Note: Descriptions are shown in the official language in which they were submitted.
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BUILDING PANEL
FIELD OF THE INVENTION
This invention relates to precast building panels and in particular to a
building panel formed of a light-weight cementitious material having light-
s weight metal channel members embedded therein.
BACKGROUND OF THE INVENTION
There has long beezi a need for a building panel of the precast variety that
would be extremely light in weight and having a high tensile strength. One of
the
purposes of such a panel would be to utilize partially embedded channel
members
therein for the subsequent fastening of interior f'mishing materials such as
wallboard and the like. However, in the past, the attempted use of light-
weight
metal channels, for example "C"-shaped channels, embedded in regular concrete
has failed to achieve commercial success. The main problem with panels
resulting from the previous attempts at their production has been that regular
concrete would, by nature of its own weight, overcome the physical properties
of
light-weight metal channels embedded therein and would render them useless
when viewed as an integral structural element in the panel being created. In
reality, the addition of "(.'"-shaped channel members and a regular concrete
mix
actually created more pr«blems than it solved as additional steel reinforcing
and
wire mesh would be required to supply the necessary structural integrity of
the
panel due to a weak section created by the embedding of the channel member in
a
thin layer of concrete. The concrete was necessarily thin, two inches being
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typical, so as to create a benefit of "light-weight" which was the very reason
for
the creation of the panel.
There have been numerous attempts at providing a precast building panel
with structural members embedded therein. Some examples may be found in
European Patent 0 434 869 B 1. This patent discloses the anchoring of metal
studs in a precast concrete building panel.
U.S. Patent 5,178,941 discloses a composite material of a weight lighter
than concrete.
U.S. Patent 4,774,794 discloses the embedding of members in a foam
cement slab.
U.S. Patent 4,910,076 discloses a cement matrix reinforced with a fibre
network.
Other patents of interest are L1.S. 5,248,549; 5,473,849; 4,124,669; and
5,520,729.
SUMMARY OF THE INVENTION
In addressing the short comings of the prior art, some examples of which
are referred to above, the present invention is the result of a need to create
a.
viable, light-weight panel system that would succeed in the broad use of the
commercial market place. One of the objectives of the present invention was to
use readily obtainable construction materials and methods to produce a light-
weight cementitious material with a higher tensile strength then regular
concrete.
This was accomplished by creating a reinforced building panel with two
uniquely
different elements for the required strength and lightness of the product.
For a cementitious material, we use a fibre-reinforced cellular concrete
mixture sold under the trade name Herculete. 'This material is the result of a
composition of portland cement, water, synthetic fibres and an expanding
agent.
A firll description of this material may be found in United States Patent
5,397,516
of 14 March 1995. We have found that by using the fibre-reinforced cellular
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concrete, it is possible, using the correct proportions, to achieve a concrete
product which will resist tlue most common tensile stresses in low-rise
structures.
The resulting weight of the product is approximately 26% of the weight of
regular concrete. This cementitious material is tough and light. Unlike
ordinary
concrete, it has a light-weight closed cell structure that is micro-reinforced
with
uniformly distributed synthetic fibres. It can be used in virtually any
precast
concrete application.
As is known, ordim~y concrete is made with cement and aggregates,
typically crushed stone used as tillers. 'The Herculete material eliminates
the
fillers, reinforces the cenuent with fibres and expands it with uniformly
dispersed
air cells. The air cells give it superb insulating properties, convenient
lightness
and easy usability. The material is made from commonly used time-proven
building materials such as aluminum, calcium, magnesium and silica and the
expanding agent is made from commonly used materials. The cementitious
material is easy to mix and can be handled and molded like ordinary concrete,
it
can be used in place of ordinary concrete in most precast applications and the
resulting products are tough. light-weight and easy to cut and shape.
The composition of the cementitious material (Herculete) is portland
cement, water, synthetic Blares and the expansion agent. '),he plain cement is
the
main component and different types of cement can be used to achieve desired
aesthetic and physical characteristics.
Plain water is used to hydrate the cement and prepare the slurry paste that
subsequently expands to twice its initial volume.
A special blend of synthetic fibres are added to the slurry. These have
been used for years to rein:f'orce ordinary cement but the 1-lerculete
cementitious
material uses ten times as much fibre as commonly used to reinforce concrete
slabs. The manufacturing process results in approximately two thousand
reinforcing strands per cubic inch of material. 'This is one of the factors
which
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gives the material its characteristic toughness and resilience. Synthetic
fibres, for
example, polypropylene fibres, are inert and harmless.
