JEC COMPOSITES MAGAZINE - Special Issue Smart Cities - November 2019 - 31

The new frontiers of composite materials
Today, when talking about composite materials, we mean those
materials generally consisting of
polyester or epoxy resins reinforced with glass or carbon fibres
(GFRP, CFRP).
In Italy, the use of fibre-reinforced
polymers (FRPs) in the building industry dates back to the
1960s, and it was certainly not for
structural use as they were used
by craftsmen to make decorative
panels or architectural details that
reproduced expensive materials
such as ceramics, marble or wood,
therefore hand made. In other sectors such as aeronautics and boat
construction, composites were already used structurally. Over the
years, even for the construction of
buildings, methods have evolved
and partly industrialized, allowing
a much wider use and greater volume production. Advanced and
faster production methods such as
RTM and LRTM allowed the production of higher quality components with homogeneous finishes
that, however, almost always used
short fibres with poor structural
properties.
Pultrusion technology
One of the production technologies that greatly contributed to the
use of composites in construction
is pultrusion, which uses long fibres for the serial production of
linear composite sections, thus allowing the use of FRPs in the actual construction.
Higher volume fractions of fibres
increase rigidity, reducing thermal movement in what used to be
a family of intrinsically thermally
resistant and electrically insulating
materials. These properties are ideal for the construction of thermally-efficient houses that can help
meet the challenge of reducing
CO2 emissions.
As stated by Professor Angelo

The TemporActive Pavilion, Politecnico di Milano.
Construction materials by Top Glass Industries. (Courtesy of Top Glass Industries)

De Tommaso of the School of
Engineering at the University of
Bologna: "Buildings are potentially
important applications for the pultrusion industry. Pultruded profiles
are suitable for composite structures,
forming the structural part that will
be completed with moulded composite panels. The profiles are generally
made of glass fibre composites with
various types of resin matrices. The
use of pultruded profiles in architecture is not as widespread as it should
be due to aesthetic reasons as they are
often considered as "cheap plastic". In
Italy, there is a great potential for the
pultrusion industry but the demand
is still scarce. Professionals are poorly informed and receive very little
training in the use of composites in
their designs. I think that an action
to spread the knowledge and appreciation of these materials among architects combined with professional
training could be useful now that international norms have traced the essential lines for the use of composites".
Ultra-lightweight
temporary building
made of composite materials
Last June, on the occasion of the 6th
Tensinet Symposium 2019 at the
Politecnico di Milano, a very interesting architecture was built by
Top Glass Industries using pultrusion. The TemporActive pavilion
was an ultra-lightweight temporary
building designed and built by university researchers. A bending-acSPECIAL ISSUE Smart Cities / November 2019

tive hybrid structure was designed
to support and shape a flexible
translucent membrane. The structure was 7x12 m, with a height of
about 3.5 m in the mid span, for a
total weight of only 50 kg. The base
structure and the upper curved
part were built with TRIGLASS®
profiles, a series of 75x150x8 mm
"H" beams connected with angle
profiles (45x112x3 mm) to create
a primary and secondary warping.
The entire structure was realized
with pultruded composite materials except for the internal stainless
steel cables. After the symposium,
the structure was rebuilt and reused as a leisure facility for the students in the Politecnico campus.
According to the Composites
Market Report 2018 of the
Composites Germany trade association, pultruded profiles are mainly used for facades but also for the
construction of bridges, window
profiles and staircases, as well as
reinforcement systems, especially
in the construction/infrastructure
sector, in addition to lightweight
construction. The properties of
these materials, such as corrosion
resistance, low maintenance, the
possibility of constructing according to the load, and non-conductivity of current and temperature,
play a central role. According to
the market report, current research
activities focus on fibre-reinforced
inserts for concrete construction
methods (reinforcement, structur-

/ jec composites magazine

JEC COMPOSITES MAGAZINE - Special Issue Smart Cities - November 2019

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Special Issue Smart Cities - November 2019