Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION:
METHOD OF ASSEMBLY OF MODULAR
RESERVOIR WITH INTEGRAL COMPRESSIBLE SEALING STRIPS AND
EXPANSION JOINT
BACKGROUND OF THE INVENTION
It is known to provide an assembly of extruded thermoplastic structural
components for use in the construction of the upright side walls of a modular
building, for example
schools, residential buildings, and the like. Each of these structural
components includes an
elongated rigid sheet member having at least two spaced-apart edges and
provided with at least two
integral lengthwise rail members located near corresponding edges thereof, a
few of the structural
components being releasably slidingly interlocked with one another about their
rail members,
without tools being required, to form hollow elongated panels. Each hollow
panel defines a main
body including a flat exterior face and a flat interior face, and
circumscribes a generally closed inner
enclosure cell, the hollow panel releasably interlocking with adjoining hollow
panels successively
to form a continuous wall structure. The structural components include first
and second flat wall
structural components and first and second elbowed corner structural
components, the first elbowed
comer structural component having opposite end edges and an intermediate
corner edge and being
provided with at least three spaced-apart integral lengthwise rail members
located near the
respective end and intermediate edges thereof. The inner cell is destined to
receive concrete to be
poured therein and the hollow panel body is adapted to withstand the load of a
column of concrete
poured therein. The position of one of the structural component relative to
the other adjacent
structural components is slidingly adjustable along the rail members.
However, such known extruded thermoplastic structural components are not as
effective for the manufacture of water tanks, since there remains a vertical
gap within the hinge
formed between each pair of successive structural components. Contaminants
such as bacteriae
and fungus may build up within this hinge, thus possibly compromising the
potable quality of water
inside the tank. Unfortunately, this gap between the extruded thermoplastic
structural components
is required to enable the assembly thereof. Indeed, the usual method of
assembly of extruded
thermoplastic structural components is to vertically interlock each successive
pair of such structural
components by slidingly engaging same at their meeting comer portions. It is
not currently possible
to efficiently generate thermoplastic walls being totally smooth and without
any gap between each
successive pair of such structural components.
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Moreover, the joints between structural components may not prevent accidental
water leakage from the water tank into the radially outward concrete walls
that support the water
tank, which could reduce the useful life time of this supporting concrete
structure. The water tanks
should be water-tight, and the plurality of sealing joints between the
structural components means
that it is not cost-effective to individually seal all these joints once the
tank structure has been set.
SUMMARY OF THE INVENTION
The invention relates to an assembly of extruded structural modular wall
components for use in the construction of the upright side walls of a water
tank, each of said wall
components including an elongated rigid sheet member having two integral
lengthwise rail
members located near corresponding opposite edges thereof, said wall
components being releasably
slidingly interlocked with one another about their rail members at hinge means
to form hollow
elongated panels; each hollow panel defining a main body including a flat
inner exposed surface,
for direct engagement with the water inside the water tank, and an opposite
outer formwork area,
for receiving liquid concrete to be cured, a hollow panel releasably
interlocking with adjoining
hollow panels successively to form a substantially continuous wall structure
circumscribing a
generally closed water receiving enclosure; and further including first seal
barrier means, mounted
into each hinge means; wherein said first seal barrier means defines an
inoperative condition, and
an operative condition where both structural integrity and waterproofness of
the water tank are
achieved.
Preferably, a second seal barrier means is mounted about said hinge means
adjacent
each said wall component inner exposed surface spacedly from said first seal
barrier means, said
first and second seal barrier means for direct liquid engagement with the
water tank water; wherein
said second seal barrier means cooperates with said hinge means to provide a
continuous wall
structure when said hollow panels are interlocked with one another in
successive pairs.
A biocide agent could be integrated with said second seal barrier means,
wherein
contamination of the water tank water is mitigated. Preferably, said biocide
agent is selected from
the group comprising Phenoxarsine 0, Fungitrol and Nuocide (the latter two
being made by
International Specialty Products, New Jersey, USA) at a concentration
preferably less than 0,1 %
by weight of the total weight of said second seal barrier means.