The expansion agent is mixed into the water/cement slurry at high
speeds. Following a short dormant period the cement slurry begins to rise,
much
like bread dough rises when the yeast is added. 'the composition of the
expanding agent creates a Controlled and sustainable rise in the slurry until
it
hardens.
The fibre reinforced cellular concrete used in this invention has a
homogenous nature so that the thermal resistance of the material is consistent
throughout. This means that the R-value of the material is constant and the R-
value used in calculations for thermal transmissions are not reduced to
thermal
bridging as would be found in most common wall construction. Because the
material is composed mainly of concrete, its heat capacity allows it to store
energy for later release similar to more massive wall assemblies. This
translates
to higher effective R-value per inch (R-2, ASHRAE 90.1) then would be
determined using typical steady-state test methods.
rChere is an economic advantage to using this cementitious material as it
allows walls to be assembled in one piece rather than having to build a wall
in
layers as in conventional sandwich panel construction methods and in most
cases
allows for form stripping and panel removal a mere six hours after being
poured.
This translates into faster construction time and lower construction costs for
the
building owners.
The material may be clad with a regular or coloured face mix or
alternatively may remain exposed, utilizing just about any form liner,
shape/design desired, then ~;:oated with an elastomeric paint which offers
unlimited colour choice and control, various textures and with durability and
ease
of maintenance in mind.
As mentioned earlier, the present invention provides a reinforced concrete
panel with two uniquely different systems for the required strength and
lightness
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of the product. 'The first system is the approximately 2000 micro-fibre per
cubic
inch in a matrix of cement and water which forms a microscopic enclosed cell
structure that is capable of resisting the movements of the second element.
The second element consists of a light-weight galvanized channel that has
been altered to provide slot or perforations along its web section to
accommodate the passage of the liquid cementitious material in the
manufacturing process then later to provide for the passage of electrical,
mechanical and/or plumbing components in the field. 'The two elements of the
invention are weak and flexible on their own, in comparison to a regular
concrete
assembly, but when brought together and in combination, one element
restraining
the movement of the other, a very strong light-weight panel is the result. The
components are economic and are ideal for mass production for use in general
construction of all types.
Given the excellent thermal characteristics of Herculete and the fact that it
will take about any shape, provides an opportunity to create a panel for a
residential wall system (as well as commercial and industrial wall systems)
using
a formliner that by its o~~n design and texture provides for the exterior
finish of a
structure. A thermal break between the "outside conditions" and the embedded
"C" channel and the thickness of the Herculete dictates the thermal resistance
as
required by specification or code.
In a two story residential application the vertical wall panel (plain exterior
finish by example) is simply rotated to the horizontal plane and becomes an
ideal
lintel or floor system. Thls system provides for a squeak proof, sound
deadening,
flooring system that is attached to both the lower exterior and upper exterior
wall
by a unique system that leas been created for the specific purpose. Through
testing, this floor system has been proven to carry the necessary residential
loads
over typical spans with acceptable deflections.
A channel system of varying lengths is used and anchored in the top of
the lower exterior walls at varying stages along that surface. They are
unique, in
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that by design, the channel will accept a "T" bolt that when rotated 90
degrees
will restrain that bolt from the vertical forces but allow (until tightened)
movement along its length for proper alignment with the other (floor and upper
exterior wall) components that, by design, are held together to meet the most
stringent codes with one effort. The uniqueness of this device is that when
molded into the Herculete and "C" channel panel during the manufacturing
process it can be used as a lifting point for the efficient handling of the
panel
assembly in the manufacturing plant, during transportation, and as part of the
erection-on-site process. Further, by design, this connection system allows
for
the safety of the lower exterior walls and the floor system to be connected
(irrespective of the upper wall placement) to produce a rigid, safe system.
According to one broad aspect the invention relates to a building panel for
use in a wall structure, said panel comprising a body of predetermined
thickness
of hardenable cementitious material in combination with a plurality of light-
weight metal members arranged and partially embedded in said cementitious
material, said cementitious material comprising a fibre-reinforced, expandable
cellular concrete-like substance having a weight substantially less than that
of
conventional concrete, a portion of said light-weight metal members projecting
from said body of cementitious material to provide structural surfaces ready
for
reception of finishing surfaces or the like and to provide recessed areas
between
the surface of said cementitious material an said structural surfaces to
facilitate
the accommodation of insulation, services, systems and the like, said light-
weight
metal members including means to engage and interconnect with said hardenable
cementitious material to provide mutual strengthening of said combination of
cementitious material and said metal members in said building panel.
