Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
T~le present invention relates to a building
matcrlal composed Of solid particles of compact form
SUCll as sclnd, gravel, stones, pieces of rocl~s, etc...
The invention also relateq to the applic-
ation of this matcrial to the construc-tiotl of
embanlcments, road or ground s~ iaci.ngs or of
foundation masses over a loose gro-Lrlcl.
The invention further relatcs to a metllod
and installation for producing this rnateri.al.
Materials ~re kno~.~to be used in bui.ldins
works and in ci~il engineerinS in particula.r, which
are composed of particles ol` varying si~es bonded to-
gether by means of a binder such as cement mortar,
bi.tumen, resitl~ etc. Ordina~y concrete ancl bitumen
concrete are exarnples of SUCIl m~terials. The particles
constitwting this family of materials can be of any
nature.
The properties of these materials can be
altered elther by selecting the particles, or by
altering the qualltity and/or the quality of the
binder. lt is noted from experiments that high
resistances are obtained in that family of materials
when usins a graded distril~ution of tlle constituent
particles SUC]l that the visible clensity Or the
resulting materi.al is close enou~ll to the average
density of tlle particles proper a}ld by Usillg a
quantity of binder such that it lills most
of the empty spaces left by the assembling of the
particlc3. Tllis result is expl.ained by the fact
that both these conditions contribute to i.ncreasillg
the contact surface betweell the l~inder an~l-the
particles and consequently the number of bonds exist-
ing between the latter, wh.ich condition is necessary
for the compo~ition to have a good rnechallical
strength.
;~ '
A first consequence of this is that, with
a ma3s of particle~ of 1~hich the ~raded ~listribution
is such th2t ~he most compact arrangement that can
b~ obtairlcd ~Yith these particles cotuprise~ a high
proportion of empty spaces, ~ large quantity of binder
is necess~ry, which can become expensive or ~ive a
physical performance too close to that Or the binder
proper, or else give rise to difficulties in the
practical preparation of the mixture. l'his explains
how a number of available unbonded rnaterials~
whether they are natural or the result of human
activities (~uch as industrial wastes or by-
products) are ~lsuitable for a nulnber of uses in
the form of bonded materials because of their in-
adequate graded clistribution.
A second consequence is that a material
of hiSh resistance because it comprises few empty
spaces will have a poor permeability; this being
a disadvantage in some applications.
ZO The small proportion of empty spaces, nec-
essarily associated to the increased mechanical
strength which can be obtained with specific
components, can have other consequences wllich are
bad in some applications : excessive rigidity,
high heat conductivity, high voluminal mass, etc.
Moreover, the said ~lown materials -
constituted of particles and bincler - need to be
produced,by mixin~ and kneading the two components,
this at least having two rnain consequences:
- the binder, when mixed, shoulcl be in such
a physical state as to allow the mixing: liquid or
pasty form, or po~der form, etc. ~he materials
suitable in principle as binders cannot all come in
those l~articular forms, because of the physical limits
(such as temperature) imposed by the particles
6;~1
whicll need to be bound;
- the physical state in which the binder
should be to allow the mixing can lead to physical
and mechanical characteris-tics of the binder in the
firlal ma-terial that are far removed from the
rnaximal characteristics that it could show had
it been used in other conditions. Indeed, a lot
of materials need, in order to improve their
potential ~nechanical properties, thermal or
mechanical treatments (cold-hammering, drawing,
laminating, extruding, etc...) which cannot
be applied to a binder eitller before mixing because
such mixing would no longer be possible, or after
mixing because then it is no longer accessible
within the mixture.
A alethod is also kno~l for givin~ a
better mechanical performance to a mass of ground.
This process consists in incorporating to the soil,
elements which withstand well to pulling forces and
constitute reinforcements, in electroplated steel,
aluminium alloy or in chromium-containing stainless
~teel. Said reinforcements are in the form of tapes,
120 mm wide, or of grids, etc... Owing to these
reinforcements, the particles of soil are joined
together by the soil-reinforcements contact. The
material reinforced according to this techrlique
shows the qualities of a powdered material and a
strength ~Yhich is directly proportional to the
tensile strensth of the reinforcements.
