U.S. patent application number 10/312645 was filed with the patent office on 2003-09-11 for concrete wall forming system using fabric.
Invention is credited to Bentz, Herbert Walter, Fearn, Richard N..
Application Number | 20030168575 10/312645 |
Document ID | / |
Family ID | 22791291 |
Filed Date | 2003-09-11 |
United States Patent
Application |
20030168575 |
Kind Code |
A1 |
Fearn, Richard N. ; et
al. |
September 11, 2003 |
Concrete wall forming system using fabric
Abstract
A wall form assembly comprising a substantially rigid surface to
maintain the form assembly in a predetermined orientation and at
least one flexible fabric surface spaced from the rigid surface.
The rigid surface and flexible fabric surface are interconnected by
a plurality of flexible links to define a container with side walls
to receive a flowable and settable wall forming material. The wall
form assembly offers the advantages of being significantly lighter,
less labour intensive and less expensive than existing formworks.
The wall form assembly permits efficient waterproofing and
insulation of the constructed wall.
Inventors: |
Fearn, Richard N.; (British
Columbia, CA) ; Bentz, Herbert Walter; (British
Columbia, CA) |
Correspondence
Address: |
KOLISCH HARTWELL, P.C.
520 S.W. YAMHILL STREET
SUITE 200
PORTLAND
OR
97204
US
|
Family ID: |
22791291 |
Appl. No.: |
10/312645 |
Filed: |
March 5, 2003 |
PCT Filed: |
June 21, 2001 |
PCT NO: |
PCT/CA01/00904 |
Current U.S.
Class: |
249/18 ;
52/309.12; 52/742.14 |
Current CPC
Class: |
E04B 2/8658 20130101;
E04B 2/8664 20130101 |
Class at
Publication: |
249/18 ;
52/309.12; 52/742.14 |
International
Class: |
E04G 011/00; E02D
027/00; E04G 021/00; E04G 023/00; E04B 001/00; E04C 001/00 |
Claims
We claim;
1. A wall form assembly comprising: a substantially rigid surface
to maintain the form assembly in a pre-determined orientation; at
least one flexible, fabric surface spaced from the rigid surface to
define a container with side walls; and a plurality of flexible
links extending between the side walls of the container to position
the at least one flexible, fabric surface with respect to the rigid
surface.
2. A wall form assembly as claimed in claim 1 in which the at least
one flexible, fabric surface is a woven material and each of the
flexible links comprises a tie extending from the material.
3. A wall form assembly as claimed in claim 2 in which each tie
comprises a loop of material.
4. A wall form assembly as claimed in claim 2 in which each tie
comprises a drop stitch of the warp or weft of the woven
material.
5. A wall form assembly as claimed in claim 3 in which each loop is
anchored to the substantially rigid surface.
6. A wall form assembly as claimed in claim 5 in which each loop is
anchored to the substantially rigid surface by a hook member
mounted to said surface.
7. A wall form assembly as claimed in claim 5 in which each loop is
anchored to the substantially rigid surface by gluing to said
surface.
8. A wall form assembly as claimed in claim 1 in which the
substantially rigid surface is formed from panels of plywood.
9. A,wall form assembly as claimed in claim 1 in which the
substantially rigid surface is formed from panels of rigid
insulation material.
10. A wall form assembly as claimed in claim 9 in which the rigid
insulation material is extruded polystyrene (XPS).
11. A wall form assembly as claimed in claim 9 in which the rigid
insulation material is expanded polystyrene (EPS).
12. A wall form assembly as claimed in claim 1 in which the at
least one flexible, fabric surface is formed from a plurality of
fabric sheets with each sheet being joined to an adjacent sheet by
a fastener.
13. A wall form assembly as claimed in claim 12 in which the
fastener comprises a zipper.
14. A wall form assembly as claimed in claim 1 in which the at
least one flexible, fabric surface is impermeable to water.
15. A wall form assembly as claimed in claim 14 in which the
flexible, fabric surface is rendered impermeable to water by a
waterproof coating.
16. A wall form assembly as claimed in claim 15 including a water
drainage layer adjacent the waterproof coating.
