What is Glass Reinforced ConcreteBCM Glass Reinforced Concrete
(GRC) is a thin section concretethat uses Alkali Resistant glass
fibres for reinforcement as opposedto traditional steel. The fact
that the fibres will not rust like steelmeans that there is no real
requirement for cover and noproblems associated with the lack of
it. As such it is possible tomake lightweight elements that have
impressive structural qualitiesyet save up around 65-75% of the
weight of a solid unit. BCM havebeen making quality assured GRC
since the early 1980s
How Strong Is GRC?
The table on the left gives typicalfigures for the mechanical
propertiesof BCM GRC. As can be seen, thecompressive strengths are
better
than normal concrete, the impactstrengths are good, but the
realbenefits are gained from the factthat GRC functions in bending.
Thisenables designers to make stronghollow lightweight
components.
But What About Durability?
There are few construction materials that have been studied in
such detail as GRC. Accelerated ageing tests were carried out in
the early 1980 s when GRC was first introducedand current analysis
reports that real life data supports these initial predictions.
Over recentyears the cement matrix and fibre compositions have been
further refined to improve thequalities of BCM GRC and the results
have been studied by academics right down to thechemical and
nano-technological level. The long term performance of BCM GRC is
now wellunderstood and designers engineer products accordingly. BCM
GRC can be expected toperform equally if not better than pre-cast
as it will not suffer from reinforcement corrosionand subsequent
spalling.
8/8/2019 GRC Durability PDF
2/2
GLASS REINFORCED CONCRETECOMMON QUESTIONS
GRC Q&A 2/2 14-Mar-05
How Will GRC Weather?Where BCM GRC products have a stone faced
finish this isvery similar to wet cast concrete and can be expected
toweather much the same. The integral face mix of BCMGRC products
is comparable to that of large pre-castcladding although a lot
thinner with smaller aggregates.Semi-dry concretes (used mostly for
domesticconstruction) by comparison, have very low cementcontents
and open textures that retain atmosphericpollution and deteriorate
very quickly. In practice, thedesign of the element and the local
environment has astrong effect on how any cladding stands the test
of time.Evidence from architectural GRC that has been around for20
or more years suggest that the weatheringcharacteristics are as
good as any pre-cast material andbetter than semi-dry products.
There are several projectsin London that combine natural stone, wet
pre-cast andGRC that demonstrate how well GRC blends in with
more
traditional materials.
How Can I Specify GRC?
GRC is normally specified by reference to the Specification for
the manufacture, curing and testing of GRC products as produced by
the Glass ReinforcedConcrete Association (GRCA). Standard NBS
section H40contains similar information as does EN 1169 and EN1170.
Specifiers are encouraged to use manufacturersthat comply with the
Approved Manufactures Scheme audited independently by the GRCA. BCM
GRC are themost experienced manufacture of GRC in the UK.
More details can be found at www.bcmgrc.com orwww.grca.org.uk
.
BCM GRC Ltd. Unit 22, Civic Industrial Park,
Whitchurch,Shropshire, SY13 1TT.Tel. 01948 665321 Fax.
01948666381Email. [email protected]
