Durable pedestrian bridges have become one of the most important applications of ultra-high performance concrete (UHPC) in the Netherlands. In 2015 FDN engineering designed and built an UHPC pedestrian bridge called 'Zwaaikom', over a water channel in the city of Eindhoven, The Netherlands. This project has shown that UHPC can be competitive with other materials such as timber or composite for this specific application. The proposed bridge won an open tender thanks to its exceptional durability and attractive architecture, which fits into the surrounding.
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thema
22 130
4440 4440 4440 4440 4440
25 637
500 500
5% 5%
The strongest
UHPC bridge in
the Netherlands
1
Durable pedestrian bridges have become one of the most important applications of ultra-high performance
concrete (UHPC) in the Netherlands. In 2015 FDN engineering designed and built an UHPC pedestrian bridge
called 'Zwaaikom', over a water channel in the city of Eindhoven, The Netherlands. This project has shown
that UHPC can be competitive with other materials such as timber or composite for this specific application.
The proposed bridge won an open tender thanks to its exceptional durability and attractive architecture,
which fits into the surrounding.
2
thema
The strongest UHPC bridge in the Netherlands 3 2017
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1000
3800
3500
80
100 150 400
445
30
800
stirrups 10 x Ø12
280
660
Ø12 x Ø10/100 x 100
Ø10 x Ø10/100 x100
prestressing tendon 13 x 0.6'-150 mm 2 / 1860
15
100
Ø10 x Ø10/100 x100
15
105
80 21 hollow body of the girder
UHPFRC C170/200 + steel bres
Design
The bridge, fully made of ultra-high performance concrete
(UHPC) C175/190 class, has a total length of 25.60 m, a clear
span of 21.40 m and a total width of 3.80 m. The bridge deck is
only 400 mm high. This corresponds with the slenderness of
1/55.
The cross-section of the bridge with a hollow girder box can be
seen in figure 2. The hollow part is filled with polystyrene,
which was used as a lost formwork during the production
process. The average thickness of the cross-sectional walls is
around 100 mm. The rib in the middle of the cross-section
does not have a structural function. It is just for better control
of concrete pouring in the bottom slab.
Apart from having compressive strength higher than 175 MPa,
UHPC contained steel fibres which made it very ductile. In
order to fully utilize advantages of its high compressive strength,
beside traditional reinforcement, pre-stressing is applied.
The bridge deck was post-tensioned with five tendons (photo 12),
each with 13 strands. The cross-section is hence subjected to
the relative large compressive force (around 13 500 kN)
resulting in large stresses (around 17 MPa). In order to
accommodate the anchor system and withstand large split-
ting forces, a solid end beam was designed at both ends.
Additional reinforcement was applied in the bottom slab to
avoid pull out of the ducts from concrete since the cover of
the duct was only 30 mm.
The railing elements were also made from UHPC, with a cubic
compressive strength of 150 MPa. The railing has a bionic form
with randomly distributed struts. (fig. 6). The railing does not
contribute to the general load bearing capacity of the bridge,
but it must still withstand several loads. Thanks to the high strength of the concrete, the railing struts are only 50 mm
thick. The anchor bolt rails have a zinc protection against the
corrosion.
Material
The concrete mixture contains large amount of binder (white
Portland cement 52.5 with a rapid hardening process) and a
high-quality calcinated aggregate (bauxite), with a grain size
0-6 mm. The water-cement ratio was 0.17. The proper hydration
and thixotropic behaviour in the fresh state was assured by
additives such as super-plasticizer and un-hydrated micro-silica.
The biggest challenge was to reach the required creamy-beige
colour of the concrete, because the natural colour of the UHPC
is dark grey. This was This was achieved by using a combination
of white Portland cement, microsilica and a corresponding
mixture of the pigments. Therefore, an additional experiment-
Jan Falbr
FDN Engineering + Construction
1
UHPC pedestrian bridge 'Zwaaikom' in Eindhoven
2 Side view of the bridge
3 Cross section of the bridge deck
4 Longitudinal cross section of the anchor head
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3
The strongest UHPC bridge in the Netherlands 3 2017
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60
70
mortar C110/130
Ø 8 mmepoxymortar
anchor bolt M12/8.8-75 mm
+ ring 37/13/3 mm
anchor rails
165
welding
110
railing element
deck
Ø 14 mm
455 455
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4440
R = 213 220 m 4419
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89.4°
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5 10 15 20 time [s] acceleration [m/s
2]
excitation from joggers limit
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