U.S. patent application number 10/016456 was filed with the patent office on 2003-05-01 for precast modular building panel and vertically oriented method of manufacturing same.
This patent application is currently assigned to Housing Technology, Inc.. Invention is credited to Stephens, Rodney O., Stocking, Harrel Dale JR..
Application Number | 20030079438 10/016456 |
Document ID | / |
Family ID | 21777215 |
Filed Date | 2003-05-01 |
United States Patent
Application |
20030079438 |
Kind Code |
A1 |
Stephens, Rodney O. ; et
al. |
May 1, 2003 |
Precast modular building panel and vertically oriented method of
manufacturing same
Abstract
A molded composite construction panel formed in a vertically
oriented continuous molding procedure included a lightweight
cellular core of rigid foam material and a relatively thin skin of
fiber reinforced concrete encasing the core. The panel further
including at least one integrally formed multi-faceted channel
being substantially coextensive with at least one edge of the
panel. A method of forming a building panel is also disclosed
comprising the steps of providing a mold having a mold cavity,
disposed vertically, that defines the mold surface for forming the
exposed finish surfaces of a molded wall panel, where the mold
cavity bottom and side edge walls define the edge walls of the
molded wall panel. A foam insert is positioned and secured in the
mold cavity. A slurry of concrete, sand, and fiber strands is
formed to produce a homogeneous panel mixture. The mold cavity is
filled with the panel mixture. Once cured, the integral assembly of
cured panel mixture and foam insert is removed from the mold
cavity.
Inventors: |
Stephens, Rodney O.;
(Scottsdale, AZ) ; Stocking, Harrel Dale JR.;
(Scottsdale, AZ) |
Correspondence
Address: |
Matthew F. Jodziewicz, Esq.
Suite 836
3660 Wilshire Boulevard
Los Angeles
CA
90010
US
|
Assignee: |
Housing Technology, Inc.
|
Family ID: |
21777215 |
Appl. No.: |
10/016456 |
Filed: |
November 1, 2001 |
Current U.S.
Class: |
52/782.1 ;
52/309.1; 52/309.12; 52/309.17; 52/309.4; 52/784.15 |
Current CPC
Class: |
E04C 2/2885 20130101;
B28B 23/0068 20130101; B28B 23/0056 20130101; C04B 14/06
20130101 |
Class at
Publication: |
52/782.1 ;
52/784.15; 52/309.1; 52/309.4; 52/309.12; 52/309.17 |
International
Class: |
E04C 002/00 |
Claims
What is claimed is:
1. A molded composite construction panel formed in a vertically
oriented continuous molding procedure comprising: A lightweight
cellular core of rigid foam material; A relatively thin skin of
glass fiber reinforced concrete encasing said core, Said panel
further including at least one integrally formed channel being
substantially coextensive with at least one edge of said panel.
2. A panel as in claim 1 wherein said channel is at least partially
arcuate in cross-section.
3. A panel as in claim 1 wherein said channel is multi-faceted in
cross-section.
4. A panel as in claim 3 wherein said multi-faceted channel is
semi-hexagonal in cross-section.
5. A panel as in claim 1 wherein said relatively thin skin of glass
fiber reinforced concrete has about {fraction (1/16)} to 1/2 inch
thickness.
6. A panel as in claim 1 further comprising: Electrical raceway
means embedded within said panel during the molding procedure with
respective raceways being adapted for interconnection upon
securement of said panel to form an internal electrical raceway
network.
7. A panel as in claim 6 wherein said panel is further provided
with recess means in communication with said raceway, said recess
means being adapted for receiving an electrical junction box.
8. A panel as in claim 1 further comprising raceway means embedded
within said panel during the molding procedure with the respective
raceways being adapted for interconnection upon securement of said
panel to form an internal raceway network.
9. A panel as in claim 1 further comprising: a channel, integrally
formed in the side of said panel, being adapted for receiving
raceway means therein.
10. A molded composite construction panel formed in a vertically
oriented, continuous molding procedure, comprising: a light-weight
cellular core of rigid foam material with chamfered corners; a
relatively thin skin of fiber reinforced concrete encasing said
core, said panel further including connection means for securing
adjacently placed panels.
11. A panel as in claim 10 wherein said connection means comprises:
At least one multi-faceted channel integrally formed in and
substantially coextensive with at least one edge of said panel.
12. A panel as in claim 10 wherein said connection means comprises:
A multi-faceted channel integrally formed in and substantially
coextensive with each side edge of said panel.
13. A panel as in claim 10 wherein said multi-faceted channel is
semi-polygonal in cross-section.
14. A panel as in claim 13 wherein said at least one integrally
formed multi-faceted channel is semi-hexagonal in
cross-section.
15. A panel as in claim 10 wherein said relatively thin skin of
fiber reinforced concrete has about {fraction (1/16)} to 1/2 inch
thickness.
16. A panel as in claim 10 further comprising: Electrical raceway
means embedded within said panel during the molding procedure with
respective raceways being adapted for interconnection upon
securement of said panel to form an internal electrical raceway
network.
17. A panel as in claim 16 wherein said panel is further provided
with recess means in communication with said raceway, said recess
means being adapted for receiving an electrical junction box.
18. A panel as in claim 10 further comprising water conduit means
embedded within said panel during the molding procedure with the
respective conduits being adapted for interconnection upon
securement of said panel to form an internal water conduit
network.
