Prediction of Seismic Failure of Silicone Sealant in Two-Sided Structural Sealant Glazing Systems

A research project was undertaken at Pennsylvania (Penn) State University to study the simulated seismic performance of Structural Sealant Glazing (SSG) used to adhere glass panels to common curtain wall framing systems. In the most common type of SSG curtain wall construction, referred to as two-sided SSG, two glass panel edges (typically opposing vertical edges) are adhered to the support framing using structural sealant, while the other glass panel edges are mechanically fastened to the support framing. In this study, full-scale two-sided SSG curtain wall mock-ups consisting of three, side-by-side glass panels were subjected to cyclic racking displacements to characterize their performance and to identify sealant and glass component failure modes under serviceability and ultimate racking displacement conditions. In addition to testing, kinematic-based models were developed to predict failure states (e.g., structural sealant failure) of the SSG curtain walls. This paper discusses the details of the predictive model and its evaluation on the basis of comparisons with mock-up test data. The model developed gives good estimates of the observed sealant failure drift. Conclusions and recommendations regarding appropriateness and limitations of the predictive model are provided.