17. A wall form assembly as claimed in claim 1 in which the
plurality of flexible links extend between the side walls of the
container in a regular pattern on about 3 inch centers.
18. A wall form assembly as claimed in claim 1 in which the
substantially rigid surface defines one side wall of the container
and a single flexible fabric surface defines the other side wall of
the container.
19. A wall form assembly as claimed in claim 1 in which an outer
substantially rigid surface defines one side wall of the container,
an intermediate rigid surface defines a middle layer, and an outer
flexible fabric surface defines the other side wall of the
container.
20. A wall form assembly as claimed in claim 19 in which the
intermediate rigid surface is a rigid insulation panel.
21. A wall form assembly as claimed in claim 19 in which the
flexible links extend between the outer substantially rigid surface
and the outer flexible fabric surface through openings formed in
the intermediate rigid surface.
22. A wall form assembly as claimed in claim 1 in which a first
outer flexible fabric surface defines one side wall of the
container, an intermediate rigid surface defines a middle layer and
a second outer flexible fabric surface defines the other side wall
of the container.
23. A wall form assembly as claimed in claim 22 in which the
intermediate rigid surface is a rigid insulation panel.
24. A wall form assembly as claimed in claim 22 in which the
flexible links extend between the first and second outer flexible
fabric surfaces through openings formed in the intermediate rigid
surface.
25. A wall form assembly as claimed in claim 23 in which the
intermediate rigid surface is spaced substantially equidistantly
from the first and second outer flexible fabric surfaces.
26. A wall form assembly as claimed in claim 23 in which the
intermediate rigid surface is positioned to contact one of the
first and second outer flexible fabric surfaces.
27. A wall form assembly as claimed in claim 1 including a corner
tensioning member installable at changes in direction of the wall
form assembly.
28. A wall form assembly as claimed in claim 27 in which the corner
tensioning member comprises a mounting bracket positionable against
the rigid surface between the side walls of the container adjacent
a corner region, the mounting bracket including a protruding flange
that extends into the corner region for attachment to the flexible
fabric surface to support and maintain tension of the fabric
surface through the change in direction in the wall form
assembly.
29. A wall form assembly as claimed in claim 28 in which protruding
flange is formed with a plurality of openings therethrough.
30. A wall form assembly comprising: a substantially rigid surface
to maintain the form assembly in a pre-determined orientation; at
least one flexible, fabric surface spaced from the rigid surface to
define a cavity therebetween; and a plurality of flexible links
extending between the flexible, fabric surface and the
substantially rigid surface to position the fabric surface with
respect to the rigid surface.
31. A method for constructing a wall comprising the steps of:
connecting together a substantially rigid surface and at least one
spaced flexible, fabric surface by a plurality of flexible links to
define a container with side walls, the rigid surface acting to
maintain the flexible, fabric surface in a desired configuration;
and supplying a flowable and settable wall material to
substantially fill the container to form a wall when the wall
material has set.
32. The method of claim 31 in which the substantially rigid surface
is positioned to define one side wall of the container and a single
flexible fabric surface is positioned to define the other side wall
of the container.
33. The method of claim 31 in which an outer substantially rigid
surface is positioned to define one side wall of the container, an
intermediate rigid surface is positioned to define a middle layer,
and an outer flexible fabric surface is positioned to define the
other side wall of the container.
34. The method of claim 33 in which the intermediate rigid surface
is a rigid insulation panel.
35. The method of claim 33 in which the flexible links extend
between the outer substantially rigid surface and the outer
flexible fabric surface through openings formed in the intermediate
rigid surface.
36. The method of claim 31 in which a first outer flexible fabric
surface is positioned to define one side wall of the container, an
intermediate rigid surface is positioned to define a middle layer
and a second outer flexible fabric surface is positioned to define
the other side wall of the container.
37. The method of claim 36 in which the intermediate rigid surface
is a rigid insulation panel.
38. The method of claim 36 in which the flexible links extend
between the first and second outer flexible fabric surfaces through
openings formed in the intermediate rigid surface.
39. The method of claim 31 including the additional step of
installing a corner tensioning member at changes in direction of
the wall form assembly.
