U.S. patent application number 11/197238 was filed with the patent office on 2007-02-08 for prefabricated shell concrete structural components.
Invention is credited to Mark Joseph Pasek.
Application Number | 20070028541 11/197238 |
Document ID | / |
Family ID | 37716352 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070028541 |
Kind Code |
A1 |
Pasek; Mark Joseph |
February 8, 2007 |
Prefabricated shell concrete structural components
Abstract
A concrete shell is formed as a mold for substantial concrete
structures. The shell includes an interior mesh element that will
be encapsulated in concrete in the poured concrete structure. A
panel of moisture impervious material forms an outer layer of the
concrete shell and acts as a form for field poured concrete making
up a structural concrete element.
Inventors: |
Pasek; Mark Joseph; (Plano,
IL) |
Correspondence
Address: |
DOUGLAS W RUDY;LAW OFFICES OF DOUGLAS W. RUDY, LLC
401 N. MICHIGAN AVENUE
SUITE 1200
CHICAGO
IL
60611
US
|
Family ID: |
37716352 |
Appl. No.: |
11/197238 |
Filed: |
August 2, 2005 |
Current U.S.
Class: |
52/250 |
Current CPC
Class: |
B28B 19/0046 20130101;
B28B 19/0092 20130101; E02B 3/06 20130101; E04C 5/07 20130101; E04G
9/02 20130101; E04C 3/20 20130101; E04C 3/34 20130101; E04C 3/26
20130101 |
Class at
Publication: |
052/250 |
International
Class: |
E04B 1/00 20060101
E04B001/00 |
Claims
1. A prefabricated concrete shell forming a component of a concrete
structural element, the prefabricated shell comprising: a.
concrete; b. an additive mixed into the concrete before the
concrete is cured; c. a panel of fluid impervious material forming
a surface of the prefabricated shell; d. a locator extending from
the panel of fluid impervious material; e. a sheet of mesh fabric
spaced apart from the panel, the sheet located in position by a
locator.
2. The invention in accordance with claim 1 wherein the additive
comprises a reactive pozzolan.
3. The invention in accordance with claim 1 wherein the additive
comprises silica-fume.
4. The invention in accordance with claim 1 wherein the additive
comprises ground granulated blast furnace slag.
5. The invention in accordance with claim 1 wherein the sheet of
mesh fabric is a carbon fiber mesh grid.
6. The invention in accordance with claim 1 wherein the panel of
fluid impervious material comprises a substantially non-metallic
membrane.
7. The invention in accordance with claim 5 wherein the sheet of
mesh fabric is nonmetallic.
8. The invention in accordance with claim 5 wherein the sheet of
mesh fabric is oxidation resistant.
9. The invention in accordance with claim 5 wherein the sheet of
mesh fabric is carbon fiber.
10. The invention in accordance with claim 1 wherein the panel of
fluid impervious material is fiberglass.
11. The invention in accordance with claim 1 wherein the panel of
fluid impervious material further comprises a resin coating.
12. The invention in accordance with claim 1 wherein the locator is
nonmetallic.
13. The invention in accordance with claim 1 wherein the locator is
substantially nonmetallic.
14. The invention in accordance with claim 12 wherein the locator
is attached to the sheet of mesh fabric and to a panel of fluid
impervious material.
15. A method of making a prefabricated shell comprising the acts
of: providing a mold, the mold being a surface wherein the
prefabricated shell is molded; providing a panel of fluid
impervious material comprising an interior surface; positioning
locators proximate the panel of fluid impervious material of the
form; providing a sheet of mesh fabric and locating the sheet of
mesh fabric proximate the panel of fluid impervious material of the
form; placing the panel of fluid impervious material, locators and
sheet of mesh fabric in the mold; pouring concrete into the mold,
whereby the sheet of mesh fabric and the locators are surrounded by
concrete and the concrete contacts the interior surface of the
panel of fluid impervious material.
16. The method of claim 15 further comprising the act of curing the
concrete in the mold to form a prefabricated shell.
17. The method of claim 15 wherein the concrete comprises reactive
pozzolan as an additive to the concrete.
18. The act as set forth in claim 15 further comprising the acts of
connecting a locator to the fluid impervious material and
connecting a locator to the sheet of mesh fabric.
19. A concrete structure comprising; prefabricated concrete shell
forming a component of a concrete structural element, the
prefabricated shell comprising: concrete including an additive
mixed into the concrete before the concrete is cured; a panel of
fluid impervious material forming a surface of the prefabricated
shell; a locator extending from the panel of fluid impervious
material; a sheet of mesh fabric spaced apart from the panel, the
sheet located in position by the locators; a core of concrete
located inside the prefabricated concrete shell, the core of
concrete adjacent the panel of fluid impervious material, the core
of concrete having an additive mixed into the procured concrete,
the additive in the concrete being of a lesser amount by percentage
than the additive used in the concrete of the prefabricated
concrete shell.
20. The invention in accordance with claim 21 wherein the additive
is silica-fume.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is an original application not related to any other
applications.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention is directed to forms used for in situ casting
of concrete products such as, but not limited to piers, columns,
beams and concrete elements of highway overpasses, long span
bridges, docks and piers, train bridges, parking garage structures,
raised streets and highways and similar large structural
components.
[0004] 2. Description of Related Art
[0005] No concrete structures using the type of prefabricated
shells presented in this disclosure, having the configuration of
components herein disclosed or relying on the method used in making
structures as taught herein, are known. There exists concrete forms
for making structural concrete components and there are concrete
forms that are precast, shipped to a construction site, and then
filled with concrete on site. U.S. Pat. No. 6,189,286 B1 discloses
a fiber tube that is formed at a remote manufacturing location and
shipped to a construction site. The fiber form is then filled with
concrete at the site. The form, being of fiber reinforced material,
has advantages, such as impermeability to water and chemicals,
however the completed product is different from the structure
presented herein in that in the known invention, the fiber
reinforced form becomes the exterior surface of the finished
product. In the invention herein a fiberglass panel becomes the
inner panel of a shell and the shell is then filled with concrete.