19. A panel as in claim 10 further comprising: a channel,
integrally formed in the side of said panel, being adapted for
receiving conduit means therein.
20. A molded composite construction panel formed in a vertically
oriented, continuous molding procedure, comprising: a light-weight
cellular core of rigid foam material; a skin of fiber reinforced
concrete encasing said core and having a thickness of about
{fraction (1/16)} to about 1/2 of an inch, said panel further
including at least one semi-hexagonal channel integrally formed in,
and substantially coextensive with, at least one side of said
panel.
21. A method of forming a building panel, comprising the steps of:
providing a mold having a mold cavity, disposed vertically, that
defines the mold surface for forming the exposed finish surface of
a molded wall panel, where the mold cavity bottom and side edge
walls define the edge walls of the molded wall panel; positioning
and securing a foam insert in said mold cavity; forming a slurry of
concrete, sand, and reinforcing fiber strands to produce a
homogeneous panel mixture; filling said mold cavity with said panel
mixture and leveling said panel mixture with the mold side edge
walls; effecting the cure of said panel mixture in said mold and
the bonding of said mixture to said foam insert; and, removing the
integral assembly of cured panel mixture and foam insert from said
mold cavity.
22. A method of forming a building panel, as in claim 21, further
comprising the step of: placing a selected detail form contiguous
to the surface of said panel mixture exposed at the top of said
mold, while said panel mixture remains in said mold cavity, in a
position to shape said panel mixture at said exposed top edge so
that all four edges of the molded panel are formed into the desired
shapes.
23. A method of forming a building panel, as in claim 21, further
comprising the step of: inserting bottom and side details in said
mold cavity prior to filling said mold cavity with said panel
mixture to shape said panel mixture at said bottom and side
edges.
24. A method of forming a building panel, as in claim 21, further
comprising the step of: spraying said mold cavity with a mold
release to facilitate the removal of the integral assembly of cured
panel mixture and foam insert from said mold cavity.
25. A method of forming a building panel, as in claim 21, wherein
the step of positioning and securing a foam insert in said mold
cavity further comprises the step of: inserting, on opposite sides
of said foam insert positioned in said mold cavity, spacing fingers
intermediate said foam insert and the mold cavity walls for keeping
said foam insert centered in said mold cavity and preventing said
foam insert from moving and warping as the mold cavity is filled
with panel mixture.
26. A method of forming a building panel, as in claim 25, further
comprises the step of: withdrawing said spacing fingers from said
mold cavity gradually as said panel mixture fills said mold cavity
and bonds with said foam insert, allowing the partially set-up
panel mixture to hold said foam insert in position.
27. A method of forming a building panel, as in claim 21, wherein
the step of positioning and securing a foam insert in said mold
cavity further comprises the step of: providing hold-down members,
mounted on an upper exposed edge of the foam insert, for holding
said foam insert in position and prevent it from moving position
while filling said mold cavity with panel mixture.
28. A method of forming a building panel, as in claim 27, further
comprises the steps of: removing said hold-down members from said
foam insert as said panel mixture fills said mold cavity, sets up
and bonds with said foam insert, allowing the panel mixture to hold
said foam insert in position; adding additional mixture to cover
said foam insert; and, inserting an edge detail at the top of the
mold to form a channel in the edge of said panel.
29. A method of forming a building panel, as in claim 21, further
comprises the step of: mounting a vibrator on said mold for helping
to spread uniformly said panel mixture in said mold cavity.
30. A method of forming a building panel, as in claim 21, further
comprises the step of: providing a vertical channel in said foam
insert to allow rapid and uniform filling of said mold cavity.
31. A method of forming a building panel, as in claim 30, further
comprises the step of: cutting at least one vertical channel on at
least one side of said foam insert to allow rapid and uniform
filling of said mold cavity.
32. A method of forming a building panel, as in claim 21, wherein
the step of providing a mold having a mold cavity, disposed
vertically, defining the mold surface for forming the exposed
finish surface of a molded wall panel, where the mold cavity bottom
and side edge walls define three of the edge walls of the molded
wall panel, further comprises the step of: providing a mold having
two separate, vertically disposed mold cavities having a shared
common mold cavity wall for simultaneously producing two molded
wall panels.
33. A method of forming a building panel, comprising the steps of:
providing a mold having a mold cavity, disposed vertically, that
defines the mold surface for forming the exposed finish surface of
a molded wall panel, where the mold cavity bottom and side edge
walls define three of the edge walls of the molded wall panel;
positioning and securing a foam insert in said mold cavity; mixing
a liquids component including water; mixing thoroughly about 14
percent by weight of said liquids component with about 86 percent
by weight solids component consisting of cement, sand and
strengthening fiber components to produce a homogeneous panel
mixture; filling said mold cavity with said panel mixture and
leveling said panel mixture with the mold side edge walls;
effecting the setup and initial cure of said panel mixture in said
mold and the bonding of said mixture to said foam insert; and,
removing the integral assembly of partially cured panel mixture and
foam insert from said mold cavity.
34. A method as in claim 33, wherein said sand component in said
solids component is selected from a group consisting of plaster
wash sand, dolomite, perlite, silica, ground quartz and slack.
35. A method as in claim 33, wherein said sand component in said
solids component is comprised of a mixture consisting of plaster
wash sand and silica.
