Agriculture Reference
In-Depth Information
It is unfortunate that this product has not
been distributed more widely outside of
Germany.
need to be developed that are adapted to the
blocks produced, whether they be weight bear-
ing or not. Finally, these techniques will need
to take into account the regulatory climate and
allow the building industry to use these prod-
ucts with confidence, while satisfying the needs
of their insurers.
The production of building blocks made
from hemp cement is marginal at present.
Important French and European research pro-
grammes are under way, however, to address
the questions outlined above.
17.5.2
Hurds in bulk
As we have seen already, the properties of
hurds make it an excellent thermal and acous-
tic insulator. Its use as a bulk insulator that is
poured easily provides a simple and efficient
method that is well suited to the insulation of
floor spaces. Techniques making use of insuf-
have not really been developed further.
The hydrophilic character of hurds does
necessitate that appropriate precautions be
taken. All commercial uses must be accompa-
nied by a guarantee that this issue has been
addressed.
In certain situations, a fireproofing treat-
ment is likely to be required. Despite the utility
of this product, manufacturers have ceased to
produce it - or have gone out of business - so
such products are currently unavailable. It is
hoped that this situation will not last long.
17.5.4 And also…
The characteristics of the co-products of hemp
fibre and hurds have been highlighted and dis-
cussed frequently. These characteristics allow
us to envisage the development of numerous
other construction materials provided they can
attract the interest of a developer and meet
the technical and economic demands of the
market.
PANELS OF AGGLOMERATED HURDS
.
The manufac-
ture of chipboard panels is an established
industry that makes use of all the waste from
sawmills as well as entire trees.
The technology that has been perfected
over the years has remained simple and low
cost (attributable largely to the low cost of
the raw product). A volume of wood parti-
cles (chips) is mixed with glues or polymer-
izing resins and compressed. This produces
boards that are particularly rigid, given their
thickness.
These panels [agglomerated hurds panels]
have a lower density and lower thermal resist-
ance than those made of wood. The use of
hemp to produce such products is not new, but
the lack of economic development afforded to
this product has not encouraged hemp workers
to pursue this option. Programmes under
development in France and Germany are again
studying this option. In order for these prod-
ucts to have a future, the materials produced
will need to have environmental and technical
specifications which give them an advantage
over similar panels made from woodchip that
are marketed at very low prices.
17.5.3 Masonry blocks
made of hemp cement
Contemporary construction makes extensive
use of masonry blocks. They are used in 90%
of individual house builds and, as early as 1990,
the production of hemp blocks followed hot on
the heels of the first hemp cement. Setting
aside the poor fluidity of hemp cement, which
can cause difficulties when transporting the
freshly prepared product, the production of
blocks poses relatively few problems. This is
particularly the case where production machin-
ery is available, as is the case throughout much
of France.
This line of development represents an
important potential for the industry to explore,
providing it can respond to the following con-
cerns. Firstly, the problem of drying times must
be addressed. Hemp cement dries slowly and
this is incompatible with industrial production
processes. Secondly, building techniques will