The incorporation of these reinforcing elem-
ents to grounds can only be effected on thc
utilization site. The successive layers of ground
should be levelled, then the reinforcing elements have
to be suitably arranged on the surface of each
layer. This work requires much halldling and should
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be effected with enough accuracy if one wants to
obtain a regular distribwtion and a specific
proportion of elements of reinforcement.
ln addition, the metallic tapes are
relatively expensive, all the more so that they need
to be made of corrosion-resisting metals. The ageing
factor with such metals also has to be considered.
This reinforced ground is not therefore
very widely used because of its price and of the
experienced labour required for its production
on the actual site, since it is not transportable.
An object of an aspect of the present invention is
to overcome these disadvantages and to propose
a material with a good mechanical strength and able to
be produced by a simple and reasonably cheap method.
This object is reached according to the
invention due to the fact that the n~aterial comprises
at least one continuous linear element which is
flexible - or supple - and distributed tri-dimension-
ally, at random, in a mass of solid particles ofcompact form, so that it contributes to creating a
certain cohesion between the different parts of the
mass of particles.
Advantageously, the continuous element
is distrlbuted substantially evenly in the mass
of particles, and the latter are advantaseously
jointed togeth~r.
,~dvantageously, its content, by weight,
of particles is greater than that of the cor!tinuous
element, said content by weight of continuous element
being preferably varying between a ~ew hundredth and
a few tenths.
Advantageously, the continuous element is
selected from the following elements: yarn comprising
at least one continuous chemical strand, textile yarn
21
formed from di~scontinuous fibres, wire, metal tape,
narrow band, fil~:rill.ate blade.
Advantageously, ~he cOntinuous element
constitutes the only binding means between the
5 particles.
As an altcrnative, the rnaterial f~ther
compriseq a bincling agent wllicll contri.butes to
bindirlg together -the continllous element and the
particle.s, and to binding -t]~e particles ~ogetller.
Advantageously-, the ~i.ncling agerlt is
selec-ted from the following products: llydra~llic
binder, hydrocarbon binder, pozzolana bincler added
with lime, chemical binder.
Advantageously, the particles are selected
1.5 from the following types of par-ticles: sand, gravel,
stones, pieces of natural rocks, fragments of
natural soils, artificial aggregates, concrete
blocks, solid domestic or industrial wastes~
The material accorcling to the inven-tion
20 i9 advantageously produced according to the follow-
ing method whereby a flow of fluid is created and a
mass of solid particles of concentrated - or compact -
form are introdu¢ed into said flow to~ether with at
least one flexible - or supple - contimuous linear
element, then the particles and tlle contin-lous
element are mixed together homogelleol1sly and collect-
ed on a s-lpport and separated from the fl~lid.
Advant~geously, the said flow of fluid
is a flc~w of licl~licl which liquid is removc-d when
the constiluer-~s of` the said mixt~e are collected
on the .support.
Said metllod is advantageously performed
in an installation which, according to the
invention, comprises means for creatins a flow of
fluid, means for supplying the said continuous element,
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means for bringing the said element into the said flow
of fluid, means for gradually mixing up the said fluid,
the said continuous element and a certain proportion
of the said mass of particles, and means for removing
the fluid from the said mixture.
An aspect of the invention is as follows:
Apparatus for producing a building material, which
building material comprises flexible tri-dimensional
reinforcement disposed in a mass of solid particles of
compact form and contributing to creating a certain
cohesion between the different parts of the mass of
particles, wherein said reinforcement comprises at least
a flexible, continuous, linear element distributed tri-
dimensionally, in random manner, within said mass of
particles and creating said cohesion by entwining said
parts of said mass of particles, said apparatus
comprising means for creating a flow of fluid, means
for supplying the said continuous element, means for
bringing the said continuous element into the flow of
fluid, means for mixing progressively the said fluid,
the said continuous element and a certain proportion of
the said mass of particles, and means for draining the
fluid from the said mixture.