40. The method of claim 39 in which the corner tensioning member is
a mounting bracket positionable against the rigid surface between
the side walls of the container adjacent a corner region, the
mounting bracket including a protruding flange that extends into
the corner region for attachment to the flexible fabric surface to
support and maintain tension of the fabric surface through the
change in direction in the wall form assembly.
41. A wall form assembly comprising: a structural surface to
maintain the form assembly in a pre-determined orientation; at
least one flexible membrane interconnected with the structural
surface by a plurality of flexible links to position the at least
one flexible membrane with respect to the structural surface to
define a space therebetween to receive a flowable and settable
material.
42. A wall form assembly as claimed in claim 41 in which the
structural surface is a rigid surface.
43. A wall form assembly as claimed in claim 42 in which the rigid
surface is formed from panels of rigid insulation.
44. A wall form assembly as claimed in claim 41 in which the at
least one flexible membrane is a flexible material able to resist
tensile forces.
45. A wall form assembly as claimed in claim 41 in which the at
least one flexible membrane is a woven fabric material and each of
the flexible links comprises a tie woven into the material.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to the field of forms
constructed to be filled with concrete or other flowable and
settable materials, and more particularly to a pre-fabricated
concrete wall forming system that includes at least one wall formed
of fabric.
BACKGROUND OF THE INVENTION
[0002] Wall forms have been in existence since Roman times. While
significant changes in materials have occurred over the years, the
basic principle remains the same: create a cavity using spaced,
rigid flat surfaces into which a flowable and settable building
material is deposited and remove the surfaces after the material
has set to leave the wall in place. in early times, the rigid
surfaces were made from hand cut lumber. In more modern times,
steel, plywood or even rigid plastic are used. Bracing to hold the
forms together were made of rope or wood in the past. Now they are
made from steel or plastic rods.
[0003] Current methods for forming walls of concrete involve
setting up a pair of spaced, rigid flat surfaces, generally formed
from plywood, in an upstanding configuration. Fluent concrete
material is then poured into the gap to create an upstanding wall
when the concrete seats. Generally, such walls are formed atop an
existing footing.
[0004] Existing wall forming methods suffer from several
drawbacks:
[0005] 1. The use of removable rigid surfaces requires their
installation at the location of the proposed foundation wall. Once
the concrete is set in place, the bracing members must be removed
(or broken) to enable the rigid surfaces to be stripped from the
formed wall and taken to the next jobsite. This requires additional
labour. In addition, there can be damage to the rigid surfaces both
from the acidity of the concrete as well as mishandling during
shipment, installation and stripping.
[0006] 2. Most foundation walls are required by code to provide a
certain level of insulation. With the use of rigid removable wall
forms, the insulation (normally a rigid insulation) must be
installed after the formwork has been removed.
[0007] 3. The outside surface of most concrete foundation walls are
required by code to he damp proofed to prevent moisture from
surrounding soils from penetrating the concrete. Using existing
wall forming techniques, this must be done after the rigid surfaces
has been stripped from the concrete. This adds additional expense
and labour to the process of creating a foundation wall.
[0008] To overcome the problems with removable rigid form
assemblies, alternative techniques and equipment have been
developed. For example, U.S. Pat. No. 4,154,061 to Umemoto
discloses a fabric form for concrete formed from reinforced fabric
sheets. The resulting fabric forms are suitable for low footings,
but the forms are insufficiently rigid to permit formation of
rigid, vertically upstanding foundation walls. Concrete when
constrained in vertical fabric forms tends to flow under gravity to
cause outward bulging of the fabric walls with an vertically
extending S curve such that the fabric form fails to maintain the
desired straight vertical wall shape.
[0009] Co-inventor, Richard N. Fearn, of the present invention is
the owner of U.S. Pat. Nos. 5,224,321 and 5,794,393, the
disclosures of which are incorporated herein by reference. These
patents disclose the notion of using fabric to create concrete
forms using an external framework or an internal bracing system to
reduce bulging of the fabric side walls. Patent Co-operation Treaty
International application No PCT/CA98/00619 owned by inventor Fearn
discloses a fabric form system designed for the efficient and
inexpensive production of footings using an external support
structure for the fabric.