According to a further broad aspect, the invention relates to a method of
making a building panel for use in a wall structure, said method comprising
the
steps of preparing a slurry-enclosing form of predetermined depth; preparing a
slurry of hardenable cementitious material comprising portland cement, water,
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synthetic fibres and an expansion agent and pouring said slurry into said form
to
a predetermined depth positioning a plurality of light-weight metal members in
said form and to a predetermined depth therein; and allowing said slurry to
expand and harden into a light-weight, closed cell material and engaging a
portion of said metal members and leaving another portion thereof to provide
structural-fastening surfaces for said building panel.
DESCRIPTION OF THE DRAWINGS
The invention is illustrated by way of example in the accompanying
drawings in which:
FIGURE 1 is a plan view of a building panel according to the invention;
FIGURE 2 is a side view of the panel in Figure 1;
FIGURE 3 is a sectional view of the panel in Figure 1;
FIGURE 4 is a wall section of a building structure utilizing the present
invention;
1 ~ FIGURE 5 is a fragmentary view in cross-section as shown at location "5"
in Figure 4;
FIGURE 6 is a view similar to Figure 4;
FIGURE 7 is a plan view of a panel reinforcing grid and the weld points
therefore;
FIGURE 8 is a detail of vertical joints between panels;
FIGURE 9 is a sectional view of a permanent forming arrangement;
FIGURE 10 is an elevation view of a junction between an interior wall
and floor;
FIGURE I 1 is a sectional view of an alternate flooring system;
FIGURE 12 is a junction detail of an exterior wall with a floor panel;
FIGURE 13 illustrates a joint at an exterior wall and a footing;
FIGURE 14 is a schematic elevation view of a residential structure;
FIGURE 15 illustrates a wall/roof connection;
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FIGURE 16 illustrates a residential wall in section;
FIGURE 17 is another residential wall in section but of an upper level;
FIGURE 18 is a cross-sectional view of a residential wall/floor panel
connection;
FIGURE 19 is a perspective view thereof;
FIGURE 20 is a graph showing the expansion process of the cementitious
material;
FIGURE 21 is a partial elevation view of a sound attenuation walls; and
FIGURES 22 and '23 are plan and sectional views thereof.
DESCRIPTION OF THF; PREFERRED EMBODIMENT
Figures 1-3 illustrate a building panel 10 according to the invention for
use in a wall structure of a dwelling, commercial building or the like. The
panel
10 has a body 12 of the cernentitious material :Elerculete in accordance with
the
invention and a plurality of light-weight metal studs 14 are embedded into the
cementitious material during the :processing steps and those members 14 have
an
exposed flange 16 which, collectively, are ready for reception of finishing
wall
board or the like. In the example shown in Figure 2, the panel has an 8 inch
depth of cementitious Herculete 12 and a 2 '/2 inch face mix 18.
Figure 4 is a wall section of the building panel 10, a twist and lock plate
20 being used in an embedded anchor socket 22 for the connection between a
panel 10 and a beam 24.
Figure 5 shows a section through the line 5-5 of Figure 4 and illustrates a
drywall panel 26 secured tc> the projected portion 16 of stud 14.
Figure 6 shows the relationship between an upper wall panel 28, a beam
30 and roof panels 32.
Figure 7 shows a panel reinforcing grid of metal studs 14 which are
equally spaced at 16 inch centres across the panel. Anchors 34 are embedded 6
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inches into the cementitious material 12. Studs 14 are suitably secured to
upper
and lower tracks 36, 38 respectively.
Figure 8 provides <~. detail of a vertical 'joint between two panels 10a and
l Ob. Panel 10a has a channel 40 along one of its marginal edges and that
channel
receives a tongue 42 on the marginal side edge of the adjacent panel 10b. The
joint is roped and caulked as indicated at 44 on the outside of the joint.
Figure 9 shows a permanent forming arrangement where precast concrete
joists 46 have Herculete panels 48 extending between pairs of the joists 46.
The
joists 46 are placed in position and the Herculete light-weight precast panels
48
are placed in position therebetween the concrete joists and a normal weight
structural, reinforced concrete topping SU is installed on the upper surface
of the
joist 46 and Herculete 48. In this manner, the Herculete "forming" remains in
position and provides a concrete appearance.
Figure 10 shows a junction between an interior wall panel 10 connected to
a Herculete floor panel 52. This connection is made by way of the welding
together of two joining plates, one of which 54 is embedded in the Herculete
floor panel 52 and the other member 56 being anchored in the upper end of the
wall panel 10. Temporary access pockets 58 are provided for welding of the
facing plates 60a and 60b of' the members 54 and 56 and these access pockets
are
subsequently filled with plaster following inspection.
Figure 11 shows an alternate flooring system where an upper floor is
formed by a Herculete panel 62 and the embedded metal studs 64 have projecting
portions 66 to which drywall ceiling 68 is secured. The projected portions 66
creates a space between the drywall ceiling and the lower surface of panel 62
through which conduits and the like may be run.