~9~1
-6a-
The invention will be more readily under-
stood on reading the follol~ing description of several
embodiments with reference to the accompanying
~rawinss in wllich:
- Fi.gure 1 is a diagrammatical elevation
of a first embodiment of an installati.on for producing
the material according to the invention;
- E~igure 2 is a diagrammatical elevation of
a second embodiment of an instal.lation for producing
the material according to the invention;
- Figl~e ~ is a partial diagrammatical
elevation of a third embodiment of an installation
for producing the material according to the invention;
- Figure 4 is a partial diagrammatical
elevation of a fourth embodiment of an installation
forproducing the material according to the invention;
- ~igure 5 is a partial diagrammatical
elevation of a fifth embodiment of an installation
for producing the material according to the
invention;
- Fig~u-e 6 is a par-tial diagralll of` a sixth
embodimen-t of an installation for producing the
material according to the invelltion.
Thus the material according to the invention
is consti.tuted of a random mixture of particles of
concentra-ted - or compact - form and of wires or
yarns or continuous flexible tapes and/or their
combinations.
Advantageously the particles are rigid.
Advantageously the parti.cles constitute
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the largest part of the ma-terial in weight pro-
portion. Particles of a different nature or orisin
may be added to the material. Amongst swi~able ones,
can be cited:
- natural mineral particles such as sand,
gravel, stones, pieces of natural rocks, fine soils,
etc...;
- natural mineral particles, treated (by
crushing, sur~`ace treatments, etc...) and/or
selected by screening, sifting, sedimentation or any
other selecting means, forming a mixture of con-trolled
grading composition and -the properties (shape, surface
characteris~ics, etc...) whose particle3 have been
improved;
- reconstituted mirleral particles: concrete
blocks, artificial a~sgrega-te composed of sand and
slack bonded together with a binder, arti~icial
mineral agsre~ate of all natures such as expanded
clay, expanded schist, etc..., which particles come
from the grinding, by any method, o~ a concrete or
of any other type of bonded material such as ~ravel
or sand cement gravel or sand bitumen, gravel or slag
sand, etc...;
- particles, whether mineral or not, of
industrial origjn.
The gradin~s of the partlcles constituting
the material may be e~tremely varied, both in ma~imum
or average sizes of the particles and in the
graded distribu-tion, depending on the intended object
and/or on the conditions o~ production.
The wires, yarns, small laminae (or srnall
bands) or fibrillate strips which constitute the main
component of the material object of the invention
are continuous elements. Within the scope of the
invention, tlle terrn "continuous" sllould be interpreted
in the way it is normally interpreted
6;~1
in the textile industry, name:Ly thclt -the elemerlts
used are of great length wi-th respect ~o fibres
of natural origin (whose length is norrnally only a
few centimetres), or with respect to cut chemical
fibres such as those are used in industry.
The above-mentioned continuous wires,
yarns, tapes, small bands can be produced inmlediately
before beins mixed with the particles, OI' they can
be produced industrially and re-used for tl~s mixing
10 under an appropriate form treels, skeins, etc),
The nature of the wires, yarns, tapes or
~mall bands -used in the material needs to be such
that their mecllanical properties are good enougll
for the final material to give a good mechanical
performance.
In the case Or yarns, the nature of -the
fibres or strands forming part of them can be varied:
animal or vegetable natural fibres, chemical and/or
metallic filalnent of fibres.
The yarns~ small bands or fibrillate
laminae can be of chemical and/or metallic nature.
All the continuous wires, yarns, tapes, small
bands and fibrillate laminae and their combinations~
will be desi~nated hereinafter as continuous elements.
The proportion by weight of continuous
elements in the material can advantageously Yary
between a low rate value percent and a very low rate
value per ten-thousandth for example.