SUMMARY OF THE INVENTION
[0010] In view of the above discussion, there is a need for a
fabric form system to create walls, particularly foundation walls,
formed from concrete. To address this need, the inventors have
developed an system that relies on a rigid form surface in
combination with a flexible, fabric surface. The rigid surface and
the flexible fabric surfaces are interconnected by an array of
links that serve to prevent bulging of the fabric surface when
fluent concrete material is introduced between the rigid surface
and the fabric surface. The rigid surface acts to maintain the form
assembly in the desired generally vertical orientation.
[0011] Accordingly, the present invention provides a wall form
assembly comprising:
[0012] a substantially rigid surface to maintain the form assembly
in a pre-determined orientation;
[0013] at least one flexible, fabric surface spaced from the rigid
surface to define a container with side walls; and plurality of
flexible links extending between the side walls of the container to
position the at least one flexible, fabric surface with respect to
the rigid surface.
[0014] In a further aspect, the present invention provides a method
for constructing a wall comprising the steps of:
[0015] connecting together a substantially rigid surface and at
least one spaced flexible, fabric surface by a plurality of
flexible links to define a container with side walls, the rigid
surface acting to maintain the flexible, fabric surface in a
desired configuration; and
[0016] supplying a flowable and settable wall material to
substantially fill the container to form a wall when the wall
material has set.
[0017] In a still further aspect the present invention provides a
wall form assembly comprising:
[0018] a structural surface to maintain the form assembly in a
pre-determined orientation;
[0019] at least one flexible membrane interconnected with the
structural surface by a plurality of flexible links to position the
at least one flexible membrane with respect to the structural
surface to define a space therebetween to receive a flowable and
settable material.
[0020] The wall form assembly and method of the present invention
offer the advantage of significant weight reduction by replacing a
rigid surface with a fabric surface. In some cases the rigid
surface is a light weight insulation panel which offers additional
weight savings. The result is a wall form assembly that is easier
to ship, carry and install. There is less labour involved as in
most embodiments, the rigid and fabric surfaces are left in place
on the formed wall so that stripping is not required. In addition,
the rigid surface is preferably a rigid insulation panel and the.
fabric surface is preferably treated to be water impermeable so
subsequent insulation and water proofing of the formed wall are
unnecessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Aspects of the present invention are illustrated, merely by
way of example, in the accompanying drawings in which:
[0022] FIG. 1 is a perspective view of a prior art wall form system
using steel supports, plywood and steel ties;
[0023] FIG. 2 is a section view through a completed foundation wall
and the wall form assembly according to an embodiment of the
present invention, and is as seen on line 2-2 of FIG. 2a;
[0024] FIG. 2a is a fragmentary side elevation view of a portion of
the completed foundation wall formed using the wall form assembly
of the present invention;
[0025] FIG. 3 is a detail view of the flexible fabric layer of
woven material according to a preferred embodiment showing links
extending from the woven material;
[0026] FIG. 4 is a detail view of an embodiment of the present
invention that uses a rigid insulation panel as the rigid
surface;
[0027] FIG. 5 is a detail view showing a preferred manner in which
the links are received in cavities in the rigid insulation
panel;
[0028] FIG. 6 is a detail view similar to FIG. 5 showing the links
glued in place within the cavities;
[0029] FIG. 7 is a detail view of an alternative embodiment in
which the links extending from the flexible fabric surface are
mounted to the rigid surface by hooks;
[0030] FIG. 8 is a detail view of a further embodiment formed from
an outer flexible, fabric layer, a intermediate rigid insulation
layer and an outer rigid layer with links extending between the
outer layers through the intermediate layer;
[0031] FIG. 9 is a detail view of a still further embodiment formed
from a pair of outer flexible fabric layers sandwiching a rigid
intermediate layer spaced equidistantly from the fabric layers;
[0032] FIG. 9a is a detail view of an alternative embodiment
similar to that of FIG. 9 except that the rigid intermediate layer
is adjacent one of the fabric layers;
[0033] FIG. 10 is a detail view showing a preferred corner bracing
arrangement; and
[0034] FIG. 11 is a detail view of a clip used with the wall form
assembly of the present invention to hold reinforcing bar.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Referring to FIG. 1, there is shown a conventional prior art
wall form structure 10 positioned atop an existing footing 12. The
wall form structure includes a series of plywood or steel panels 14
that are supported by an external framework 16 to define a pair of
spaced, rigid planar surfaces with a cavity 18 therebetween to
received fluent concrete. The spacing of the panels 14 is
maintained by rigid steel or plastic rods 20 that extend between
the panels. Once the concrete is set, external framework 16 and
panels 14 are removed in a process known as "stripping" to leave a
completed tree standing wall atop footing 12.