36. A method as in claim 35 wherein said plaster wash sand
comprises about 10 to 50 percent of said sand component, and said
silica comprises about 90 to 50 percent of said sand component, the
percentages being expressed as weight percentages.
37. A method as in claim 35 wherein said plaster wash sand
comprises about 10 to 90 percent of said sand component, and said
silica comprises about 90 to 10 percent of said sand component, the
percentages being expressed as weight percentages.
38. A method as in claim 33, wherein said strengthening fiber
component in said solids component is selected from a group
consisting of strands of glass fiber, polyprophelene, nylon, and
carbon or graphite fiber.
39. A method as in claim 38 wherein said fiber strands are about
1/2 to 3/4 inch in size.
40. A method as in claim 33 wherein the step of mixing a liquids
component including water further comprises the step of: adding an
acrylic polymer to control the curing time of said panel
mixture.
41. A method as in claim 40 wherein said acrylic polymer is added
to the liquids component in an amount of about 5 to 10 percent by
weight of said liquid component.
42. A method as in claim 33 wherein the step of mixing a liquids
component including water further comprises the step of: adding a
super plasticizer to control the flowability of said panel
mixture.
43. A method as in claim 42 wherein said super plasticizer is added
to the liquids component in an amount of about 1/2 to 8 ounces per
94 pounds of cement in said solids component.
44. A method as in claim 33 wherein the step of mixing a liquids
component including water further comprises the step of: adding a
concrete extender to control the curing of the panel mixture due to
temperature.
45. A method as in claim 44 wherein said concrete extender is added
to the liquids component in an amount of about 1/2 to 2 ounces per
94 pounds of cement in said solids component.
46. A method as in claim 33 wherein the step of mixing a liquids
component including water further comprises the step of: adding an
anti-foaming agent for controlling the creation of voids in said
molded panel.
47. A method as in claim 46 wherein said anti-foaming agent is
added to the liquids component in an amount of about 1/4 to 3/4
ounces per 94 pounds of cement in said solids component.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates in general to the building
wall panel art, and more particularly pertains to the art of
manufacturing a molded modular building wall panel formed from a
fiber reinforced concrete and a method of vertically molding
same.
[0003] 2. Description of the Prior Art
[0004] A long felt need in the construction industry, and more
particularly in the building wall panel field, is to find a
durable, yet relatively inexpensive construction method and
material that would allow the construction of attractive and
durable homes in a quick and economic manner.
[0005] Although the thrust of this need has initially been to
provide housing for low-income families or for first time home
buyers, any such construction method and material could also be
easily adapted for more expensive homes and multi-family housing
units.
[0006] One such attempt to create such a relatively inexpensive
construction method and material has resulted in the use of precast
or molded glass fiber reinforced concrete (GFRC) building
panels.
[0007] The development of lightweight precast construction panels
has been gradual and not without many shortcomings. Initial
attempts to manufacture such panels have met with many problems,
for example, attempting to lower the weight of a concrete panel
while maintaining its load bearing strength, various reinforcing
designs and inserts have been tried, for example, insulating foam
blocks were inserted into the panel during the molding process to
be encased within the GFRC matrix. However, such foam inserts,
while lessening the weight of the panel, posed new challenges in
laminating or bonding the concrete to the foam insert and in
producing a consistent and useful building panel.
[0008] While such foam inserts provided a tremendous benefit in
lessening the weight of the panel and insulating the structure
against heat and cold, great difficulties arose during the molding
process in keeping the foam inserts from warping or shifting. Such
warping or shifting of the foam inserts results in panels having
side walls with irregular thickness, voids and reduced load bearing
strength.
[0009] Accordingly, much work has been done in the casting of such
panels, all of which includes using a horizontally disposed or
oriented mold, open on top, to limit and control any warping or
shifting of the foam inserts due to hydrostatic pressures that
develop during the molding process. In this horizontal molding
process one face of the panel is flat on one face of the mold. A
layer, typically 1/4 of an inch of Glass Fiber Reinforced Concrete
(GFRC) is first poured onto the bottom face of the mold, then a
foam insert, such as a panel of expanded polystyrene foam, is
placed on top of the GFRC layer and some weight, such as sand bags
are placed on the foam insert to hold it in place from hydrostatic
pressures that arise subsequently when more GFRC is then poured
into the mold around the sides and top of the foam insert.
[0010] In this horizontal molding method, the mold has no top face,
so after removing the sand bags and pouring the GFRC on top of the
foam insert, the exposed GFRC layer had to be manually smoothed, as
it would become one of the finished panel faces. Various steps in
this horizontal molding process are difficult and inefficient,
including the need to hold the foam insert in position, produce
GFRC panel walls of uniform thickness and sufficient smoothness. It
is also difficult, with such methods, to achieve good bonding or
lamination between the foam and the GFRC.
[0011] Another problem with current methods of construction using
molded building panels is the methods by which these panels are
interconnected in the construction process. Some known methods
require the insertion of reinforcing bars with extending ends,
which extending ends are then used as lashing points for holding
the panels in place. However, these construction methods also
require added cost, expertise in properly encasing such reinforcing
bars and a greater expertise in the construction team workers
installing the panels.
[0012] By way of example, the prior art of casting such GFRC
building panels are found in such representative references as U.S.
