Civil Engineering Reference
In-Depth Information
Chapter 3.5
Glass fibre reinforced polyester
and glass fibre reinforced cement
This chapter deals with cladding
made from glass fibre reinforced
polyesters (GRP) and cements
(GRC). These are undoubtedly
products of the second half of the
twentieth century. Other reinforcing
materials may be occasionally
encountered, such as steel or carbon
fibres; but rarely, so they are not dealt
with in this topic.
Although infrequently used for
housing, the best known GRP system
was Resiform (Figure 3.75) of which
some 1,800 dwellings were built, the
material was more often used as
cladding for other building types,
including some prestige buildings.
GRC is now more widely used in
France and Spain than in
the UK.
Characteristic details
Basic structure
Glass fibre reinforced polyester
(GRP)
GRP is a composite material
consisting of a resin reinforced with
glass fibre, sometimes with fillers
and pigments of various kinds. On its
own the resin is brittle, but the
inclusion of a glass fibre produces a
tough, high tensile strength material
of low weight.
Panels of GRP are produced by
building up layers of liquid resin
and glass fibre mats or fabric, and
then compacting the whole with a
roller. Alternatively, the material
can be built up by simultaneously
spraying the resin and the fibres.
The resin reacts with added hardener,
causing it to set. Glass fibre
reinforced polyester panels can be
produced to a wide variety of sizes,
shapes and surface finishes. The
material particularly lends itself to
panels with returned edge profiles
and concave or convex surfaces,
giving strongly modelled façades
(Figure 3.76).
The manufacturing process
produces panels with a wide variety
of properties. A major difficulty in
assessing this material, as used in
cladding, is that seemingly similar
panels can have widely varying
properties, depending on the resin
type, glass content, compaction
efficiency and curing conditions.
The Resiform system referred to
above consisted of a resin laminate
approximately 15 mm thick into
which timber studs were set, making
storey height panels in a range of
widths up to around 7 m.
Figure 3.76
GRP panels can be formed into a wide
variety of sizes, shapes and surface
finishes
Figure 3.75
Three storey Resiform GRP clad housing
