Reinforced glass beams
lecture for Verre 2006
Dr.ir. F.A. Veer
1
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.
2
Cathedral of Notre dame , Paris
3
Glass in architecture
• Although these windows are very dramatic
they need extensive supporting masonry
as they weaken the structure.
4
Crystal palace, London , 1851
19th century greenhouse, Madrid, Spain
5
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.
6
Grand Serres of cite des sciences et de l’industrie at la Villette
7
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 ?
8
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
9
Glass beams
• Monolithic annealed
float glass
• Tempered float glass
• PVB laminated
tempered float glass
• Sentry glass
laminated tempered
float glass
• Cast resin laminated
tempered glass
• Polycarbonate
laminated glass
• Carbon fibre
reinforced glass
• Stainless steel
reinforced glass
10
ING office, Budapest
11
Glass museum, Kings Wingford, England, PVB laminated roof beams
12
Apple store, New York , use of Sentry glass
13
Wolfson building of the medical faculty of the university of Glasgow
14
IHK building , Munich
15
Carbon fibre reinforced glass roof beams for the loggia di vicari
16
Stainless steel reinforced glass beam after testing
TU Delft all glass paviljon 2004
17
Failure behaviour
stress
Monolithic glass
PVB laminated glass
Reinforced glass
PC laminated glass
strain
18
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,
column’s etc. as well as the technology to
put it together.
19
1997
Glass polycarbonate beam
first loading
5000
4500
segmented glass ___ test 1 ... test 2 --- test 3
4000
3500
Force (N)
3000
2500
2000
1500
1000
500
0
0
1
2
3
4
5
displacement (mm)
6
7
8
20
Glass
2001
Polycarbonate
Stainless steel
21
2002
22
23
24
2002
25
Glass box section reinforced beam, 2003
26
2003
Glass T-section post-tensioned beam
27
2004
28
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 :
29
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
30
Ease of manufacture
31
Required volume of reinforcement
thickness
32
Reinforcement configuration
33
Adhesive type
Stainless steel reinforced glass
bonded using GB 368 adhesive
Stainless steel reinforced glass
Bonded using araldite 2013
adhesive
34
configuration for the glass
35
configuration for the glass
36
maximum length
37
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
38
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
39