Different parameters can be used to
describe the material, SUCII as for example:
- parameters describing all tlle particles
(nature, mechanical properties, dimensions, shape,
grading distribution, parameters describing the geom -
e~trical disposition, etc...);
~ - parameters describing the continuous
9~
elements (nature, transverse dintensions, mecharlical
properties, etc...);
- parameters describing the relations
inside the material between thc mass of particles and
the network - or assembly - of continuous *lemell-ts,
and in particular amon$st these:
. the volumeral and weight percentages of
the continuous elements, ~itll reYpect to the particles,
. the avert-lge len~tll L Or the continuous
elements per Ulit of volume of the material,
. the dimension M of the average -theoretical
cubical mesh which would correspond to a tri-dimensional
cubical network of -the same value L,
. the geometrical distribution of the
continuous elements inside the material,
- parameters describing the overall per-
formance of the material in relation to the uses
made of it.
According to another embodiment, the
material according to the lnvention comprises in
addition to the particles and to the continuous
elements, a complementary binder or other additive.
Said binder can be either a hydraulic binder (cement,
lime, etc...), or a hydrocarbon bincler (bitwl1erl,
tar, etc...), or a pozzolana binder adcled ~ith lime
(suitable pozzolana binder are natural pozzolana
or flue dust from heat power sta-tions), or a chemical
binder (resin).
The material obtained accordin~ -to the
invention is constituted by the imbricatioll of a
mass of particles and a tri-dimensional network of
cont illUO US elcments.
The said continuous elements are dls-tributed
- or dlsposed - in disorder inside the mass of
particles; each section - or part - of saicl
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- 10
continuous elements is randomly orientated and
arranged iIl -Che space, the distribution of said
sections being deperlclent on the conditions of
production and of use.
The main part played by the continuous
elc~lents with respect to the mass of particles,
is two-fold. I-t is:
1. To contribute to the mecllallical strength
of the mixture. The mechanical interaction of the
network of continuous elements and of the rnass of
particles is complex. The continuous elemen-ts are
- stretched, when deformations occur in tlle nlass of
particles, by different mechanisms, amongst ~Yhich :
the friction between the continuous elements and
the particles, the stretchin5 of any loops formed by
the continuous elements inside the mass of particles,
the interlacing of the continuous elements, which
limits the possibilities of movement of the continuous
elements inside the mass of particles. The tensile
strensttl of the continuous elements then opposes the
deformations of the material. The great length of the
continuous elements largely contributes to these
mechanisms appearing and as a result plays a great
part in the overall strength of the material to
whicll participates a mass of material which is all
the greater tha~ the very long continuous elements
transmit the `orces very far from the area initially
acted upon.
2. To improve the resistance to internal or
external erosion of the mass of particles, following
the imbrication of the particles inside the network
of continllous elements, in particular ~Yith respect
to erosion due to water running or infiltratin5.
The resistance to érosion will improve all the
more that the ratio of M to the average di~snsion
z~
of the particlcs is small.
The material obtained according to the
invention shows a number of basic proper-ties which,
for many applications, have considerable advantages
compared with currently available materials.
1. The material constituting the continuous
elements (wires, yarns, tapes, small bands and
their combinatiolls) is used in a form wllich is much
more efficiellt , for equal quant]ty, thall a bulk
binder, to resist the pulling forces occurring
inside the mass of particles sub jected to stresses.
The continuous elements can indeed be produced by
an industrial process capable of developing the
potential mechanical properties of the material
composing them; for example they can be subjected
to a controlled drawing sui-table for obtaining opti-
mum mechanical properties, such as tensile strength
for example.