Pat. No. 3,885,008 to Martin; U.S. Pat. No. 3,965,635 to Renkert;
U.S. Pat. No. 4,185,437 to Robinson; U.S. Pat. No. 4,232,494 to
Bauch et al.; U.S. Pat. No. 4,453,359 to Robinson; U.S. Pat. No.
4,531,338 to Donatt; U.S. Pat. No. 4,542,613 to Leyte-Vidal; U.S.
Pat. No. 4,691,490 to Leaver; and U.S. Pat. No. 6,182,416 B1 to
Bracklin.
[0013] However, the known molding processes are time consuming,
labor intensive, and operationally expensive and produce building
panels that are not only expensive, but also hard to obtain leading
to long construction delays in building the structures themselves.
Likewise, current building panels require costly construction
methods for connecting the panels into the desired structure.
[0014] The present invention provides a solution to these and other
problems of the present art in molded building panels by providing
a building panel that is light-weight, easily and quickly cast with
a minimal amount of labor needed in its manufacture and that is
easily interconnected during the construction process to produce a
sturdy structure.
[0015] At least in these respects, the method of construction and
composition of the present invention substantially departs from the
conventional concepts and designs of the prior art, and in so doing
provides a building panel and method primarily developed for the
purpose of providing a light-weight molded building panel for use
in constructing durable and economical housing or other structures
in a time efficient manner.
[0016] In these regards, at least, the present invention
substantially fulfills these needs of the present art in molded
building panel construction and manufacture.
SUMMARY OF THE INVENTION
[0017] In view of the foregoing disadvantages inherent in the known
types of building panels and methods of molding such panels now
present in the art, the present invention provides an improved
molded composite construction panel that is formed in a vertically
oriented continuous molding procedure. The panel of the present
invention has, in general, a lightweight cellular core of rigid
foam material and a relatively thin skin of glass fiber reinforced
concrete encasing the foam core.
[0018] The panel further has at least one integrally formed
channel. The channel may be arcuate or multi-faceted in which case
it would preferably be a semi-hexagon in cross-section, that is
substantially coextensive with at least one side edge of the panel
for construction connection purposes as will be better described
below. However, the channel can be of any other cross-sectional
shape such as a semi-circle, star, or X shape, just to indicate
three acceptable shapes as examples, without limitation. In
general, a goal for the choice of channel cross-sectional shape is
that when adjacent panels are connected, the abutting channels meet
to form a passageway big enough to hold at least one piece of
reinforcing bar (rebar) while allowing concrete to be poured into
the passageway to form an integral structure for reinforcing the
connected panel construction in situ.
[0019] As such, the general purposes of the present invention,
which will be described subsequently in greater detail, are to
provide a new and improved molded building panel and method of
making such panel as well as a method of connecting such panels in
construction, which have all the advantages of the prior art and
none of the disadvantages.
[0020] To attain this, the present invention in an embodiment for a
method of forming a building panel, generally includes the steps
of:
[0021] providing a mold having a mold cavity that is disposed
vertically. (It should be noted for clarity, that although the mold
cavity is disposed vertically, the panel being molded need not also
be vertically oriented as to its final installation, i.e., the mold
cavity being disposed vertically does not imply that the panel is
actually molded in its normal vertical position with the top of the
final panel at the top of the mold.) The mold cavity defines the
mold surface for forming the exposed finish surface of a molded
wall panel, where the mold cavity bottom and side edge walls define
the various edge walls of the molded wall panel.
[0022] positioning and securing a foam insert in the mold cavity.
The foam insert is inserted inside the panel to provide strength
and rigidity to the finished panel while at the same time lessening
the weight of the panel over a solid concrete panel and improving
thermal insulation;
[0023] forming a slurry of concrete, sand, and glass fiber strands
to produce a homogeneous panel mixture commonly referred to as a
GFRC panel mixture;
[0024] positioning in the mold (optionally) one or more reinforcing
bars in such positions as to be embedded within the GFRC in the
final panel;
[0025] filling the mold cavity with the panel mixture and leveling
the panel mixture with the mold side edge walls to fill out the
form of the mold cavity;
[0026] effecting the cure of the panel mixture in the mold and the
bonding of the panel mixture to the foam insert; and,
[0027] removing the integral assembly of cured panel mixture and
foam insert from the mold cavity.
[0028] It should be noted that the strength and flexibility of the
panels embodying the present invention can be used throughout a
structure for both load supporting and non-load supporting walls,
floors, headers and even roofs.
[0029] There has thus been defined, rather broadly, the more
important features of the invention in order that the detailed
description thereof that follows may be better understood, and in
order that the present contribution to the art may be better
appreciated. There are, of course, additional features of the
invention that will be described hereinafter and which will form
the subject matter of the claims appended hereto.
[0030] In this respect, before explaining at least one embodiment
of the invention in detail, it is to be understood that the
invention is not limited in its application to the details of
construction and to the arrangements of the components set forth in
the following description or illustrated in the drawings. The
invention is capable of other embodiments and of being practiced
and carried out in various ways. Also, it is to be understood that
the phraseology and terminology employed herein are for the purpose
of description and should not be regarded as limiting.
[0031] As such, those skilled in the art will appreciate that the
conception, upon which this disclosure is based, may readily be
utilized as a basis for the designing of other structures, methods
and systems for carrying out the several purposes of the present
invention. It is important, therefore, that the claims be regarded
as including such equivalent constructions insofar as they do not
depart from the spirit and scope of the present invention.