Thus the fiberglass panel is encased in concrete in the final
configuration. Another patent disclosing a form for concrete
filling at a construction site is shown in U.S. Pat. No. 3,678,815.
This patent discloses a precast, field-filled structure, however,
even this patent does not disclose the invention set forth herein.
For instance, the '815 patent teaches away from the instant
invention in that it discloses a structure that has two clamshell
like premolded shell pieces, which are assembled one-to-the-other
at the jobsite, rather than the single prefabricated shell mold
that is disclosed herein. Furthermore, the '815 patent teaches the
use of welded mesh wire fabric in the field filled structure. This
is contrary to one object of this invention, that being that the
completed structure is designed to avoid, or at least to minimize,
the use of ferrous metal products that will oxidize and cause
deterioration of the structure.
[0006] U.S. Pat. No. 5,032,197 discloses a manhole repair technique
where a plastic liner is spaced away from a deteriorated wall
surface of the manhole. Concrete is poured into the zone between
the old wall and the liner. The liner may be held in place by
interlocking T-ribs until the concrete is poured. This is not a
system for the manufacture of a prefabricated shell structure that
is eventually filled as is taught by this disclosure.
SUMMARY OF THE INVENTION
[0007] The idea presented herein is apparatus and a method of
casting major structural components out of concrete. The apparatus
is a structure that is manufactured in a controlled environment and
then shipped to a final location where the structure is permanently
placed and subsequently filled with a concrete mix to form a
structural component of significant size. The manufactured precast
or prefabricated structure, referred to as shells or prefabricated
shells in this disclosure, is both the form for containing the
significant mass of concrete provides load supporting and bearing
strength to the finished structure and a structural portion of the
final structural product such as pier, column, arch, bend cap,
bridge, elevated roadway support, and the like.
[0008] The prefabricated shells will use a carbon fiber mesh grid,
or welded wire mesh grid equivalent, instead of a conventional
welded wire mesh grid. The preferred embodiment of the invention
will not incorporate steel or any other materials susceptible to
corrosion in the precast concrete components. Even epoxy or plastic
coated steel mesh grid is subject to corrosion if the epoxy coating
is compromised, which is easily done in handling and positioning of
a welded wire mesh grid. A carbon fiber mesh grid is chemically
inert and non-corrosive.
[0009] The carbon fiber mesh, being inert, is not subject to
corrosion, can be positioned in the prefabricated shell close to
what will become the outer surface of the shell. This will reduce
surface cracking of the shell as the reinforcing carbon mesh will
be closer to the outside surface than is practically possible in a
formed-in-place concrete structure of a conventional reinforced
structure where the reinforcement elements, the rebar, for
instance, cannot be too close to the surface as it would be subject
to moisture penetration and ultimately oxidation and rusting of the
metal reinforcement elements. In the case of the prefabricated
shells themselves the carbon mesh will provide structural strength
to carry the dead load of the unfilled prefabricated shells as the
shells are being transported from the production factory to the job
site where the prefabricated shells will be filled with
concrete.
[0010] One technique of on-location filling and pouring of concrete
structures involves the well-known use of wooden or metal forms.
The forms are installed at the site, the concrete is poured into
the forms and after the concrete cures the forms are removed and
trucked to storage for a subsequent use. There are significant
costs in the transportation of the forms, the erection of the forms
and the removal of the forms. The development herein provides a
method of pillar and beam construction that reduces the use of
temporary formwork and thus the labor costs to transport, position
and remove the temporary forms.
[0011] It is the inventor's intention to provide a system that is
used to create structural concrete elements such as bend caps,
beams, piers and columns, wherein the finished products are
impervious to the effects of chloride-ion migration, internal steel
corrosion, imperviousness to the effects of alkali-silica
reactivity, and the effects of freeze-thaw cycles in cold climates.
The resulting structure will resist detrimental expansion and
contraction effects and surface cracking of the completed column or
beam. For instance, since the prefabricated shell includes a
fiberglass or, alternatively, a high-density polyethylene (HDPE)
panel comprising the inner surface of the shell, it can be
configured to provide a mechanical bond between itself and the
concrete poured into the shell at the job site. This is
advantageous as the shell is now somewhat a sacrificial barrier to
absorb abuse from impacts on the finished structure. In actual use
the prefabricated shell can deteriorate from external contamination
or it can be destroyed by impacts. However, the inner wall, the
fiberglass panel for example, and the core concrete structure will
stay intact. The prefabricated shell is thus repairable or
resurfaceable without the need to replace or repair the core
concrete structure. Furthermore, the repair can be made without
compromising the corrosion protection provided by the inner wall
structure.
[0012] Another feature of concrete structures using the techniques
of the prefabricated shells set forth herein, is that the structure
can accommodate different rates of thermal expansion, contraction
and deflection between the interior concrete core, that core being
poured at the job site, and the prefabricated shell which usually
be fabricated at a remote location.
[0013] By using a system where the forms are prefabricated shells,
and by using silica-fume additives discussed further on in the
manufacture of the prefabricate shells, the prefabricated shell as
well as the final concrete structure is resistant to load transfer
fracturing. This and some of the advantages set forth above and in
the following specification provides a method of construction and
an actual structure that has a longer life cycle and a higher
structural integrity than conventional methods of forming completed
concrete structures.
[0014] An advantage of using the additive, such as silica-fume, in
the prefabricated shell, rather than in the entire concrete
structure, is that the overall cost of each structure can be
reduced as the additive need only be mixed into the prefabricated
shell, not mixed into the concrete of the entire column, in order
to yield the results desired from this invention.
