Durability of Structural Silicone Sealant in Cold Bent Glazing Design

The cold bending of glass in unique facades have been successfully completed in the past using structural silicone glazing (SSG) as the sole method of retention of the bending membrane. The practice still holds challenges with a concern of how a permanent load due to bending can impact the durability of structural silicone sealants. To date, design practices used in cold bending relies on static models based on purposely low average allowable stresses. However, when using finite element analysis (FEA), these average stresses can indicate stress distribution well above the average allowable stress. Different cold bent glass designs were investigated for their structural performance through FEA. A representative lab scale test was also developed to evaluate the SSG used in the cold bent glass. Long term tests were performed to monitor the change in the structural silicone joint to assess its durability by coupling the loading level to the rate of deformation over time. Testing included the use of a high speed camera to monitor the deformation of the sealant during rupture and crack propagation process. Ultimately, the analysis yields more insight to better predictive models for design criteria of structural glazing cold bent glass.