[0032] It is therefore an object of the present invention to
provide a new and improved molded building panel, construction and
connection methods, which have all the advantages of the prior art
molded building panels and none of the disadvantages.
[0033] It is another object of the present invention to provide a
new and improved molded building panel, construction and connection
methods, which may be easily and efficiently manufactured and
assembled.
[0034] It is a further object of the present invention to provide a
new and improved molded building panel, construction and connection
methods, which produce a durable and reliable construction.
[0035] An even further object of the present invention is to
provide a new and improved molded building panel, construction and
connection methods, whose design, structure, and construction steps
are simplified, while permitting a mastery and optimal control of
the molding and interconnecting process for such precast building
panels.
[0036] Still yet another object of the present invention is to
provide a new and improved molded building panel, construction and
connection methods, whose use and steps facilitate the construction
process.
[0037] Lastly, it is an object of the present invention to provide
a new and improved molded building panel, construction and
connection methods, which are safe for home and commercial
construction use.
[0038] These together with other objects of the invention, along
with the various features of novelty that characterize the
invention, are pointed out with particularity in the claims annexed
to and forming a part of this disclosure. For a better
understanding of the invention, its operating advantages and the
specific objects attained by its uses, reference should be had to
the accompanying drawings and descriptive matter in which there is
an illustrated preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The invention will be better understood and objects other
than those set forth above will become apparent when consideration
is given to the following detailed description thereof. Such
description makes reference to the annexed drawings wherein:
[0040] FIG. 1 is a molded building panel that has been constructed
in accordance with the principles of the present invention.
[0041] FIG. 2 is a cross-sectional view taken along the line 2-2 in
the direction shown in FIG. 1;
[0042] FIG. 3 is a cross-sectional view taken along the line 3-3 in
the direction shown in FIG. 1;
[0043] FIGS. 4A, 4B and 4C are cross-sectional views of various
type of channels or details formed in the sides of a molded panel
embodying the present invention;
[0044] FIGS. 5A, 5B, 5C, 5D and 5E are cross-sectional views of
different panel joining constructions utilizing a molded panel
embodying the present invention;
[0045] FIG. 6 is a side plan view of a mold useful for molding
panels embodying the present invention;
[0046] FIG. 7 is a cross-sectional view taken along the line 7-7 in
the direction shown in FIG. 6;
[0047] FIG. 8 is a cross-sectional view of a curved panel mold
useful for molding panels embodying the present invention;
[0048] FIG. 9 is a side view of a mold useful for molding panels
embodying the present invention having spacers and dividers
inserted (shown in dotted outline) to form multiple smaller
cavities for molding multiple small panels at the same time;
[0049] FIG. 10 is a cross-sectional view of a mold useful for
molding panels embodying the present invention illustrating that
the outer faces of the mold can be placed in multiple slots to form
panels of multiple thicknesses;
[0050] FIG. 11 is a side view of a mold useful for molding panels
embodying the present invention illustrating in dotted outline the
use of spacing fingers to maintain the desired position of the foam
core during the pouring process; and, FIG. 12 is a cross-sectional
side view taken along line 11-11 of FIG. 11 in the direction shown,
illustrating a single mold cavity with a foam core in place and
spacing fingers on both sides of the foam core to maintain precise
separation between the foam core and the mold faces.
[0051] Similar reference characters refer to similar parts
throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0052] With reference now in the drawings, and in particular in
FIG. 1 thereof, a new and improved molded building panel and
connection methods for such a panel, which embody the principles
and concepts of the present invention and generally designated by
the reference numeral 10 will be described. The construction of
such a panel will be described afterwards below.
[0053] The new and improved molded building panel 10 embodying the
present invention is comprised of a plurality of components that
are integrated into a single unit. Such components in their
broadest context include an internal foam insert 12 encased in a
matrix 14 of preferably glass fiber reinforced concrete. Such
components are individually configured and correlated with respect
to each other so as to attain the desired construction or
structural objective for which the panel is being manufactured,
that is, the size and shape of the panel may be changed to suit the
desired structural demands of the particular job and location of
the specific panel.
[0054] More specifically, with reference being made to the Figures,
the present invention includes a molded composite construction
panel 10 that is formed in a vertically oriented continuous molding
procedure described below. Note that the mold need not be precisely
vertical, but may be tilted by some amount from the vertical. Panel
10 has a lightweight cellular core of rigid foam material 12 that
is encased in a relatively thin skin of glass fiber reinforced
concrete 14. Relatively thin skin of glass fiber reinforced
concrete means, generally, an encasing layer having about {fraction
(1/16)} to 1/2 inch thickness.
[0055] Rigid foam material 12 preferably has chamfered or beveled
edges 13a and may also include a textured surface or additional
chamfered channels 13b on its faces to aid in bonding the foam
material 12 to the glass fiber reinforced concrete 14 surrounding
the foam material 12.
[0056] Panel 10 preferably has integrally formed multi-faceted
channels 16 that are substantially coextensive with the side edges
of panel 10 as shown in FIGS. 1 to 3. Channels 16 are best shaped
to be semi-polygonal in cross-section, such as a semi-hexagon for
joining two panels during construction, but may be other specific
faceted shapes as well as shown in FIGS. 4A, 4B, and 4C. The
shallower channel formed by a cross-sectional shape 22 as in FIG.