[0015] In conventional on-site form filling the forms are not
normally part of the structure. They are simply containment
barriers that are removed once the concrete has been poured and
cured. Since the conventional forms don't make up part of the
completed structure the amount of concrete poured into a
conventional form system for a similar sized component is greater
than the amount of concrete poured into the prefabricated shells
taught by this disclosure. This is significant conventional forms
are limited by the volume that they can accommodate before
"blowing" out. For instance, a four foot diameter conventional form
for a column can only be made about twenty feet tall. If it is
filled in one pour the form will be approaching its ability to
maintain its integrity without blowing out. The conventional form
can have auxiliary shoring and bracing but this adds cost and time
in to the assembly and disassembly of the conventional form. Thus
the number of lift limitations, a "lift" being when forms are set
up, poured, cured, stripped, and moved and set up again, is
partially determined by the temporary framework's capacity and the
complications in forming a base, integrating it with a pier or
column, and then to a bent cap. To make a forty foot tall column
two lifts of twenty feet each would be needed. Also, there is an
economic limit of providing temporary formwork for the entire
structure at one time without reusing forms. For these, and other
reasons known in the industry, this means that there are a limited
number of lifts for a large structure. A large number of lifts may
yield a higher percentage of cold joints in the completed
structure. With this invention the number of lifts is reduced
significantly as the prefabricated structures can be stacked on top
of each other, for instance a twenty foot column form can be
stacked on a twenty foot column form making a forty foot column
that can be poured in one pour without blowing out the
prefabricated shells.
[0016] Since the prefabricated shell is formed at a factory site
curing conditions can be controlled carefully by the fabricator.
The shell curing cycle is observable, testable, predictable and
therefore engineerable to ensure a consistent and uniform
prefabricated shell. The system presented here is more efficient in
that the forms are made of the prefabricated shells, there is no
need to transport and manipulate removable forms and the resulting
product is impervious to water intrusion and the attendant
corrosion and structural deterioration.
[0017] An object of the invention, in addition to the objects and
advantages set forth above, is to provide a method of forming a
prefabricated shell, and the shell itself, that layers protective
elements in a way that is not done in the industry. The layering
creates a prefabricated shell and concrete structure that has its
own internal protective layer provided by the mechanical fastening
of a fiberglass layer as part of the prefabricated shell. This
layer becomes an internal barrier in the completed concrete filled
structure.
[0018] One advantage of the structure is that there are sealed
joints between the components that block water, air, and
chloride-ion migration through the joint to the concrete and steel
structure.
[0019] By using the method and the components set forth herein the
resulting structure possesses at least two important advantages
over the art. These include, but are not limited to, corrosion
protection on the exterior of the final concrete structure and
increased compressive strength in the core of the finished product.
It is also advantageous in that the structural steel
reinforcements, such as reinforcement bar ("rebar"), can be
arranged near the edge of the core structure without the risk of
these steel elements being subjected to corrosive elements from
moisture intrusion as there is a fiberglass or plastic barrier on
the inside of the prefabricated shell. By placing the rebar closer
to the outer surface of the structure the efficiency of the
reinforcing bars is increased. This is possible in this invention
as the rebar remains protected from contaminating environmental
elements.
[0020] The above summary does not include an exhaustive list of all
aspects, advantages or objects of the present invention. The
inventor contemplates that his invention includes all systems and
methods that can be practiced from all suitable combinations of the
various aspects summarized above, as well as those disclosed in the
detailed description below and particularly pointed out in the
claims. Such combinations have particular advantages not
specifically recited in the above summary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Various embodiments of the invention, including the
inventor's preferred embodiment, are presented here and are
described below in the drawing figures and Detailed Description of
the Drawings. Unless specifically noted, it is intended that the
words and phrases in the specification and the claims be given the
ordinary and customary meaning to those of ordinary skill in the
applicable arts. If any other special meaning is intended for any
word or phrase, the specification will clearly state and define the
special meaning.
[0022] FIG. 1 is an illustrative elevation view of a precast column
having a portion removed to reveal the internal structure of the
column,
[0023] FIG. 2 is a broken away portion of the exposed interior of
the column shown in FIG. 1,
[0024] FIG. 3 is a sketch of a portion of an prefabricated shell
column from the end of the column,
[0025] FIGS. 4 A-D show three stages in the formation of a tubular
shaped prefabricated shell,
[0026] FIGS. 5 A-D show three stages in the formation of a
rectangular open-topped shaped prefabricated shell,
[0027] FIG. 6 is a truncated cross sectional presentation of a pier
or column,
[0028] FIG. 7 shows a broken away portion of a structural beam
prefabricated shell,
[0029] FIG. 8 is a complete top view of the structure of FIG.
7,
[0030] FIG. 9 is cross-sectional view of FIG. 8 taken through
9-9,
[0031] FIG. 10 is a partial side elevation pictorial representation
showing post tensioning hardware,
[0032] FIG. 11 is an end view of the structure of FIG. 10,
[0033] FIG. 12 is a pictorial representation of a portion of a set
of two interlocking forms,
[0034] FIG. 13 is a pictorial representation of the components of
FIG. 12 post pour,
[0035] FIG. 14 is a representation of a cross sectioned view of a
concrete structure poured monolithically inside prefabricated
shells,
[0036] FIG. 15 is a cross sectioned view of a lid for an open pour
section element,
[0037] FIG. 16 is a cross sectioned view of a portion of a lid and
pour section element.
DISCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION
[0038] In the following figures like reference characters indicate
like components.