[0036] The wall form assembly of the present invention was
developed to minimize or avoid the requirement of stripping the
completed wall. FIGS. 2 and 2a. show an exemplary wall form
assembly 30 according to the present invention in cross-section and
elevation. The wall form assembly is created atop an existing
footing 12 that sits on site surface 15. The wall form assembly
preferably comprises a structural surface 32 to maintain the form
assembly in a pre-determined orientation and at least one flexible
membrane 34 interconnected with the structural surface 32 by a
plurality of flexible links 36. Links 36 act to position flexible
membrane 34 with respect to the structural surface 32 to define a
space 38 therebetween to receive a flowable and settable material
such as concrete 40.
[0037] Preferably, structural surface 32 comprises a substantially
rigid surface such as series of joined panels of plywood that are
braced using conventional upper and lower supports 42 and 43,
respectively, to maintain the structural surface in an upright,
generally vertical orientation. It will be readily apparent to a
person skilled in the art that alternative bracing arrangements for
supporting structural surface 32 are possible.
[0038] Structural surface 32 must be sufficiently rigid and of
appropriate strength to support the pressure of the concrete while
setting and the tensile loads generated by links 36 as flexible
membrane 34 acts to confine the concrete at the opposite side of
the form assembly from structural surface 32. To this end,
structural or rigid surface 32 can be formed from panels of plywood
as previously mentioned. Alternatively, surface 32 can be formed
from panels of rigid insulation material. This technique has the
advantage that walls are pre-formed with insulation and a separate
application of insulation of wall formation is unnecessary. By way
of example, the rigid insulation material can be conventional
extruded polystyrene (XPS) or expanded polystyrene (EPS)
panels.
[0039] Flexible membrane 34 is selected to be of sufficient
strength to resist the pressure of the fluent concrete without
tearing. Preferably, flexible membrane 34 comprises a woven fabric
surface. An example of an appropriate woven material is
manufactured by Fabrene, Inc under the name FABRENE. Another
example is a woven polypropylene geotextile fabric material as
manufactured and distributed by AMOCO Corporation of Mich., U.S.
However, any non-woven flexible material member such as polymer
sheeting can be substituted for the woven fabric material.
[0040] Flexible membrane 34 can be semi-rigid. For example,
flexible membrane 34 can be formed from wire mesh with a covering
membrane. Alternatively, flexible membrane 34 can be a plastic
sheet. It is sufficient that flexible membrane 34 be a relatively
light weight material that is capable of withstanding the tensile
forces generated by the flowable concrete.
[0041] As best shown in FIG. 2a, flexible membrane 34 is preferably
supplied in the form of discrete sheets in which each sheet is
joined to an adjacent sheet by a fastener. In FIG. 2a, the sheets
are formed from woven fabric material that are joined by zippers
45. Alternative fasteners include but are not limited to hook and
loop fasteners, double sided tape and staples applied into a board
overlapping the edges of the sheets. The fasteners used will tend
to depend upon the material of flexible membrane 34.
[0042] Structural surface 32 and flexible membrane 34 are
preferably supplied in sheets or panels of uniform dimensions to
allow form walls of a desired length to be assembled. For example,
panels dimensioned to be 4 feet wide by 8 feet high provide
components parts that are conveniently handled for efficient
assembly. Rigid structural surfaces 32 can be joined together in a
standard manner such as nailing, gluing or interlocking of tongue
and groove connectors 98 formed in the side edges (see FIG.
10).
