442 show that the material retains excellent transparency and non-yellowing characteristics. Examples of façade design and their benefits were also presented.