[0039] Looking first at FIG. 1, one embodiment of the invention is
shown. In this figure a pier or column, generally 10, is shown with
a portion of the surface removed to show the internal structure of
a completed precast, field-filled concrete column. The outer layer
12 of the column, comprised of concrete, is finished with a smooth
finish. The finish on surface 14 is a smooth metal form finish that
is imparted to the concrete outer layer 12 through contact with the
metal form in which the prefabricated shell is initially cast. The
prefabricated shell 16, as shown in FIG. 1, is generally a hollow
shell tubular structure of any of many cross-sectional shapes, such
as, but not limited to, circular, square, oblong, rectangular,
obround, triangular, multiplanar, or the like, cross sectional
shapes. The prefabricated shell 16 will be filled in the field with
an appropriate concrete as determined by structural parameters.
[0040] In FIG. 2, a broken away portion of the column shown in FIG.
1, the interior details are more readily visible. The prefabricated
shell 16 comprises a concrete shell and cast in the concrete of
this shell is a non-reactive reinforcement grid sheet of material
20 that is located and supported in place by spacers or locators,
one shown as 22. The non-reactive reinforcement grid sheet of
material in one embodiment is a non-metallic, screen-like material
of carbon-based, polymer-based, or plastic derived material, such
as, but not limited to, polystyrene, polyethylene, polypropylene,
or other man-made fibrous spun, extruded or woven products. In
other embodiments it may be advantageous to make the non-reactive
reinforcement grid material, or welded wire mesh grid equivilent,
of carbon tows or naturally occurring materials such as, but not
limited to mineral products, such as silica-based products such as
glass; plant fibers; or even animal fibers. One other embodiment
may rely on the use of metallic content screen, such as stainless
steel or moisture barrier encapsulated steel, each falling under
the general broad term of a welded wire mesh equivalent. Such
metallic content screen would best meet the inventor's intent of
incorporating non-oxidizing materials in the prefabricated shell if
the metallic comprising material were impervious to oxidation due
to moisture or exposure to chemicals.
[0041] One embodiment of the invention contemplates the use of
"C-Grid" Brand Carbon Grid for concrete reinforcement material made
by bonding ultra high-strength carbon tows with epoxy resin in a
controlled environment. This product is available from TechFab, LLC
of Anderson, S.C.
[0042] The spacers, or hereinafter, the locators 22 are attached to
the non-reactive reinforcement grid material 20 at junction 24. The
spacers will assist in locating the non-reactive reinforcement grid
material appropriately in the prefabricated shell 16.
[0043] The interior surface of the prefabricated shell 16, that is,
the surface that will contact the concrete that is poured into the
prefabricated shell in the field, is comprised of a fiberglass
panel 26 with, in one embodiment, a polyester resin surface coat.
The fiberglass panel 26, or as an alternative material, the panel
would be high density polyethylene or other suitable plastic or
polymer material, is generally continuous, although it may have
seams, preferably watertight seams, where a panel will overlay an
adjacent panel, as one of its purposes is to act as an interior
form, as well as an interior structural element of the
prefabricated shell 16. The fiberglass panel may be of
16-ounce/square foot fiberglass or any other weight of fiberglass
material that is structurally appropriate for particular purposes.
As shown in FIGS. 2, 3 and 13, it is desirable to provide surface
features such as protrusions 28 on the interior surface of the
fiberglass panel 26. These protrusions provide mechanical bonds
between the fiberglass panel 26 and the cured concrete that fills
the prefabricated shell in the field. These protrusions 28 can be
of any shape and in an alternative embodiment can be indentations
or a surface pattern that will provide an attachment capability
between the interior of the fiberglass panel and the field poured
concrete. Note that the protrusions in FIG. 13 are "T-shaped" nibs,
a preferred embodiment, different then the protrusions shown in
FIGS. 2 and 3, simply to show that there are different
configurations of protrusions, not just those shown in the drawing
figures, which are contemplated by the inventor. The mechanical
bond between the panel and the poured concrete is desirable, as it
will assist in maintaining continuity between the fiberglass panel
and the field poured concrete and a fluid impervious barrier
protecting the concrete. This is helpful in the event that the
preformed shell is compromised once installed, such as by an impact
from a vehicle hitting a bridge column, or in a less dramatic
situation, by maintenance equipment, such as a mover or a snow plow
blade hitting the base or a column.
[0044] As mentioned above, an alternative to the fiberglass panel
is the use of a high-density polyethylene material (HDPE), or for
that matter, other polymer based products, for the inner wall
structure. HDPE is often used in underground water and sewer
systems as it is lightweight and highly resistant to chemical
corrosive attack.
[0045] The panel 26 functions primarily as a separation layer, both
as a mechanical barrier and as a thermal break or barrier, between
the prefabricated shell and the poured at the job site concrete
core. The panel 26 is not intended to accept structural load
transfer, although it is significant enough to resist the pressure
of the concrete poured around it during the fabrication stage of
the formation of the prefabricated shell. The utility of the
barrier is realized early on at the job site where it helps create
an ideal concrete curing environment by not only providing for an
even temperature during the curing process due to the thermal
break, but also prevents dehydration of the "wet mix" concrete that
is poured into the prefabricated shell at the job site by blocking
water migration from the mix to the prefabricated shell. That is,
without the panel 26, the water in the concrete mix would be
absorbed into the prefabricated shell and thus adversely affect the
cure of the wet mix concrete. This panel 26 creates a protective
envelope around the concrete core and the reinforcing steel
generally positioned in the concrete core. The panel is a barrier
to chloride-ion migration, moisture and air. As mentioned above,
the panel enables the prefabricated shell to be damaged and
repaired, or even deteriorate, without the need of repairing the
concrete core of the pier, column, beam, bent cap, truss, or the
like.
[0046] The locators 22 mentioned above are also attached to the
fiberglass panel 26 such that the locators 22 extend inboard into
the interior of the prefabricated shell and connect to, or locate,
the non-reactive reinforcement grid 20.
[0047] The concrete material of the prefabricated shell, in one
embodiment, is silica-fume four thousand pound concrete. It is
preferred that class-X type four thousand pound or better gray
cement is used in the material of the prefabricated shell.
