Experimental failure investigation of a hybrid glass/steel beam

Glass beams are applied relatively frequently as transparent stiffeners for glass facades and roofs. However, an ever returning design problem is the brittle behaviour and related structural safety. As an answer to this question, a hybrid beam system is presented in which the transparency of glass is combined with the ductility of steel. To do so, glass members are bonded to a slender steel frame using structural sealants. In addition, multiple beam segments can be coupled to construct relatively large spans using a connection system incorporated in the steel frames.This contribution focuses on the experimental part of the structural development and on the observed failures on large-scale tests in particular. The main outcomes of the failure analyses address problems regarding adhesion of the sealants, global buckling of the system, Shore hardness of the sealants, glass breakage, time-dependent deformations and strength of the welding joints.Finally, heavily relying on the results and conclusions of these tests and failure analyses, the first project using this system was built during the spring and summer of 2008. The main structural data regarding the applied hybrid beam system are presented as well.