[0043] Referring to FIG. 2, it is necessary to brace flexible
membrane 34 to minimize bulging of the membrane and ensure sealing
of the upper and lower edges. Preferably, this is achieved by
constructing a framework adjacent the flexible membrane comprising
a lower kicker 37 and an upper whaler 39 to which the flexible
membrane is stapled at 47. A series of spaced vertical braces 41
extend between the kicker and whaler. Preferably, the kicker,
whaler and braces are formed from 2.times.4 lumber count to
size.
[0044] Flexible membrane 34 is preferably impermeable to water to
provide waterproofing for the finished wall. In the event that
flexible membrane 34 is a woven fabric surface a waterproof coating
48 can be applied to prevent water access. In addition, a water
drainage layer 49 is provided adjacent the waterproof coating to
move water away from the constructed wall.
[0045] As best shown in FIG. 2, flexible membrane 34 and rigid
structural surface 32 define a container with side walls to confine
concrete in a flowable state. Membrane 34 and rigid surface 32 are
joined together by a plurality of flexible links 36 extending
between the side walls of the container that serve to position the
flexible membrane with respect to the anchored rigid structural
surface. To spread the tensile forces generated by the flowable
concrete as evenly as possible it is preferably that flexible links
36 extend between the side walls of the container in a regular
pattern on about 3 inch centers (see FIG. 2a). The length of the
links will vary depending on the thickness of the concrete wall
being poured. For example, flexible lines 36 that are 8 inches long
are used form a wall that is of average thickness.
[0046] Flexible links 36 must be securely anchored to the surfaces
between which the links extend. In the case of a flexible membrane
34 formed from a woven fabric material, it is preferable that each
link 36 comprises a tie 48 woven or sewn into the material. As best
shown in FIG. 3, which is a detail view of a woven fabric surface
50, each tie 48 comprises a drop stitch defining a loop of material
extending from the warp or weft of surface 50. At the opposite end
of each tie 48 from woven fabric surface 50, the tie is preferably
anchored to structural surface 32. By way of example, FIGS. 4 to 6,
show various techniques by which ties 48 are connected to a rigid
insulation panel 54. In FIG. 4, holes 56 are formed through the
insulation panel aligned with ties 48. The ties are inserted
through holes 56 such that their distal ends 58 protrude from the
opposite side of the insulation panel. The ties are glued in place
using an appropriate polymer glue. In FIGS. 5 and 6, cavities 60
are formed in the rigid insulation to receive the distal ends of
the ties. Cavities 60 are filled with polymer glue 62 to anchor the
tie ends to the rigid insulation.
[0047] FIG. 7 illustrates a still further anchoring technique for
connecting ties 48 to the structural surface 32. In this case,
structural surface 32 can be a plywood panel or a rigid insulation
panel. Hook members 64 are mounted to the structural surface 32 by
gluing, nailing, stapling or the like. Hook members 64 are
preferably injection molded plastic pieces. Each hook members 64 is
inserted through the loop of a tie 48 to interconnect flexible
woven surface 5O with rigid structural surface 32. It will be
appreciated by a person skilled in the art that alternative
techniques are possible for anchoring flexible links 36 to flexible
membrane 34 and rigid structural surface 32. It is sufficient that
flexible links 36 be securely anchored at each surface in order to
be able to resist tensile force resulting from introduction of the
flowable concrete between the surfaces.
[0048] Ties used with a woven fabric flexible surface will
preferably be formed from the same fabric material as the woven
surface. It is also possible to make the ties from flexible plastic
that is bonded at each end to one of structural surface 32 and
flexible membrane 34.
[0049] If the rigid structural surface 32 is formed from plywood,
the wall form system illustrated in FIG. 7 is similar to a
conventional form as illustrated in FIG. 1 except for the
significant modification that one rigid surface is replaced with a
flexible membrane joined to the remaining rigid surface by an array
of flexible links. One advantage of such an arrangement is that the
wall form of the present invention is significantly lighter in
weight and is therefore easier to manipulate and install. Material
costs are also reduced. There is less labour involved as only the
plywood surface needs to be stripped once the concrete is set. The
flexible membrane remains in place against one side of the finished
wall to act as a damp proofing barrier.