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In one embodiment, said hinge means includes a male rail element from a first
said
modular wall component, and a female rail element from a second said
successive modular wall
component, said first seal barrier means mounted inside a cavity defined by
said female rail
element.
Preferably, said first seal barrier means is an expansible joint, engaged into
and
occupying a small fraction of said female rail element cavity in said
inoperative condition thereof,
but completely filling up said female rail element cavity in said operative
condition thereof; said
second seal barrier means being less effective in waterproofness than said
first seal barrier means so
that water being filled into the water tank is allowed to seep partly around
said second seal barrier
means and reach said first seal barrier means. In said operative condition of
said expansible joint,
said male element could wedge a leading edge portion thereof being exposed to
the water from the
water tank water exclusively from the remainder of said expansible joint, said
expansible joint
leading edge portion being small relative to the overall volume of said
expansible joint.
Preferably, said expansion joint is made from at least one organic ingredient
and
from an inorganic ingredient. Said organic ingredient could comprise a
hydrophilic resin. Said
hydrophilic resin could be selected from the group comprising polyacrylamide,
acrylic polymer and
polyurethane foam. Said organic ingredient could also further comprises a
thermoplastic rubber
compound, preferably selected from the group comprising ethylene propylene
diene, chloroprene,
and polyisoprene. Said inorganic ingredient could be a filler selected from
the group comprising
calcium carbonate, calcium chloride, silicium dioxide and bentonite.
In one embodiment, said second seal barrier means forms a sealing strip having
a
hardness value ranging between 45 and 65 on the SHORE D scale, while said
modular wall
components have a hardness value ranging between 75 to 85 on the SHORE D
scale, said second
seal barrier means sealing strip being added by coextrusion to the corner
portion of each modular
wall components. Said second seal barrier means could provide redundancy to
the sealing features
of the first seal barrier means, for example if the first seal barrier means
becomes accidentally
damaged during erection of the water tank and associated seal barrier means.
The invention also relates to a method of assembly of a water tank of the type
where the water tank comprises a number of peripherally disposed modular wall
components, each
modular wall component defining a radially inner exposed surface, for direct
engagement with the
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water inside the water tank, and a radially outer formwork area, opposite said
inner exposed
surface, for receiving liquid concrete to be cured, hinge means edgewisely
interlocking each pair of
successive said modular wall components, and first seal barrier means, mounted
into each said
hinge means; wherein said first seal barrier means cooperates with said hinge
means so as to
releasably interlock said modular wall components in their peripherally
disposed fashion, said first
seal barrier means defining an inoperative condition, and an operative
condition where both
structural integrity and waterproofness of the water tank are achieved;
wherein said first seal barrier
means is an expansible joint, engaged into and occupying a small fraction of
said female element
cavity in said inoperative condition thereof, but completely filling up said
female element cavity in
said operative condition thereof; said second seal barrier means being less
effective than said first
seal barrier means so that water from said tank is allowed to seep partly
around said second seal
barrier means and reach said first seal barrier means; the method comprising
the following steps:
inserting said expansible joint into said hinge means; tilting each pair of
successive first and second
said wall components relative to one another by a small acute angle
(preferably of between 15 to 25
degrees), vertically sliding facing edge portions of said each pair of first
and second wall
components about said hinge means; tilting back said first and second wall
components to a
coextensive substantially planar condition; filling up water inside the water
tank, wherein said
expansible joint comes to be soaked with water; and allowing water to expand
said expansible joint,
until a completely water tight hinge means is achieved.
The method could also be such that a second seal barrier means would be added,
forming a deformable non expansible bevelled joint, the latter joint forming
an exposed slanted
edge surface, wherein the method further comprises the additional following
steps of: before said
step a), inserting said bevelled joint into said hinge means, and fixedly
securing said bevelled joint
against said hinge means radially inwardly of said expansible joint; and
between steps d) and e)
cushioning this tilting back step by cooperative action of deforming motion of
said bevelled joint
about its slanted edge surface.