2. The use of the mater:ial constituting
the continuous elements in the form of wires, yarns,
tapes, small bands, or fibrillate strips and/or
their combinations permits an efficient transmission
of the forces inside the material whilst occupying
only a very small fraction of the ernpty spaces in
the granular mass. This gives a number of great
advantages; for example:
a) it is possible to use a much lower
proportion hy weight or volume of the material
constituting the continuous elelnents with respect
to the wllole material than in the case of a bulk
binder, to obtain the same mechanical rcsult;
b) it is possible to obtain a material of
quality with a mass of particles of so-called hollow
or discontinuous grading, - i.e. of a grading allowing
a very high proportion of empty spaces -, whereas
such a result is very difficult to obtain with a
~ ~19~21
12
bullc binder without correcting the gr~dins. This
advantage i5 especially irnportant to improve the
available material of which the grading is
unsui.tabl.e for treatments with a bulk binder;
5 c) since the empty spaces in the mass of
particles are not filled with a mortar or a binder,
it is possible to obtai.n a material with altogether
a high perrneability, a sood mechanical resistance
an(1 a soocl resistance to erosion; th.i~ result i~
particularly advantageous for many applicntions
in which the hydraulic conductivity of tha material
s a factor of major importance;
d) since the empty spaces in the mass of
particles are not filled wi.th mortar, it is possible
to obtain a material which has both a low heat
conductivity and good mechanical resistance;
e) for the same reason, it is possible
to obtain a material with a low density and a good
mechanical strength.
3. From a mechanical standpoint, it is
possible to produce materials which are both strong
and of controllable deformability by a judicious
selection of the material constitutinS the
continuouq elements, of the proportion o~ the
2~ continuous elemerlts used ir~ the rnass of particles
and their seometrical distribution therein. Now,
it is important, when plarming a work, to be
able to choose materials of required deformability,
neither too low nor too high, in order to solve
the problems of distribution of stresses between
~ifferent elements of a product or between the
~round and the product. The materials bonded with
bulk binders are often either excessively rigid
or prone to cre~PinS
4. The stresses inqide the material accord-
.~ti~ 621
13
ing to the invention are di~ided and transmitted
in two complementary and more or less independent
ways occurring respectively in each of two dimension-
al ranges of the material: these stresses are
tran~mitted on the one hand, from one particle to
another inside the mass of particle, on the other
hand, throu~h the networlc of continuous elements.
The complementary nature of these two transmission
modes affords a compe~lsation of the 1OCA1 heterOgeneit-
ies and, as a re~ult, a better overall mechanic~lhomogeneity; for example, a localized weakness
(compressibility, fragility, etc...) of one or more
particles will not constitute a defect which can be
at the origin of a breaking process.
The conditions in which a material has been
produced are siven hereunder, by way of e~ample:
- particle : sand of grading 0.2 to 2 mm;
- continuous element : untwisted yarn of
- 17 te~ formed ~y l~6 strands of polyester;
- percentase by weight of yarn with respect
to the sand: 0.14 per cent;
- L = 0.125 m/cm3;
- M = 4.9 mm.
The yarn is incorporated to the sand as
follows (see Figure 1):
- the sand 1 is brought in at a controlled
rate by an endless belt 2;
- the sand 1 falls into the hopper 3 where
it is carried a~ay with water sprayed in 4 by a
nozzle or spreader jet 5;
- ~der the hopper 3, a constant flow of
water and sand 6 is created, the form and speed of
which are controlled;
- a pneumatic delivery gun 7 projects, towards
the flow G a yarn 8 which comes from a reel 9;
,
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l4
the yarl~/sancl do~a$e is l;hUS co~trolled
by tlle colltrol of the flow o~ salld ~nd ~ c speed of`
projection o~ t~le yarn ~;
_ t]lO sallcl I yarn ~ water mixture settLes
on a support lO, in layers successi~ely covering
one another progressively with the flol~, whilst
the water is drained naturally by gravity for
example towards the outlets lOa Or the support lO.
T]le material produced t]liS way has a dry
density Or about 1.5 g/cm3. Placed in a containe~
of low rigidity (PVC) and subjected, at that density,
to a punching test using a circular punch of 50 mm
diameter, the force needed for driving in punches
of l mm is ~proximately l ton, this corresponding
to approximately 50 kg/cm2, pressure without common
measure with the punching pressure of the same sand
containing no yarns and placed at the same density.
The material according to the invention
finds a special application in building and civil
engineering (including agricultural engineering,
etc...).
Amongst possible applications for the
material according to the invention, the following
one is given by way of example and non-restrictively.
This application is illustrated in l~igure 2 and cons-
ists in the inexpensive production of a road on a
sandy ground, unsuited, in its natural state, to
receive vehicles. The work is effected on a natural
ground composed of clean sand of grading : 0.2 to
l mm when dry.
