Beyond its transparency, glass offers a large potential to fulfill load-bearing functions. Timber-glass composite elements take advantage of the high stiffness and strength of glass. At the same time, their post-breakage behavior increases significantly compared to the brittle failure of a pure glass. This study relates especially to timber-glass composites where the composite action is obtained via a linear bondline connecting the glass pane to a timber frame. The full potential of these composite elements arises from the use of adhesives of
medium and high stiffness which exhibit rather small deformations compared to e.g. structural silicones. A central objective is the assessment and the optimization of the bondline properties with respect to stiffness of the adhesive. This paper summarizes the results of an in-depth study on commercially available adhesives and evaluates their general suitability in timber-glass composites. Material properties of the adhesives were determined by thorough mechanical testing of the bulk material under varying conditions, typically encountered in façades. The potential use in glass-timber composites was further evaluated using small bonded specimens comprising birch plywood or massive pine wood. Failure modes were categorized in order to ascertain
the influence of the timber strength on the load-bearing capacity.
In order to guarantee reliable results from various sources, parts of the tests were executed repeatedly at different laboratories. Results were compared and validated throughout the project. Hence the results of this study provide a reliable basis for material models used in e.g. numerical analysis and engineered design solutions. The study presented here is a part of the WoodWisdomNet project “LBTGC − Load Bearing Timber Glass Composites”.