Silica-fume concrete is a high performance concrete product that is
regular gray concrete augmented through the addition of
silica-fume. Silica-fume, a byproduct of producing silicon metal or
ferrosilicon alloys, is highly resistant to penetration by chloride
ions. It is primarily amorphous silicon dioxide and its particle
size is 1/100.sup.th the size of an average cement particle. It is
a reactive pozzalon (pozzalon is a siliceous or siliceous and
aluminous material that possesses little or no cementitious value.
In a finely divided form and in the presence of moisture, however,
pozzalon reacts chemically with calcium hydroxide to form compounds
possessing cementitious properties.) Concrete containing
silica-fume can have very high strength and can be very durable.
Silica-fume makes concrete watertight and corrosion resistant in
marine applications and de-icing salt applications. Thus its use in
piers, bridge columns, bent caps, bridge spans and other structural
applications exposed to rain, snow, and deicing chemicals along
roadways meets the inventor's objective of providing a
long-lasting, weather resistant and highly corrosive resistant
product.
[0048] Another concrete additive that can be used in the
manufacture of the prefabricated shell is ground granulated blast
furnace slag. This, and the silica-fume additive, are both helpful
in reducing or eliminating the migration of chloride-ions,
moisture, and gas migration to the structural reinforcing members
embedded in the completed structural field-poured elements. These
additives will also create higher compressive strength in the
prefabricated shell.
[0049] The use of the silica-fume or other concrete additive in the
prefabricated shell eliminates the need to use silica-fume
additive, or another performance enhancing additive, in the wet mix
that is poured into the prefabricated shell. This is a significant
cost savings as the additives are expensive and the use of the
additives throughout the entire structure, rather than just in the
shell, does not add significant functionality to the finished
field-poured concrete structure.
[0050] The concrete mixture for the prefabricated shell is,
preferably, a self-compacting concrete mix (SCC).
[0051] The concrete of the prefabricated shell may include a color
additive so that a uniform and pleasing color is impregnated into
the concrete. This color will last longer than paint on concrete.
Balanced and even hue and intensity of color between separately
cast prefabricated shell components can then be achieved thus a set
of components will be uniform and otherwise match each other in
color and surface treatment.
[0052] The non-reactive reinforcement grid material 20, in one
embodiment of the invention where the thickness of the
prefabricated shell is on the order of four inches thick, is
supported approximately three inches away from the interior surface
of the fiberglass panel 26 by the locators 22. The non-reactive
reinforcement grid will be about one inch inboard from the exterior
surface 12 of the prefabricated shell. Thus, in this embodiment
mentioned above, the wall thickness of the prefabricated shell will
be approximately four inches thick depending on the thickness of
the fiberglass panel. Of course prefabricated shell thickness could
be selected to be in a range of from very thin, perhaps less than
an inch thick, to much thicker than four inches.
[0053] Generally, the exterior surface of the prefabricated shell
will be a smooth surface resulting from the surface of the mold
being smooth. It is possible, and probable in many situations, that
the exterior surface of the prefabricated shell is cast with
architectural relief, stylized relief and contours, or designed to
match existing structures. In this regard, it appears that factory
precast concrete can more easily and conveniently yield cost
effective designs, or at least designs that are more cost effective
than temporary form work. The prefabricated shells can become
quantity production pieces with standard compatible shapes and
sizes for mass production and quick short lead time on order
delivery.
[0054] FIG. 3 is an end view of a column represented by a sketch
showing a portion of an prefabricated shell before the
prefabricated shell is completed by filing it with silica-fume
concrete. In this view the fiberglass panel 26 shows the locators
attached to it, the non-reactive reinforcement grid 20 attached to
the inboard end of the locators 22, and the exterior surface of the
prefabricated shell 12 shown as a dotted line as the prefabricated
shell has not been completed with a filling of silica-fume and
concrete mix. The three radius lines, a, b, c, show the distance
from the center of this tube shaped column. The lines represent the
exterior 12, the non-reactive reinforcement grid 20 and the
fiberglass panel 26 and show how far, relatively, they are from the
center of the column. For instance, the non-reactive reinforcement
grid, or welded wire mesh equivalent, is located closer to the
exterior surface 12, than it is to the internal surface of the
panel 26. For example, the non-reactive reinforcement grid 20 is
supported by the locators 22 to be approximately three inches away
from the panel 26 and about one inch away from what will become the
exterior surface of the prefabricated shell. Precise location of
the non-reactive reinforcement grid is not critical, it is however
suggested that the non-reactive reinforcement grid not be flush
against either the fiberglass or other moisture impervious panel or
the exterior of the prefabricated shell when it is completed.
[0055] FIGS. 4 A-D is a series of sketches that show the acts
followed in making a prefabricated shell of a generally circular
cross-section shape. If this were a pier or column of square
cross-section, or any other closed cross-section, the acts would be
similar if not the same. One act is to prepare the fiberglass panel
26. The panel is formed into a tubular structure as shown and the
surfaces, both inside 30 and outside 32 surfaces, (the "outside
surface" has been referred to as the "interior surface" previously,
and it will be further on, as it is the interior surface of the
completed prefabricated shell) are prepared for the next acts in
the process of making the prefabricated shell. For instance, the
inside surface 30 may be coated with a product, or with protrusions
such as 28, that enhances the strength of the mechanical interface
between the inside surface of the fiberglass panel and the concrete
that will eventually be poured into the prefabricated shell in the
field. The outside surface of the fiberglass panel 26 may also be
prepared with a surface treatment that will enhance, but not bond
tightly together, although a tight bond is an option, the interface
between the fiberglass panel and the silica-fume containing
concrete used in the formation of the prefabricated shell.
[0056] FIG. 4B shows, in a sketch, the location of the non-reactive
reinforcement grid 20 spaced away from the surface 32 by use of the
locators (FIG. 2) which are attached to the surface 32 and to the
non-reactive reinforcement grid 20, in this case, several inches
away from the surface 32.
