2 Glass in architecture Glass has played an important role in architecture as the material that opens up a building to light. An important example are the great rose windows of the medieval cathedrals.
3 Cathedral of Notre dame, Paris
4 Glass in architecture Although these windows are very dramatic they need extensive supporting masonry as they weaken the structure.
5 Crystal palace, London, th century greenhouse, Madrid, Spain
6 Glass in architecture Although glass appeared to take a leading role it was still only a material that separated the interior and exterior. It was only some twenty years ago that glass started to be used in a limited structural role.
7 Grand Serres of cite des sciences et de lindustrie at la Villette
8 Glass in architecture This marks a transition from non-structural to limited structural use of glass. This also raised the important question: How far can we go in using glass as a structural material ?
9 Glass as a structural material It also raises the question of what loads we can put on glass in : –Tension –Bending –Compression Bending will be the focus of this presentation
19 Stainless steel reinforcement In 1995 the ZAPPI research program started. Goals was to develop safe transparent components for a transparent building of 20×20×20 meters. This means beams of large span, columns etc. as well as the technology to put it together.
20 Glass polycarbonate beam 1997
26 Glass box section reinforced beam, 2003
Glass T-section post-tensioned beam
29 Further improvement Although the 2004 result showed large and safe beams can be made research is continuing in several directions. This with the following aims :
30 Further improvement -how to increase the ease of manufacture -what is the required volume of reinforcement –what is the optimum configuration for the reinforcement -what is the optimum configuration for the glass –What is the best adhesive for the reinforcement –What is the maximum length that can be attained
31 Ease of manufacture
32 Required volume of reinforcement thickness
33 Reinforcement configuration
34 Adhesive type Stainless steel reinforced glass bonded using GB 368 adhesive Stainless steel reinforced glass Bonded using araldite 2013 adhesive
35 configuration for the glass
36 configuration for the glass
37 maximum length
38 Conclusions The results so far show that reinforced glass beams : –can exceed the 6 meter length limitation imposed by the standard glass panel size –can have a build in structural safety mechanism which shows considerable deformation after initial cracking and thus cannot collapse spontaneously –can in theory be used as structural member of the main load bearing construction –have a length limit of about 20 m –can result in innovative architectural solutions
39 Conclusions The main obstacles to introduction of reinforced glass beams are: –the lack of an adequate knowledge base on which to design the components –the problem in joining the glass components together –the lack of knowledge about these components at the architecture and engineering level –the lack of clearly applicable building codes for the regulatory body –the need for specialised staff and expertise for the contractor