Preferably, the method also includes a step between steps a) and b) of fixedly
securing said first expansible joint to corresponding wall components within
said hinge means,
wherein said expansible joint securing means is selected from the group
comprising friction fit
interlock with said wall component within said cavity, coextrusion during
manfacture thereof, and
application of a glue compound fixedly interconnecting said expansible joint
to said wall
component within said cavity. The expansible compound could also be applied by
a caulking gun
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("gunning").
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a top edge plan view of a number of prior art upright rigid
thermoplastic structural
components forming a fraction of the side walls of an upright upstanding wall;
Figure 2 is a top edge plan view of one rigid L-shape structural component
similar to those of figure
1, and further showing a soft thermoplastic bevelled seal joint made by
coextrusion along an interior
corner thereof;
Figure 3 is an enlarged view of the corner portion of figure 2, and further
showing the expansible
seal joint;
Figures 4 and 5 are top edge plan view of a pair of interlocking L-shape
structural components of
figure 2, showing the two seal joints of figure 3, and sequentially suggesting
how these two
structural wall components become interlocked in fluid tight fashion;
Figure 6, on the third sheet of drawings, is an enlarged view of the partly
interlocked portion of the
pair of L-shape structural components of figure 4;
Figure 7, on the second sheet of drawings, is an enlarged view of the fully
interlocked portion of
the pair of L-shape structural components of figure 5;
Figure 8 is a perspective view, at a smaller scale, of the expansible seal
joint of figure 3;
Figure 9, on the last sheet of drawings, is a view similar to figure 3, but
with the expansible seal
joint in friction fit interlock with the PVC structural component;
Figure 10 is a view similar to figure 9, but with the expansible seal joint
being fixedly secured by a
glue component to the PVC structural component; and
Figure 11 is a partly broken plan view of a PVC structural component, clearly
showing that the
expansible seal joint is a single monolithic "stick" extending along the full
length of the PVC
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structural component.
DETAILED DESCRIPTION OF THE EMBODIMENT OF THE INVENTION
The present invention is therefore directed to improving upon existing
assemblies
of extruded thermoplastic structural components for modular reservoir
constructions, and in
particular for potable water tank applications and for pisciculture (for
example, for salmon farms).
Figure 1 shows a prior art section of upright wall assembly 10, made of two L-
shape
extruded PVC structural components 12, 14 interlocked with flat extruded PVC
structural
components 16, 18. L-shape component 12 includes a first wall 20 and a second
wall 22 generally
perpendicular to one another, while L-shape component 14 similarly has a first
wall 24 and a
second wall 26 generally perpendicular to one another. The exterior PVC layer
face 20A, 24A of
each walls 20, 24, respectively typically includes a higher quality PVC
material, and is adapted to
be the exposed face at the interior of a water tank T. Each outer end of L-
shape legs 22, 26, form a
rail member 28, 30, respectively, of a design enabling transverse interlock of
two opposite exterior
legs 16, 18. The opposite ends of L-shape legs 22, 24, form elbowed lips 32,
34, respectively, and
the intermediate section of legs 22, 24, form rail members 36, 38,
respectively, of a design enabling
transverse interlock of one lip 34 from one L-shape component 14 with one rail
member 36 from
another L-shape component 12. The free end tip 32A, 34A, of each lip 32, 34,
is also bevelled.
Accordingly, an interior gap 40 remains between interlocked lip 34 and
adjacent leg 36A from rail
member 36, with gap 40 facing the interior of water tank T. A fluid passageway
41 is formed
between interior gap 40 and the formwork cell C opposite the interior of water
tank T. Panels 16,
18, each include at opposite ends elbowed lips 42, 44, and 46, 48,
respectively, which are similar to
lips 32, 34 but inverted relative thereto. Each pair of registering lips of
panels 16, 18, say lips 44,
48, are able to interlock with complementary sections of L-shape outer end
rail member, say rail
member 28.