[0057] Another act in making the prefabricated shell is shown in
FIG. 4C wherein a mold 34, half of a multipart mold shown in this
figure, is positioned or assembled around the structure shown in
FIG. 4B. The mold 34 can be assembled around the fiberglass panel
and the non-reactive reinforcement grid or the fiberglass panel and
non-reactive reinforcement grid can be inserted into a multipart
mold, such as multipart mold 34, or alternatively, a unitary mold,
not shown. The function of the mold 34 is to contain the
silica-fume concrete mixture from flowing away from the fiberglass
and non-reactive reinforcement grid assembly until the concrete
mixture has at least set up, or more typically, has cured in a
controlled manner.
[0058] Note that in the acts of forming the prefabricated shells
here, there is no need to use the conventional "mold and plug"
method of shell formation, as no "plug" is required in this method
of manufacture.
[0059] As shown in FIG. 4D the act of filling or "pouring," the
prefabricated shell with a silica-fume concrete mixture 36 is
complete. The concrete 36 has been poured into the mold 34 and
fills the area between the mold surface. In a preferred embodiment,
the surface on the final prefabricated shell exterior surface 14 in
FIG. 1, will be a smooth surface due to contact with the smooth
finish interior of the mold. Alternatively, the interior of the
mold can be finished in a surface having a non-smooth surface and
even a surface with design character, such as brick shapes in
relief, formed thereon.
[0060] After the prefabricated shell concrete has cured, or before
thorough curing, the mold will be removed from the now completed
prefabricated shell. In one embodiment the exterior surface 12 will
be spaced about an inch away from the now concrete encapsulated
non-reactive reinforcement grid 20 located by the locators 22.
There will be several inches of concrete, preferably a four
thousand pound or higher class X concrete, between the non-reactive
reinforcement grid 20 and the interior of the fiberglass panel 26.
The panel 26 becomes a part of the prefabricated shell and is not
removed but becomes a barrier between the shell and the concrete
core.
[0061] To summarize, the manufacturing acts in the prefabrication
of the shell include the acts of: preparing an inner wall
structure, this being a fiberglass or plastic panel; positioning a
carbon fiber grid at a spaced distance around the inner wall
structure using locators or spacers as positioning elements; either
placing the inner wall structure with the fiber grid in a mold or
else building a mold around the inner wall structure and fiber
grid; filling the space between the mold surface, which can be a
metal, wood, natural or synthetic surface appropriate for imparting
a desired finish to what will become the outside surface of the
prefabricated shell, and the interior surface of the inner wall
structure; curing the augmented concrete in the mold and then
removing the prefabricated shell from the mold once it is cured.
One additional act may also be performed in the shell fabrication
process. That act is the setting of lifting pin receivers and
lifting pins, as appropriate, in the mold cavity before the cavity
is filled with the silica-fume concrete mixture. These lifting pins
will be used for lifting the prefabricated shell at various
handling stages before the shell is finally field filled with
concrete. Furthermore, non-corrosive inserts can be cast into the
shells to accept a heavy duty bolt, or bolts, for lifting, shoring,
bracing, or material handling purposes.
[0062] FIGS. 5 A-D are very similar to the FIG. 4 series of figures
but show a rectangular open top box-like structure that will
normally be used as a spanning, bridging, bent cap, or truss-like
support at the construction site. The FIG. 5 embodiment is one
embodiment of the invention, however, many other shapes of open top
prefabricated shells, that is prefabricated shells that are
box-like structures that are rectangular, square, multisided,
round, oval, or the like, that are intended to be filled through
the open top with concrete at the job site once the prefabricated
shell is positioned or staged for installation, are contemplated by
the inventor. One act in the series of acts shown in FIG. 5 is to
prepare the fiberglass panel 26. This panel, similar in composition
to the previously mentioned fiberglass panels, is formed into a
box-like structure as shown in FIG. 5A and the surfaces, both
inside 30 and outside 32 surfaces, (the "outside surface" has been
referred to as the "interior surface" previously, and it will be
further on as well, as it is the interior surface of the completed
prefabricated shell) are prepared for the next acts in the process
of making the prefabricated shell. The surfaces of the fiberglass
panels are treated as above.
[0063] FIG. 5B shows, as a sketch, the location of the non-reactive
reinforcement grid 20 spaced away from the surface 32 by use of the
locators (FIG. 2) which are attached to the surface 32 and to the
non-reactive reinforcement grid 20, in this case, several inches
away from the surface 32.
[0064] A further act in making the prefabricated shell for the open
top structure is shown in FIG. 5C wherein a mold 34, a portion of a
multipart mold shown in FIG. 5C, is positioned or assembled around
the structure shown in FIG. 5B. The mold 34 can be assembled around
the fiberglass panel 26 and the non-reactive reinforcement grid or
the fiberglass panel and non-reactive reinforcement grid can be
inserted into a multipart mold, such as multipart mold 34 shown in
FIG. 5C, or alternatively, a unitary mold, not shown.
[0065] As shown in FIG. 5D the act of filling the void between the
prefabricated shell with a silica-fume concrete mixture 36 is
complete. The concrete 36 has been poured into the mold 34 and
fills the area between the mold surfaces. In a preferred
embodiment, the surface on the final prefabricated shell exterior
surface 14 in FIG. 1, will be a smooth surface due to contact with
the smooth finish interior of the mold 34. Alternatively, the
interior of the mold 34 can be finished in a surface having a
non-smooth surface and even a surface with design elements, such as
contour shapes in relief, formed thereon.
[0066] As stated above with respect the pier or column
prefabricated shell shown in FIG. 4, after the concrete poured into
prefabricated shell has cured, or before thorough curing, the mold
34 will be removed from the now completed open top box-like
prefabricated shell. The panel 26 becomes a part of the
prefabricated shell and is not removed under normal circumstances.