A super~icial layer ll of the sand of
the laid-out track is removed by means of a loading
excavator 12 which supplies a conveyor belt 13;
said latter, which is situated in parallel to -the
lay-out of the track, is meant to drop the sand
9 ~ ~1
back on the tracls lay-out via a hydraulic cyclone -
or hopper 1~ -. The form and rate of the flow of sand
and water 15 permit to resettle the sand regularly
over the track lay-out. ~hilst the sand is dropping
; on to the ground, yarns 17, supplied from a reel
90, are projected pneumatically by a device 70 on to
the sand and is incorporated therein. These yarns
are polyester yarns of 40 decitex, in the proportion
of 0.1% by weigllt of the sand.
In view o~ the width of the machine which
is 2 metres, the operation is repeated over several
parallelchannels the number of which is dependent
on the width proposed for the track. Another solution
consists in producin$ the material in a specific
place and in transportinS and spreading it.
The assembly of layers 16 deposited on the
ground, is then compacted and covered with a super-
ficial coating uhich will be described hereinafter.
If it is considered advantageous for the
fastening o.~ the superficial coating (and this is
dependent on the type of vehicles called upon to
travel on the road), the yarn
projection method can be controlled so that the
density of the yarns 17 on the surface of the layer
16 is higher than anywhere else in the thickness of
the layer.
The superficial coating is produced as follows:
An emulsion of bitumen of 0.5 l/m2 is
spread, then a non-woven textile sheet of 150 g/m2,
is laid thereon, the latter adhering to the subjacent
layer by way of bitumen and yarns, ~hich joins it to the
mass. A second layer of emulsion and a layer of gravel
complete the superficial coating.
In the aforesaid application, thee~uivalent
theoretical cubic mesh M has a value of 2.1 mm and
,C~
16
the lensth of tl~e yarn per unit of volw
o.6~ 111/C1113.
A common rolling f`rame 18, whlcl~ may be
automo~ive, supports the endless belt 13, tlle
; excavator 12 and if necessary the elements 14, 70
and 90.
Another application of tlle material describ-
ed herei.nabove is the producti.on of a f`o~uldation mass
for oil drilling worl~s at sea.
A coarse sand of 1 to 3 mm grad.i.ng is
dredged on a suitable site and transported by barges
on the working site. Said sand is picked up by
hydraulic means and polyamide yarns of 100 decitex are
incorporated to the sand by direct hydraulic drive
means.
The dosage by weight of the yarns is of
0.2/o of the weight of the sand (M = 3 mnl). The sand
+ yarns mixture is deposited on the sea bed to
progressively constitute a fo~mdation mass which
resists erosion during the making up phase and
l~hiCIl S}IOWS goo(l mechanical properties. A final
external protection is given by depositi.ng, using
the same method, a coarser divided material, of
between 5 and 10 mm grading, the yarns bcing yarns
f 150 decitex, in the proportion. by weight of` 0.3%
by weight of the divided material (M=3mm).
Other possible applications of the
material according to the invention:
- superficial layer to protec-t a sandy
area (such as a desertic area) against ~Yind erosion.
- light and insulating material.s
constituted by the material obtained accordins to
the invention T~herein the particles are lightweight
aggregates (expanded clay for example);
- draining and filtering layer for sur-
facing banks or for cost protection;
96Z~
17
- mass embankment wi-th a steeper slope than
would allow the particles used Wit]lOUt continuous
elements;
- mass embankment resisting to erosion;
- surfacing material resisting to erosion;
- substratum of a concrete road;
- substratum for railway lines.
Figure 3 shows a conveyor belt 19 supplying
the granular material 20, and associated to a flow
regulating device constituted by a scraper 21
extending crosswise above the belt 19 at an adjustable
distance whicll is dependent upon the desired rate of
flow. Said belt 19 is driven in the direction of
arrow F by a motor ~. The unloading end of the belt
19 is situated above a hopper 22, cylindro-conical
in shape which is also supplied with water via a
pipe 23 the supply end 23a of which is helical-
shaped so as to communicate a vortex motion to the
water distributed by said pipe. The hopper 22 i~
placed above a receivinS surface 24 advantageously
constituted by a sieve which is provided to allow the
removal of the water from the solid materials.