In figures 2 and 3, there is shown an L-shape structural component 12, with a
radially
inwardly located soft sealing strip 50 being added to the exposed surface of
leg 36A of rail member
36. Soft sealing strip 50 is preferably PVC, and strip 50 is factory installed
to leg 36A by co-
extrusion process. As best shown in figure 3, PVC strip 50 includes an exposed
outer surface 50A
which is bevelled, i.e. that PVC strip 50 has a thicker portion adjacent
interior surface wall layer
20A of panel 20, which progressively becomes thinner as one moves away from
surface layer 20A.
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PVC strip 50 should extend for a large fraction of and not excluding all of
the height of upright leg
section 36A of upright L-shape component 12.
Two different levels of hardness are used for manufacture of the thermoplastic
(preferably polyvinyl chloride or PVC as it is cheaper and easier to handle)
components of the
present invention: the standard "rigid" hardness level for most of the PVC
component, preferably
varying between 75 and 85 on the SHORE D scale, and being most preferably of a
hardness value
of about 79 on the SHORE D scale and a lower "flexible" hardness level,
preferably varying
between 45 and 65 on the SHORE A scale, and being most preferably of a
hardness value of about
55 on the SHORE A scale, for a radially inward sealing strip 50 (detailed
hereinbelow) added by
coextrus ion to the corner portion of each L-shape extruded PVC structural
component 12. (For
context purposes only, a residential window frame is made of rigid PVC, while
the flexible sealing
lips between this window frame and the corresponding window glass are made
from flexible PVC)
The purpose of this radially inward sealing strip 50 is to therefore seal the
above-noted gap between
two above-noted successive structural components, to prevent passage of
microbial contaminants
such as bacteriae, fungus or mold, without hampering ease of assembly of the
PVC structural
components to form a modular wall construction.
PVC strip 50 has memory shape, i.e. it will hold its own bevelled shape in
unbiased
condition, but will be able to deform under compressing force, such as when
elbowed lip 34
engages with leg 36A as suggested in figure 7 and is tilted thereagainst. In
figure 7, it can be seen
that the shape of sealing strip 50 has changed from bevelled to generally
ovoidal, and that the gap
40 facing the interior of the water tank T has been closed in partly fluid-
tight fashion. However,
passageway 41 still opens freely at the opposite end into formwork cell C.
Seal strip 50 should
extend the full height of the modular wall component 12.
The size of unbiased bevelled soft PVC strip 50 should be such that the
thicker
section thereof is slightly wider than the width value of gap 40, and that the
thinner section thereof
is slightly narrower than this width value of gap 40, so that upon deformation
of PVC strip 50 under
biasing load from engagement of leg 36A of rail member 36 into the hollow of
elbowed lip 34,
(figure 7) a partly water-tight sealing interengagement is achieved between
leg 36A and lip 34 via
soft PVC strip 50 closing gap 40.
Preferably, a biocide agent effective against at least bacteriae and/or
fungus, is
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factory admixed with the compound of expansion joint 49. This biocide agent
could be for example
Phenoxarsine 0, Fungitrol 0 or Nuocide , but in those cases, should be at a
very low
concentration, preferably less than 0,1 % in weight as of total weight of the
expansion joint 49, in
view of chemical toxicity issues for the marine life inside water tank T.
Accordingly, no
microbiological contaminant is allowed to enter gap 40 before water fills
water tank T. Radially
inwardly located sealing strip 50 being in constant direct contact with water
from the tank T when
the latter is filled up with water, strip 50 cannot and does not incorporate a
biocide agent in view of
the above-noted chemical toxicity issues that may arise with the fish inside
the water tank T. On the
other hand, although expansion joint 49 in unexpanded state comes initially in
contact with the
water from the water tank T, once joint 49 achieves its fully expanded
operative condition due to
water from water tank T soaking same during its expansion, radially outward
joint 49 becomes
substantially shielded from water coming from water tank T by radially inward
sealing strip 50, so
that on a long term continuous basis after full expansion of expansion joint
49, chemical leaching of
biocide agent from radially outward expansion joint 49 in a direction radially
inward toward the
water of water tank T will be substantially prevented by radially inward
sealing joint 50.