[0050] If the rigid structural surface 32 is formed from a rigid
insulation panel, the wall form system illustrated in FIG. 7 offers
the additional advantage that the rigid insulation panel performs a
dual function as a side wall co-operating with the flexible
membrane to contain the flowable and an insulating member. Once the
concrete is set, no stripping is required as the rigid insulation
panel on one side and the flexible member on the opposite side of
the wall remain in place. The rigid insulation panel and flexible
membrane combination provide a light weight modular wall form
assembly that enjoys reduced shipping, installation and handling
costs.
[0051] The wall form assembly of the present invention can be set
up in alternative arrangements from that illustrated in FIG. 7
[0052] For example, FIG. 8 shows an arrangement in which a rigid
structural surface 32 (a plywood panel or a rigid insulation panel)
defines one side wall of the form. An intermediate rigid surface 70
preferably formed from a rigid insulation panel defines a middle
layer, and an outer flexible membrane 34 ( a woven fabric surface)
defines the other side wall of the form. In the wall form assembly
of FIG. 8, flexible links 36 extend between the outer rigid
structural surface 32 and the outer flexible membrane 34 through
openings 72 formed in the intermediate rigid surface 70.
[0053] FIG. 9 illustrates a further embodiment of the wall form
assembly of the present invention in which a first outer flexible
membrane 75 (a woven fabric surface) defines one side wall of the
form. There is an intermediate rigid surface 78 comprising a rigid
insulation panel that defines a middle layer and a second outer
flexible membrane 80 that defines the other side wall of the
container. Flexible links in the form of loop ties 82 extend
between the first and second outer flexible membranes through
openings formed in the intermediate insulation panel. This wall
form assembly provides a light weight structure in which the middle
insulation layer is braced to support the entire form. Once the
concrete sets, the internal middle insulation layer is protected
from the environment by a layer of concrete and the outermost
flexible membranes which remain in place.
[0054] As illustrated in FIG. 9, the middle insulation panel 78 can
be positioned essentially equidistantly from the first and second
outer flexible membranes 75 and 80. In this configuration, when
concrete is poured, the insulation is sandwiched between two
thicknesses of concrete.
[0055] Alternatively, as illustrated in FIG. 9a, the intermediate
insulation panel 78 can be positioned to contact one of the first
and second outer flexible fabric surfaces to create a single
internal concrete layer sandwiched between a woven fabric layer 75
on one side and an insulation panel 78 and a woven fabric layer 80
on the opposite side. This arrangement is preferred as it provides
a single concrete wall that is protected from the environment. The
use of two outer flexible membranes provides the best possible
anchoring for the ends of links 82.
[0056] FIG. 10 shows a preferred tensioning arrangement installable
at changes in direction of the wall form assembly to ensure that
corners are properly shaped. FIG. 10 is a perspective view of a
corner in a wall form 30 constructed according to the present
invention with a rigid structural surface 32 and a flexible
membrane 34 defining the outer form walls joined by a plurality of
flexible links 36. Within the interior 38 of the form between the
outer form walls, a corner tensioning member 85 is provided.
Tensioning member 85 is positionable adjacent a corner region 89
and is mounted to rigid structural surface 32 via a mounting
bracket in the form of angle bracket 88. The angular separation of
the surfaces of angle bracket 88 is selected to corresponding to
the angle of the corner region. Tensioning member 85 includes a
protruding angled flange 90 that extends across interior 38 from
rigid structural surface 32 for attachment to flexible membrane 34
to support and tension the membrane through the change in
direction. The flexible membrane is stapled or glued along edge 92
of flange 90 which defines the corner edge of the form assembly.
Protruding flange 90 is formed with a plurality of openings 95
therethrough to allow for the free passage of flowable concrete
around the corner.
[0057] FIG. 11 is a top plan view illustrating a clip 100 mountable
between panels of rigid insulation 32 to hold vertically aligned
reinforcing bar 102 in place within interior 38 of the wall form.
Clip 100 is preferably formed from molded plastic.
[0058] Although the present invention has been described in some
detail by way of example for purposes of clarity and understanding,
it will be apparent that certain changes and modifications may be
practiced within the scope of the appended claims.
* * * * *