At Technische Universität Dresden in a research project sustainable and transparent roof constructions have been developed within the last years. At these structures, on the basis of a traditional steel double layer grid all beams in the compression layer are replaced by the glazing. The glazing fulfils a double function. It serves either as the primary load bearing system and transfers significant in-plane loads or as roof covering. The panes are connected by steel knots at their corners and transfer in-plane forces via adjustable contact blocks.
After the main research phase the first commercial project using this new concept was launched in 2007. With a dimension of 15 m x 21 m and an arch rise of 3.50 m it covers the courtyard of one of the Berlin palaces. In autumn 2009 the palace is going to be re-opened to the public.
The design process was attended with extensive testing to obtain an individual approval. This contribution describes the testing at single panes and at a full-scale arch of 15 m span.
Plastics for the in-plane load application into the glass edge and their creeping behaviour were investigated in first tests. The stability behaviour against glass pane buckling was tested at relevant load combinations and the post breakage robustness and the walk-on ability of the overhead glazing ensured by suitable test. Load bearing tests with a total load of 13 tons were applied on one 15 m arch and finished the test series.
The successfully finished testing is the basis for the individual approval and the realisation of the prefabricated roof construction within the last months