Structural Silicone Joint Dimensioning: ETAG002 and beyond

The joint dimensioning calculation method provided in the ETAG002 was derived assuming a limited deflection of the glass panes and hence a homogeneous stress distribution along the sealant bite whilst high local stress peaks, structure deformation or material ageing were included in a large global safety factor. Today, some of the current architectural trends observed in commercial buildings – e.g. use of large dimensions glass panes or extreme windloads – lead to higher deflection and consequently heterogeneous stress distribution in the joint due to its rotation whereby the ETAg equation is not valid anymore. Therefore, an improved mathematical relationship including among other effects the joint rotation and the hyperelastic character of silicone was recently derived and proposed. Its validity has been verified through experimental testing and FEA of small size samples (H-pieces). The purpose of the present study is to finalize the validation of the previous predictions with physical measurements of various mid to large scale test samples representative of real life elements installed on façades. Besides this confirmation, the performed testing provides insights in the failure mechanism of silicone joints