4A is useful for the panel sides, while the cross-sectional shapes
24, 26, shown in FIGS. 4B and 4C, respectively, are useful for the
top and bottom sides of the panel respectively.
[0057] Testing has shown that while many cross-sectional shapes are
useful, the greater the number of facets and planar intersections
found in the cross-sectional aspect of the channels, the greater
the strength when panels are joined.
[0058] Generally, as shown in FIGS. 5A and 5B, channels 16 are
butted one to another. Steel reinforcing bars are placed in the
channels and a concrete fill 30 is poured in to fill the channels.
Once the concrete fill 30 is hardened, the joint forms a very
strong construction, capable of bearing tremendous loads.
[0059] Wall ends and the sides of door and window openings can be
made as shown in FIG. 5C where the otherwise open channel 16 has
reinforcing bars 28 placed in it and a concrete fill 30 is molded
to the desired open edge shape.
[0060] FIGS. 5D and 5E illustrate various cross-sections of panels
and preferred uses for each in construction. FIG. 5D shows a panel
50 that is useful as a window/door header. On such window/door
header type panels, note that the upper channel 52 at the top of
the panel is preferably configured for the connecting and
supporting beam material to be poured into. The foam insert 54 is
shown with chamfered corners 56, and the rectangular bottom part 58
of the panel is formed with thick GFRC which typically would
include one or more rebars 60 inside it to provide tensile
strength.
[0061] The panel 62 shown in FIG. 5E, which is useful for the short
wall section below a window, has no channel on its upper edge 64,
but may optionally have one or more bolts 66 inserted in the GFRC
68 for use in fastening the window frame.
[0062] Electrical raceways, illustrated at reference numeral 18 in
FIG. 1 may be embedded within panel 10 during the molding process
with respective raceways in adjacent panels being adapted for
interconnection upon securement of the panels to form an internal
electrical raceway network so that an electrician will not have to
mar or dig into a panel during installation of a structure's
electrical wiring system. In addition, the panel is further
preferably provided with recesses 20 that are in communication with
an end of raceway passageways 18. Recesses are intended to be
adapted for receiving an electrical junction box.
[0063] Likewise, water conduits can also be embedded within the
panels during the molding procedure with the respective conduits
being adapted for interconnection upon the joining of adjacent
panels to form an internal water conduit network similar to that
discussed above for electrical wiring.
[0064] Both the electrical and water conduits may be either
embedded in the panels or open channels may be molded into the
panels to receive the wiring or pipes which are then covered over
with sheeting. It is preferred in many constructions to have these
conduits molded into the panels to avoid having to run unsightly or
even out of code wiring or plumbing outside of the walls of the
completed buildings.
[0065] A method embodying the present invention that is useful for
forming a building panel as described above, would include the
following described steps.
[0066] Step 1: Providing first a mold 32 that has a mold cavity 34
that is disposed vertically. Such a vertically disposed mold 32 is
shown in FIGS. 6 and 7. This vertical orientation is a departure
from known prior art and is significant in allowing not only
stronger panels to be cast quickly, but in allowing the molding
process to be more efficient than horizontal molding techniques
currently in use. The walls 36 of the mold cavity 34 define the
mold surface for forming the exposed finish surface of the finished
molded wall panel. Specifically, the mold cavity bottom 38 and side
edge walls 40 define edge walls 44 of the molded wall panel 10.
Note that the top of the panel need not be at the top of the mold;
in general, the panel will be molded in whatever orientation is
most convenient. For example, typical tall panels may be molded
lying on their side, and window headers may be molded upside-down
because they usually have rebar in their bottom edge, and it is
easier to place the rebar at the top of the mold.
[0067] Another aspect of the present invention is that the molds
may be varied to create panels of various thickness and shape.
Specifically, the overall thickness of the panel is determined by
how far each outside mold wall is from the middle wall when the
mold cavities are placed side by side as described below. At the
bottom, as shown in FIG. 10 and explained in greater detail below,
the horizontal steel base piece into which the vertical sides are
held, has slots at various distances from the middle wall, and the
outer wall of the mold can be inserted into any of those slots,
allowing panels to be made in several discrete thicknesses using
the same molds. Of course, the edge details that form the shape of
the panel edges must be customized for each thickness, but those
are normally formed from sheet metal and are cheap to make and easy
both to store and insert. The molds themselves are much bigger,
heavier and more expensive, so it is a real benefit that one mold
can be used to make panels having walls of different thicknesses.
It should be noted that the slots for inserting the outer walls
appearing in the horizontal steel base piece that are of a lesser
thickness than the panel being molded, do not get filled with GFRC
during the molding process because the metal edge details cover
them during molding.
[0068] Step 2: Positioning and securing a foam insert 12 in mold
cavity 34. It is essential that foam insert 12 be held both
securely and accurately in mold cavity 34, especially during the
pouring process described below which causes a great deal of
hydrostatic pressure to develop in mold cavity 34. These pressures
tend to distort or warp foam insert 12 and to cause it to "float"
as the slurry described is poured in cavity 34. Warping and
shifting of foam insert 14 can cause thin spots in the GFRC shell
of the finished molded panel unless properly controlled during the
pouring process as better explained below.