Figure 12 shows a connection or junction between an exterior wall 70 and
a floor panel 72. Weld plates 74, 76, 78 and 80 are embedded in their
respective
locations to provide welding sites such as 82 and 84.
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A joint between an exterior wall 86 and a footing 88 is shown in Figure
13. Again, weld plates are embedded in the exterior wall at 90 and 92 for
welding to adjacent, embedded weld ,plates 94, 96 in the footing.
Figure 14 is a schematic of a residence which comprises a plurality of
Herculete panels 10.
Figure 15 shows a wall/roof connection where the wall panel 100 is
connected to a steel uplift strap 102 by way of a unit strut 104 embedded in
the
upper end of panel 100. An alignment and locking plate 106 is located between
the joints in the panels.
Figure 16 is a cross-section through a residential wall showing the panel
110 having the exposed metal studs 114 embedded in the Herculete cementitious
material 112. The wall 110 is channelled to received a floor panel 116 which
also has exposed metal studs 114 embedded in the cementitious material of the
floor panel.
The wall panel 1 l0 is located on a footing 118 pravided with anchor bolts
120 to which the metal stud members may be fastened. Such an arrangement
lends itself to very quick erection and the studs 114 are ready and placed to
receive drywall.
Figure 17 is an upper extension of the Figure 16 illustration and shows the
uplift strap 102 previously illustrated in Figure 15 used here to locate the
upper
part of wall panel 110 to its proper location with a wooden truss 122. The
lower
end of the strap 102 is received in the anchor box 124 embedded in the upper
end
of wall panel 110.
Figure 18 is a crass-section through a residential wall/floor panel, the
upper wall 111 being joined to the lower wall 'l 10 through the combination of
an
anchor sleeve 126 embedded in the upper end of the lower wall 110 which
receives one end of an anchor bolt 128 having a twist-and-lock head 130
thereon,
that head being received in the anchor sleeve 126. The anchor bolt 128 passes
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through a slot 132 provided in the floor panel, as shown in Figure 19, and a
pocket 134 is provided in the floor panel to receive a spreader plate 136.
At the upper end oi' the connection, a metal angle 138 is embedded in the
upper wall panel 111 and the overall connection is secured in place by a nut
140.
Figures 21, 22 and 23 illustrate a highway sound attenuation barrier made
from panels in accordance with the material disclosed by the present
invention.
As shown in Figure 21, a plurality of panels 1 ~0, 152 and 154 are located on
top
of one another with their r~iarginal edges engaging one another. The end
portions
of each of the panels are formed to slideably engage a steel post 156 and a
cap
portion 158 engages the upper end of the post and is large enough in area to
also
cover small face panels 1.60 that overlie the connections between the aligned
ends
of the panels and the post itself. This provides for a light-weight, affective
sound
attenuation wall.
Figure 20 is a graph showing the expansion process of the cementitious
material Herculete used in the present invention. Due to the composition of
the
cementitious material, its heat capacity allows it to store energy for
subsequent
release. This translates to <in insulation value of R2 per inch whereas normal
concrete has an insulation value of 8.017 per inch. This insulation
characteristic
makes the substance ideally suited as an energy efficient material for
residential
and commercial construction.
The panels utilizing the cementitious material of the invention permits
removal of the finished product from its form work within a six hour period
whereas normal concrete re~,quires twenty-four hours. This greatly enhances
productivity.
It will be appreciated that form liners can be used in the process to
provide a variety of finishes such as stucco, brick, fluted block, etc.
Colours can
also be added to the mix. A number of products can be made utilizing the
cementitious material. These include residential floor systems to replace
existing
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wood joist and plywood sheeting and by means of which the flooring is fire
resistive and provides sc}und attenuation.
Residential and commercial exterior wall systems to replace the time-
consuming, conventionally layered concrete brick or stucco exterior backed by
studs, insulation and vapour barrier.
Commercial roof systems; precast sandwich panels, spandrel panels,
modular classrooms, utility buildings, highway environmental sound attenuation
barriers; and common walls and fire walls for residential and commercial
buildings.
While the invention has been described in connection with a specific
embodiment thereof and in a specific use, various modifications thereof will
occur to those skilled in the art without departing from the spirit and scope
of the
invention as set forth in the; appended claims.
The terms and expressions which have been employed in this
specification are used as terms of description and not of limitations, and
there is
no intention in the use of such terms and expressions to exclude any
equivalents
of the features shown and described or portions thereof; but it is recognized
that
various modifications are possible within the scope of the invention claims.