It becomes the innermost surface of the prefabricated shell and is
the surface that will be in contact with the concrete that is
poured into the shell at the construction site.
[0067] FIG. 6 shows a cross sectional view of a pier column
generally 38 illustrative of a prefabricated shell structure that
has been field-filled with concrete. The prefabricated shell
comprises the fiberglass panel 26, the locators 22, the
non-reactive reinforcement grid 20, and the silica-fume containing
concrete structure 36, all of which make up the form. In this FIG.
6 depiction the prefabricated shell is filled with concrete 40
showing a completed column, as it would be completed at a
construction site. This embodiment includes an optional structure
support lip 42 in the vicinity of the top of the pier or column as
well as an optional depth limiting lip 44 near the bottom of the
column. Since the prefabricated shell comprises silica-fume
augmented cement the structure support lip 42 and the depth
limiting lip 44 will have properties similar to the strength
properties of the main section of the prefabricated shell.
[0068] Also shown in FIG. 6 is a base element 46 including relief
or pocket 50 that will accept the base of the pier column 38.
Similarly, a truss structure 52 has a relief or pocket 54 that will
accept the upper end of the column 38. The column 38 will support
the truss structure 52 primarily through the bent cap or truss
structure 52 bearing on the top of the column rather then having
the structure support lip 42 supporting the weight of the truss
structure 52. The bottom of the column 38 will rest on the floor of
the cavity 50 so that the weight of the column 38 and any load it
is supporting is taken by the base of the column 38 and the base
element 46 rather than the depth limiting lips 44.
[0069] One embodiment of a prefabricated shell for the construction
of a base element 46 is shown in FIGS. 7-9. In FIG. 7 a
prefabricated shell for a base element is shown having walls such
as 54 integral with a top 56. The top 56 has through apertures that
will, after the prefabricated shell is filled with concrete, form
the pockets 50 shown in FIG. 6.
[0070] The interior of the prefabricated shell 46 comprises the
fiberglass panel 26 as discussed above in the description of the
column shells. The fiberglass panel is shown as a dotted line in
FIG. 8 and is clearly shown in FIGS. 7 and 9. The structure of the
prefabricated shell includes the fiberglass panel 54, the locators
22 and the non-reactive reinforcement grid 20 as pictorially
depicted in FIG. 9. Not shown in any of these three views is the
external, removable mold, similar to the mold 34 shown in FIGS. 5C
and 5D. The mold for this base unit will be slightly more
complicated than the mold shown in FIGS. 5C and 5D as there are
radiused ends rather than the square ends in FIG. 5. The principle
of filling the void between the fiberglass panel 54 and the mold
with silica-fume concrete is the same as is discussed above. This
also includes the inclusion of the non-reactive reinforcement grid
sheet of material 22 spaced away from the fiberglass plates 26
through the use of the locators 22.
[0071] It should be pointed out that the use of silica-fume
additive is one embodiment contemplated by the inventor. It is, of
course, possible to use other concrete property enhancing
additives, such as but not limited to ground granulated blast
furnace slag, or the like.
[0072] The base element or prefabricated base shell will be shipped
in the form shown in FIG. 7 to a job site where it will be
positioned and then filled with concrete of the design engineer's
specification. With this base unit in place and filled, the next
act, if the base is being used as a support for a column, is to
position prefabricated shell columns in the pockets 50 and then
fill the columns with concrete. Alternatively, the columns can be
placed before any concrete is poured into the base unit. After the
columns are placed in the base unit, and supported thereon by the
depth limiting lips 44 of FIG. 6, concrete can be poured into the
columns and the base unit in a single operation.
[0073] The prefabricated shell FIGS. 7-9 is described above as a
base unit. The same structure can be used as a bent cap or truss
structure such as item 52 of FIG. 6, if it is inverted. The forming
of the truss structure 52 is as described above but the
prefabricated shell is inverted when placed on the columns,
generally being supported by structure support lips 42 of FIG.
6.
[0074] FIG. 10 shows an embodiment of the invention having post
tension strands 60 inserted in the prefabricated shell 16. As seen
in FIG. 11, the end of the prefabricated shell 16 is provided with
sleeves, such as 64, through the face or side of the prefabricated
shell. Locking assemblies such as 62 are placed to interface with
the post tension strands 60. The locking assemblies and the sleeves
do not compromise the integrity of the shell and it remains
watertight and highly resistant to fluid contamination, such as
chloride slurry resulting from melting ice, melted from chloride
applications, on roadways.
[0075] FIGS. 12 and 13 illustrate a vertical joint between two
stacked prefabricated shells, a lower shell 66 and an upper shell
68. A watertight connection is made between the two stacked shells
by use of bituminous mastic joint compound 70, which is positioned
on an upper ledge 72 at an upper location on the lower shell. A
spacer, here a stack of adjustment shims 74, are stacked on a low
ledge 76 of the upper location of the lower shell 66. A lip or
flange 80 will come into play when the upper stacked shell 68 is
lowered onto the lower stacked shell 66. This is shown in FIG. 13
wherein the upper shell is positioned in its final position on the
lower shell. The pressure exerted between the upper and the lower
shells during assembly compress the bituminous mastic causing it to
form a water tight seal between the upper and lower shells. It is
kept from flowing into the interior of the shells by the lip or
flange 80 as can be seen in FIGS. 12 and 13. The final position is
accomplished when the shells are filled with concrete and the shim
stack 74 is removed. An expending void foam filler material 82 is
injected into the joint between the lower and the upper shells. A
foam backer rod 88 separates the filler material 82 from caulk
material. The remaining crevice is filled with a caulk compound 84
such as "Sika-Flex" brand caulk. The expanding foam will assist in
preventing water, vapor, or chloride-ion migration through the
joint void to the interior concrete. The Sika-Flex, or other
caulking system, assists in bonding the shells to the expanded foam
filler. At this point, that is, after the shells are filled with
concrete, the concrete core becomes the supporting structure of the
finished pier or column.