[0069] Step 3: Forming a slurry of concrete, sand, and glass fiber
strands to produce a homogeneous panel mixture. The composition and
selection of materials to form this slurry is critical, especially
in light of the vertical orientation of the mold 32 which requires
different compositions than that used for horizontal moldings.
[0070] In one preferred embodiment, the sand component is comprised
of a mixture consisting of plaster wash sand and silica sand where
the plaster wash sand comprises about 10 to 50 percent, and the
silica portion comprises about 90 to 50 percent of the sand
component, where the percentages are being expressed as weight
percentages. These are rough guidelines and also includes where the
plaster wash sand comprises about 10 to 90 percent, and the silica
portion comprises about 90 to 10 percent of the sand component.
Once again the percentages are being expressed as weight
percentages.
[0071] The strengthening fiber component in the solids component is
preferably selected from a group consisting of strands of glass
fiber, polyprophelene, nylon, and carbon or graphite fiber. More
specifically, the fiber strands are preferably selected to be about
1/2 to 3/4 inch in size. As is generally known in the art, the
glass fibers should be alkali-resistant to avoid being damaged by
the concrete. In general, the strengthening fibers may consist of
any fibers with high tensile strength that can bond with the
concrete without being chemically degraded over time.
[0072] While the exact formulation of the mixture is somewhat of an
art due to variations in temperature, humidity, shape of the panel,
etc., the above formulations are generally used. The following
additions, however, may be made to achieve certain goals, such as
adding an acrylic polymer to control the curing time of the panel
mixture in an amount of about 5 to 10 percent by weight of the
liquid component.
[0073] Likewise, a super plasticizer can be added to control the
flowability of the panel mixture during the pouring process into
the vertical mold cavity. Generally, a preferred range for adding
the super plasticizer is in an amount of about 1/2 to 8 ounces per
94 pounds of cement in the solids component.
[0074] Also a concrete extender may be added to the liquids
component to control the setup of the panel mixture due to
temperature in an amount of about 1/2 to 2 ounces per 94 pounds of
cement in the solids component.
[0075] It has also been found that adding an anti-foaming agent to
the liquids component in an amount of about 1/4 to 3/4 ounces per
94 pounds of cement in the solids component controls and prevents
the creation of voids in the molded panel.
[0076] Step 4: Filling mold cavity 34 with the prepared panel
mixture and leveling the panel mixture with the mold side edge
walls to fill all voids in the mold cavity 34.
[0077] Step 5: Effecting the cure of the poured panel mixture in
mold 32 and the bonding of the mixture to foam insert 12; and,
[0078] Step 6: Removing the integral assembly of cured panel
mixture and foam insert 12 from mold cavity 34.
[0079] While the above 6 steps may be sufficient to embody the
present invention, it is preferred to add additional steps that
further embody the present invention as the following:
[0080] Placing selected details on the top, bottom and sides of the
mold cavity to shape the panel mixture at the side edges of the
molded wall panel to form desired channels in the panel edges. This
is best illustrated by the bottom detail 46 shown in FIG. 7 placed
in the bottom 38 of the mold cavity, and the formed channels that
appear in the sides of the molded panel in the other FIGS. These
channels are useful for creating the bonding joint discussed
elsewhere above for joining two adjacent panels, and for forming
the horizontal concrete beam across the tops of panels during
construction of the building.
[0081] Also, it is preferred that a step be added of spraying the
mold cavity with a mold release to facilitate the removal of the
integral assembly of cured panel mixture and foam insert from the
mold cavity once it has cured.
[0082] As was mentioned above, it is necessary that the foam insert
be held in the mold cavity in a known and secure position during
the pouring process as the hydrostatic pressures created during the
pouring process will try to float and warp the foam insert. One
preferred method of securing the foam insert in the mold cavity is
embodied in the following step which is illustrated in FIGS. 11 and
12:
[0083] Inserting, on opposite sides of the foam insert when it is
positioned in the mold cavity, spacing fingers that are
intermediate the sides of the foam insert and the mold cavity walls
for keeping the foam insert centered in the mold cavity and
preventing the foam insert from moving and warping as the mold
cavity is filled with panel mixture.
[0084] It is further preferred, during the pouring process, as the
mixture rises to fill the mold cavity, to perform a step of:
[0085] Withdrawing the spacing fingers gradually from the mold
cavity as the panel mixture fills the mold cavity, and bonds with
the foam insert. The panel mixture sets up enough to hold the foam
insert in position as the spacing fingers are withdrawn.
[0086] Also, to prevent the foam insert from "floating" during the
pouring process, it is preferred that a step be added to the
process of:
[0087] Providing hold-down members, mounted on the mold, held down
against an upper exposed edge of the foam insert, to hold the foam
insert in position and prevent it from floating upwards while
filling the mold cavity with the panel mixture.
[0088] As with the spacing fingers, the hold-down members should be
removed from contact with the foam insert as the panel mixture
fills the mold cavity and begins to flow over the top of the foam
core.
[0089] It is further preferred that a vibrator 48 be mounted on the
mold 32, as illustrated in FIG. 6, for helping to spread uniformly
the panel mixture in the mold cavity 34 by enhancing its
flowability. A low frequency of vibration is preferred to agitate
the panel mixture to eliminate voids in the poured panel.