Preferably, the interior face layer 20A, 24A, of legs 20, 24, could be of
higher
quality rigid PVC, while the remainder of components 12, 14, 16 and 18 (except
soft PVC strip 50)
could be made of lower quality (e.g. made from recycled material) rigid PVC.
Figures 4 to 6 shows that, contrary to conventional interengagement of each
successive pair
of PVC components, where rail member 36 and elbowed lip 34 are interlocked in
sliding motion
with panel 22 remaining perpendicular to legs 20 and 24 during the sliding
motion, in the present
invention, panel 22 must be first be tilted by a small acute angle, preferably
ranging between 15 and
25 degrees, and most preferably of about 20 degrees, before vertical sliding
motion is performed, to
accommodate free passage of added strip 50. This tilted sliding motion is
facilitated by the
bevelling of slanted edge of lip tip 34A. Once rail member 36 and panel lip 34
are fully inserted
into one another, then panel 22 is tilted back to its final condition
perpendicular to panels 20 and 24,
as illustrated in figure 5. It is only after panel 22 has reached its position
orthogonal to panels 20
and 24 that outer panels 16 and 18 (opposite water tank T) can be interlocked
to transverse rail
member 28 at end lips 44 and 48 thereof. At this stage, passageway 41 is not
sealed at its end
opening into formwork cell C (into which fluid concrete will be poured for
water tank support).
Also, sealing strip 50 could optionally provide some level of thermal
adjustment, so
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as to act as an expansion joint in climates where there are substantial
fluctuations between night and
day, wherein cyclical dilatation and retraction of the sealing joint 50 would
be accommodated.
As shown in figures 3 to 10 of the drawings, expansion joint 49 is further
added to
provide a complete water tight seal into cavity 51. Expansion joint 49 is
radially outwardly located
relative to radially inward seal joint 50 and spacedly therefrom. Expansion
joint 49 is made from at
least an organic ingredient and an inorganic ingredient. Preferably, the
organic ingredient
comprises a hydrophilic resin, selected from the group comprising
polyacrylamide, acrylic polymer
and polyurethane foam; and/or a thermoplastic rubber compound, selected from
the group
comprising ethylene propylene diene, chloroprene, and polyisoprene. Preferably
also, the inorganic
ingredient will be a filler selected from the group comprising calcium
carbonate, calcium chloride,
silici um dioxide and bentonite.
Examples of such expansible seal joints 49 include:
- the CCW MiraSTOP TM seal from Carlisle Coatings & waterproofing (Wylie,
Texas);
- the Hydrotite TM seal distributed by Greenstreak (St-Louis, Missouri);
- the Swellseal TM distributed by Construction Chemicals inc. (Houston,
Texas);
- the SikaSweel-A TM seal from Sika Canada inc. (Mississauga, Ontario,
Canada), and
manufactured in Europe;
- the HydroSeal HW-0520 TM from Specton Construction products ltd (Acton,
Ontario,
Canada), and manufactured in the United States;
- the Idrostop, manufactured by Mapei in Italy.
Expansible joint 49 is installed into cavity 51 either at the factory, or in
situ where
the water tank is to be mounted. When this joint 49 comes in contact with
water, in particular when
water is filling up inside the water tank T, the joint 49 will expand by
between 100 % and up to 800
%, so as to completely fill the cavity 51 (with lip 34A engaged inside cavity
51, see fig 7) and thus
provide a completely water tight assembly for the water tank T. Once water
fills up water tank T,
expansion joint 49 will come in direct contact with this water and will
progressively expand from its
initial unexpanded condition (fig 3 e.g.) to its fully expanded condition (fig
7) , typically within a
period ranging between about 24 hours to a few to several days, depending on
the seal make.
Expansible joint 49 will come in direct contact with water from water tank T
since expansible joint
49 extends for the full height of the structural components 20, 24, .., as
well as for the bevelled seal
joint 50, but the latter provides only incomplete water seal.
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According to one embodiment, expansion joint 49 is of the type where
maintenance
of its expansion is conditional upon continuous contact with water; expanded
joint 49 will indeed
progressively retract to its original unexpanded state upon soaking contact
with water being
removed.
