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Ferro-cement and
epoxy/grp combinations |
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Either cement on it's own or sand and cement, are mixed
with epoxy to create an 'epoxy mortar', is marketed by many manufacturers
around the world under various brand names. There are also manufacturers
who market it with added shredded glass, carbon fibre and various
other stranded materials, used mainly for bridge and building
repairs. The mixing of resins and concrete has to be very carefully
considered for two main reasons. First their expansion rates
are very different. (Steel and a concrete/plaster mix, expand
at virtually the same rate). Secondly resin mixes and concrete
mixes have reversed osmosis conditions. |
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There have been many attempts and experiments to improve
'Steel reinforced plaster' (ferro-cement), and 'glass reinforced
plastic' (fibreglass), by mixing the two in various combinations.
Basically trying to combine the long life and high impact resistance
of ferro-cement, with the weight advantage but rapid deterioration
of fibreglass. Most of the experiments were done during the 1950's
and 60's. The experiments were usually in the vein of either
looking for reduction in weight, increased flexibility or increased
strength/impact resistance. In the marine world, time proved
that there were major drawbacks with resultant osmosis and expansion
problems. The former a major obstacle to the use of resins. It
is interesting to note that many Scandinavians seem to have taken
on the subject almost as a crusade, and some to this day are
still experimenting. Although I have to say in general, it still
seems to be just covering old ground. |
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I must point out however that with regard to small areas
of repairs the use of epoxy as a compound (not mixed with the
plaster), but as an entity attached. Has a place and is acceptable
under certain circumstances. |
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It would certainly be a breakthrough if you could resolve
either the heavier weight of ferro-cement, or the rapid deterioration
and osmosis problems of fibreglass.
Colin Brookes. mSNAME. advIFIC etc |
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