JEC COMPOSITES MAGAZINE - Issue #93 - December 2014 - 16

bridge

A vacuum-infused boxbeam bridge
produced and installed in Japan
The first vacuum-infused boxbeam bridge
produced and installed in Nagano-Ryokuchi,
Fukuoka, Japan, is the result of a cooperation
between Japanese company GRP Construction
and Dutch company Infra Composites.
A successful technology transfer made it
possible to build the bridge directly on site.
The conept has proved to be efficient and flexible

Vacuum infusion
process

G

RP Constructions
(GRPC) has designed
and built hardwood
(mostly pedestrian) bridges
for the Japanese market
for several decades. The
company also built several
composite bridges based on
pultruded elements. Looking for alternative designs
and production processes
avoiding the geometrical and
structural limitations associated with pultrusion, GRPC
contacted the Netherlandsbased company Infra Composites.

Infra Composites has already
designed and built full
composite bridges in the
Netherlands, all based on
the vacuum infusion process
and a structural boxbeam
concept. In this concept,
glass/polyester parts (two
sides, one or more girders,
deck and bottom shells and
bulkheads) are infused and
assembled using an adhesive.
The concept has proved to
be efficient and flexible as
it allows easy changes of geometry and changes between
pedestrian and vehicle loads.

A successful partnership between GRP Construction and Infra Composites

16 jec composites magazine / No93 December 2014

Co-operation

Boxbeam design

Two years ago, a cooperation was established between
GRPC and Infra Composites, who transferred design
and production knowledge
to Japanese engineers. Last
year, a full-scale segment of a
vacuum infusion bridge was
manufactured in the Dutch
company's production facility during a two-week session
in which GRPC workers
were trained. In parallel, various smaller test articles were
produced such as bridge deck
samples and parapet attachment sections.

The boxbeam design for the
Japanese market was kept
identical to the original
design, with two exceptions
due to local challenges. First,
the presence of an aggressive
type of fungus in certain districts in Japan prohibited the
use of a balsa wood core for
the sandwich deck. Fibre-reinforced polyurethane cores
were used alternatively. For
higher loaded traffic bridges,
a multiweb bridge deck
design will be employed.
Second, the bridge supports
also needed to be able to
keep the bridges in place during the typhoon season while
still allowing for thermal
expansion.

A few weeks later, a complete
bridge was manufactured
in GRPC's new dedicated
production facility in Japan
under the supervision of an
Infra Composites project
manager. This bridge was
used for extensive mechanical testing and for promotional activities, while the
employees were further
trained during the production session.

This year, GRPC sold and
produced its first vacuuminfused boxbeam bridge
and installed it in NaganoRyokuchi in Fukuoka. More
will follow shortly. n
More information:
www.infracomposites.com
www.grpc.jp
http://www.infracomposites.com http://www.grpc.jp
JEC COMPOSITES MAGAZINE - Issue #93 - December 2014

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