The present assembly is made up of several structural components 12, 14, ...
having a width of for example 10 centimeters (cm) , circumscribing a water
tank into which a very
important volumic load of water is found, which must be accommodated for water
sealing purposes.
The present solution is furthermore cost-effective, since the expansible joint
seal 49 can be of small
overall relative size.
The installation of this sealing joint 49 can be done directly on the
manufacturing
line, by engaging this sealing joint 49 into cavity 51 transversely through
cavity access mouth 52
(figure 3), and by maintaining this sealing joint 49 in place inside cavity 51
by appropriate securing
means. According to one embodiment of the invention, shown in figure 9 of the
drawings, this joint
securing means will be a friction fit interlock of unexpanded sealing joint 49
at the opposite edges
53, 53' thereof within cavity 51 with opposite facing seating surfaces 120,
122, of structural
components 20, 22, respectively. Seating surface 122 extends through a plane
opening into cavity
mouth 52. According to an alternate embodiment of the invention, shown in
figure 10, this securing
means will be a glue compound 54 applied against the flooring surface 136
within cavity 51
opposite cavity access mouth 52.
Figure 11 shows that for optimal performance, the expansion joint 49 should
most
preferably be a monolithic tube extending for the full height of the
structural component 20, 24,to
prevent accidental water leakage along its length, which would otherwise be
the case if two or more
separate such joint sticks would be staggered axially in end to end fashion.
Seal joints 49 and SO
both abut at their bottom ends against the top surface of a supporting
concrete ground slab. Another
expansible joint, not shown, will be added between these latter bottom ends
and the concrete ground
slab. This latter another expansible seal joint could be for example the
HydroSeal HW-0520 TM
from Specton Construction products ltd.
It is noted that the tilting action of each pair of structural components 20,
24, ...,
(performed either during on site assembly or in the manufacturing line) of the
modular tank T as
discussed above and sequentially illustrated in figures 4 and 6, is not
hindered by the expansion
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joint 49, since the latter remains unexpanded at this stage and thus readily
allows the leg 34A to
move tiltingly within cavity 51 toward but spacedly from cavity seat 136.
Accordingly, the cross-
sectional surface of joint 49 in its unexpanded initial condition (figures 3
and 9-10) should represent
a small fraction of the total internal area of cavity 51, as illustrated, for
example less than half of this
interior area of cavity 51, so as to enable free vertical sliding motion of
the extruded structural
components 20, 24, .... with one another during assembly. On the other hand,
in the fully expanded
condition of joint 49' (figure 7), the cross-sectional surface of joint 49'
would fill all the internal
area of cavity 51, in such a way as to provide a completely liquid tight seal
between structural
component lip 34 and expanded state joint 49'.
Alternate methods of installation would be either caulking gun application or
by
co-extrusion of the expansion joint 49 during manufacture of the structural
components 20, 24. This
would be very efficient, however it would require substantial overhead costs
as well as frequent
adjustments along the production line.
In operation, with the water tank T being progressively filled with water,
radially
outward unexpanded joint 49 comes in direct liquid contact with water from
water tank seeping
through cavities 40 and 51, and around non completely water-tight radially
inward seal 50, and joint
49 progressively expands reactively with soaking contact with water to
eventually provide 100 %
water tight seal within structural component cavity 51 when fully expanded.
Radially inward joint
50 will typically provide mainly a biocide barrier, rather than an effective
water seal, so that no
bacteria, mold or the like microbiological agent potentially harmful to the
marine life inside the
water tank T will be allowed to be accidentally transferred into the water
tank T. Thus, the fish
and/or other marine life inside the water tank T will be protected by the
first inner seal barrier 50 in
direct contact with the water tank water from any biohazard that could
otherwise have been
accidentally generated, while the second radially outer seal barrier 49
provides the 100 % rquired
water tight seal, to retain water inside the water tank T. Hence, both seals
49 and 50 remain in
liquid contact with the water in the tank T, when the latter is filled with
water.
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