[0090] Another step to eliminate or at least lessen the possibility
of voids forming in the panel is to add a step of:
[0091] providing a vertical channel in the foam insert to allow
rapid and uniform filling of the mold cavity. Actually a number of
channels to help the uniform spread of the panel mixture as it is
poured into the mold cavity can be cut into the foam insert.
Cutting at least one vertical channel in opposite sides of the foam
insert (as illustrated by the channels 76 in FIG. 8) to allow rapid
and uniform filling of the mold cavity is one such example of
providing such channels.
[0092] It has also been found that from both an economic and a
mechanical standpoint, it is preferred that the vertically oriented
mold be provided with two, adjacent mold cavities sharing a common
wall as shown in FIGS. 6 and 7. This configuration not only makes a
more efficient use of floor space by providing a smaller
manufacturing "footprint" for the mold while simultaneously making
two panels, but the common wall vertical configuration also lessens
the large hydrostatic forces applied on the mold cavity walls by
allowing at the least the forces along the common wall to cancel
one another by acting in generally opposite directions. Of course
for this to be effective, both mold cavities must be filled at the
same rate to allow equal, but opposing forces to develop against
the common wall in each mold cavity.
[0093] While the panels described so far have a flat or planar
configuration, it is also within the scope of the present invention
to produce panels of varying configurations and shapes. For
example, FIG. 8 illustrates a curved mold 70, as viewed from above,
for use in forming curved panels as for a turret structure. Unique
molds would be made for each required radius of curvature. The
figure shows the edge details 72 in place and the pre-curved foam
core 74 inside the mold 70. Note that this foam core 74 shows the
V-shaped channels 76 that run vertically to facilitate pouring the
GFRC mixture, letting it flow freely to the bottom of the mold. The
curved black bar 78 is the bar that holds the foam down during
pouring of the GFRC, and the black cross pieces 80 are the metal
pieces that hold bar 78 in place during the pouring process.
[0094] Likewise, as shown in FIG. 9, the mold cavity 82 used to
produce such panels may have internal spacers/dividers 84 inserted
to form multiple small panels at the same time in one typical mold
cavity 82. Window and door headers are good examples of small
panels that can be molded this way. Such spacers/dividers make the
molds more versatile, so most molds can be made in a standard
overall size and shape, yet can be used for making any of the
smaller sized panels with only a minimum modification.
[0095] Also for greater versatility, FIG. 10 illustrates the lower
part of a double mold 86, showing that the bottom plate 88 can have
multiple slots 90 for receiving the bottom edges 92 of the outer
mold faces 94. This configuration allows one mold to be used to
create panels of several different thicknesses. The bottom edge
detail insert 96 is shown, making it clear that it covers one of
the slots 98, preventing it from filling with GFRC during the
pouring process. This makes each mold unit more versatile, letting
each one be used for multiple panel thicknesses, e.g., 4.5", 6.5",
and 8.5". Note that it is also useful that the side walls 94 can be
completely removed, facilitating removal of the molded panel once
the GFRC has cured. It would also be possible to hinge the outer
faces at the bottom, so each face could be rotated outward on its
hinges. This would be an alternate means of facilitating the
removal of completed panels, but would not lend itself to different
thicknesses of panels. The most preferred embodiment would utilize
the slots.
[0096] FIGS. 11 and 12 show the spacer "fingers" 100 used to hold
the foam core 102 at precisely the right separation from the mold
faces 104. The number of fingers and the width and thickness of
each can obviously be varied in many ways.
[0097] These spacing fingers are gradually raised as the GFRC
gradually fills the mold cavity, so that the fingers are usually
kept just above the top surface of the GFRC mixture. The fingers
are totally removed when the GFRC reaches the top of the foam. At
that point, the top hold-down bar can also be removed, and then the
last bit of GFRC can be added and the top edge detail can be
pressed down into the GFRC at the top of the mold to form the
desired channel or edge detail of the panel.
[0098] It is also possible to connect the fingers at their top ends
so that two or more of them can be manipulated as one unit.
Preferably, if the fingers are to be joined for manipulation as a
unit, the fingers should be placed in pairs, with each one attached
to the one facing it on the other side of the foam, and a simple
block connects them. In principle, all the fingers could be
connected using a beam across the top of the mold so that they
could all be lifted at once.
[0099] Finally, the foam core must be kept at the desired distance
above the bottom detail to allow the right thickness of GFRC at the
molded bottom edge of the panel. This is important as the foam core
will tend to float up as the GFRC is poured into the mold cavity,
so it may be enough to place the top plate at the right height, so
the foam core will be about 1/4" above the bottom detail when the
core is in contact with the top plate. However, it is preferred to
insert some very small spacers in the foam core at the edge that
will be on the bottom edge of the mold. These can be little
nail-like metal rods with a shoulder so they stick out about 1/4"
from the foam core surface into which they are placed. With a few
of these in the foam core, they hold the foam core in the desired
position vertically from the start of the molding process. These
spacers need not resist much force, since the GFRC tries to float
the foam core. So the main structure for vertical placement of the
foam core in the mold is the top plate or bar which is precisely
positioned and only removed after the GFRC has totally enclosed the
foam core and has set sufficiently to hold the foam core in
place.
[0100] Therefore, the foregoing is considered as illustrative only
of the principles of the invention. Further, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described, and accordingly,
all suitable modifications and equivalents may be resorted to,
falling within the scope of the invention.
* * * * *