A device for supplying filiforlll reinforcem-
ent elements, such as for example a t0xti1e or
plastic yarn 25 of indefinite 10llSth is provided
on the outside of the llopper. Said supply device
comprises a 9uppl~ reel, a pair of drivins rollers
9 for driving the yarn 25 and a compressed air gun
27 for suidin~s the yarn towards the whirling mixture
of sand and water~ coming out of ~h~ hopper 22.
The method carried out with the lnstallation
according to the invention consists in pouring a
predetermined quantity of granular material 20 in the
hopper 22 inside which hopper is immediately created
a vortex of water 29 which mixes with the granular
material and carries it in its whirling motion.
.,
96Zl
lo
At the outlet of the hopper 22, the water and the
granular material form a tubular flow 30 which,
under the effect of tangential force, flares out in
descent as a sort of sheet of sludge twirling
turbulently. It is in that part of the flow that
the yarn is brought by reels 27 which fix the supply
of -the yarn and by the gun 28 which, in its jet of
compressed air, guides the yarn 25 into the mixture
of granular material and liquid 30. The liquid takes
the yarn into its whirling motion directins it towards
the receiving surface 6 where tlle said yarn mixes
with the sranular material as the latter settles,
whereas the water is evacuated through the holes 24a
provided in the receivinS surface 24. The yarn
25 could, as in the case of Figure 2, be incorporated
to the flow of water and sand in tlle hopper 22. It
is also possible to simultaneously incorporate several
yarns, either in one single part, or indifferent
parts of the flow of liquid.
The device sho~1 in Figure 4 uses a double
ejector. Such device comprises a nozzle 31,
connected to a source of pressurized water not shown.
The nozzle 31 issues into a pipe 32 connected
laterally via a pipe 32a to a source of filiform
element 33. The pipe 32 narrows towards tho base anfl
issues into a larger pipe 34 which commurlicates later-
ally with a source of sand 35; sai~ latter can be
supplied by means similar to those sho~ in Figure 1
for example.
The depression created in the pipe 32 at
the outlet of the nozzle 31 sucks in the yarn
of the reel 33, which yarn is carried wi-th the
water t]lrough the pipe 32. The depression created
in thepipe 34 at the outlet of tlle pipe 32 sucks in
the sand from tlle source 35. Such a de~ice should work
9~
19
with a dry sand or else, means sl-ould be provided
to prevent the sand from clogging up between the
reserve of sand 35 and the pipe 34.
Figur~ 5 si~ows a variant embodiment Wit}l
one ejector, which comprises a nozzle 36, into wl~ich
issues a pipe 37 for guiding a yarn 37a. Said nozzle
36 issues into a pipe 38 which communicates laterally
via a conduit 3~a with a tank 39 containing a mixture
of sand and water stirred by an agitator ~10.
The water is brought under pressure into
the nozzle 36 and creates a depression at the outlet
36a of the nozzle, which depression sucl~s in the
mixture o~ water and sand of the tank 39 together
with the reinforcing yarn 37a in order to deposit the
said mixture on to a support, not shown, wherefrom
the water is drained off.
~ inally, ~igure 6 shows another variant
embodiment comprising one ejector 41 connected to a
source of pressurized water via a lateral pipe 42
and to a reel of yarn 43 via a pipe 44. The yarn
43a carried by the depression created by the water
flow at the level of the outlet 44a of the pipe 44,
is directed with the spray of water 45 sent by the
ejector 41 into a layer of granular material 46.
The pressure of the spray of water causes the liquid
to penetrate the layer 46 to a certain dep~h which
depth is dependent upon the pressure and the said
liquid carries the yarn into the said layer wilst
mixing it witl~ the sand. A relative movement between
the spray of water and the layer of sand ensures the
distribution of the yarn.
