Previous Work

The research and development work at the Institute of Building Construction focuses on the development of structural adhesive joints, as well as on the asso­ciated theoretical and experimental studies. The first tests on glued frame cor­ners supplied promising results; the adhesive joints remained intact, whereas the glass failed [14]. Based on further investigations, the first research results were transformed into a building project that up until then was unique in Germany.

A highly modern helium liquefaction unit was set up at the Leibniz Institute for Solid State and Materials Research (IFW) in Dresden in 2009. The project included an all-glass enclosure for the historical helium pressure vessels (which are, however; still in use) in front of the institute building (Fig. 2(a)). Load­bearing adhesive joints are used exclusively to connect the individual glass ele­ments. Without any opaque components or visible forms of connection, this housing represents a complete departure in Germany in terms of both building legislation and building technology. The primary structure of this glass pavilion consists of four glass frames of the type described above. These support the infill panes of glass and constitute the lateral bracing for the structure. A transparent, UV – and/or light-curing acrylate adhesive was used for connecting the individ­ual frame elements. Linear structural sealant glazing (SSG) silicone joints con­nect frames and infill panes [15].

This project demonstrated the efficiency of such adhesive joints. In addi­tion, specific application options could be presented to a wider circle of industry professionals with the help of design studies (Fig. 2(b)). Beside gaining valuable

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insights into the structural and material behavior, the numerous tests also pro­vided a wealth of experience on the production of such joints.

Nevertheless, a number of questions remained unanswered, which had to be addressed in further research. For example, so far it had been necessary to heat the glue cartridges and the glass to reduce the viscosity of the adhesive dur­ing application. Owing to the shrinkage in the volume of the adhesive, the prep­arations for the adhesive joint and also its intermittent curing were both very time consuming [15]. Therefore, a series of tests was carried out to assess the suitability of other promising adhesives. Studies involving the numerical simu­lation of glued frame corners, and aimed at optimizing the method of producing the joint, were also carried out. And a new construction project enabled further research results to be applied in practice and, hence, increase the acceptance of gluing in the building industry.