[0076] FIGS. 12 and 13 show the placement of a representative
plastic insert 102 that may be cast into the shell. The insert 102
is provided to accept a bolt, such as 104, or other similar
lifting, shoring, bracing, or supporting fixture that is inserted
into the insert 102 for the use of lifting, shoring, bracing, or
support. For instance, in FIG. 13, a support link 106 can be bolted
to the shell by the bolt 104 passing through an aperture in the
support link 106 into the threaded, non-corrosive insert. The
non-corrosive insert will prevent the bolt from providing a
moisture path to the inside of the shell. When the bolt is removed,
for instance, if it is a temporary placement for supporting or
aligning the shell, the insert 102 may be filled with caulk,
covered with an end cap or both. In some instances, it may be
unnecessary to fill the plastic insert as there may be no concern
about moisture entering the shell through the insert 102.
Generally, the insert 102 will not penetrate deeply into the shell
and thus there is reduced chance that contamination can traverse
the shell and get into the shell or the concrete that is poured
into and fills the shell.
[0077] Another use for the insert 102 is to accept a more permanent
shoring rod, not shown, that would extend from in the insert to a
locator that accepts the other end of the locator. The locator
could be, for instance, secured to the ground, secured to a nearby
structure, or to another part of the same structure to provide
bracing, strength, and location maintenance capability.
[0078] It should be noted that all the sealers, caulks and fillers
used in the invention and the application of the invention are
non-rigid and compressible. They will however keep each piece of
prefabricated shell from resting on an adjacent shell as seen in
FIGS. 12 and 13. Since corrosion resistance is important; the
sealers, fillers, caulks, and the like are non-corrosive.
[0079] FIG. 14 is a cross sectional view of a monolithically poured
concrete structure, generally 86, that is shown poured into a
prefabricated shell 90. This structure is a shell that is
fabricated as set forth above. The column portions 92 extend
upwardly from the base portion 94 to the beam portion 96. In a
preferred embodiment this shell will be cast as a single piece but
may, alternatively be made of several pieces, such as a base piece,
the column pieces and the beam piece, each separate but assembled
in the field before the now unified shell structure is filled with
concrete. It may be desirable to insert metal reinforcement bars
into the shell before the shell is filled with concrete. Of course
the shell will have the fiberglass or HDPE sheet or panels that
will help protect the prefabricated shell from contact with the
rebar. The reinforcing bar will end up in the poured concrete and
will be sealed from the elements as set forth above. The shell
generally 86 may be opened on the bottom of the base portion as
shown or a bottom may be cast into the form as a bottom of the base
(not shown). Generally, the top of the beam portion is covered with
a lid structure (see FIGS. 15 and 16). The advantage of the form
structure shown in FIG. 14 is that a single pour can be made to
fill the prefabricated shell at the job site. The prefabricated
shell 90, (reference character 90 used to show two surfaces of the
same shell), will have an exterior surface as shown such as in FIG.
2 as outer layer 12, the sheet of carbon fiber material 20, the
spacers or locators 22 and the fiberglass panel 26. Not readily
seen in FIG. 14 are the protrusions 28.
[0080] FIG. 15 is a cross sectional view of a lid or cap 110 shown
expanded away from an open pour element such as 112. Both of these
components are prefabricated elements that include the same mix,
the enhanced concrete using silica-fume or slag and 4,000 pound
concrete, and structural elements as other preformed shells
described above (like reference numbers indicate like elements). In
the field the cavity of the open pour section 1 12 will be filled,
or almost completely filled, with concrete and the lid 110 placed
over the cavity of the now filled open pour cavity. Composite dowel
rods, such as those shown as 114, will be cast into the lid as
shown in FIG. 15. After the pour of concrete into the open pour
section 112 the lid will be lowered onto the open element and the
dowel rods inserted in the newly filled concrete pour of the
section such as 112. In the event that more concrete needs to be
added to fill the cavity under the lid, pour openings such as items
124 in FIG. 15 and FIG. 16 may be provided. The pour openings will
be used as fill access ports, or, if too much concrete is poured
into the cavity and needs to be extruded out of the structure, the
pour openings may act as spill ports to allow concrete to flow out
of the lidded cavity. In some situations some of the openings will
be needed to add concrete while other of the ports or openings 124
will be used to let concrete escape. The pour openings 124 may be
sealed after the appropriate concrete fill quantity has been poured
into the structure.
[0081] A drip edge 114 extends from the edge of the lid to direct
water away from the joint between the lid and the open pour section
112. A mastic joint sealer 114 is placed between the lid and the
upper edge of the open pour section such that when the lid is
placed on the section 112 a seal will be formed through compression
of the mastic or compound sealer.
[0082] FIG. 16 shows an alternative joint between the lid 118 and
the cavity wall 120. In this embodiment a stepped joint 122 is
used, either as an alternative to the mastic joint discussed above,
or in addition to the mastic joint. That is the step joint may also
use mastic to further the efficacy of the seal between the lid 118
and the wall of the open pour section 120.
[0083] A summary of the invention is that it is a prefabricated
concrete shell that forms a component of a concrete structural
element. The prefabricated shell comprises concrete; an additive
mixed into the concrete before the concrete is cured; a panel of
fluid impervious material forming a surface of the prefabricated
shell; a locator extending from the panel of fluid impervious
material; and a sheet of mesh fabric spaced apart from the panel.
This sheet is located in position by a locator. In one embodiment
the additive comprises a reactive pozzolan. This may be what is
known as silica fume. In another embodiment the additive can be
amorphous silicon dioxide. One advantage of the invention is that
the shell, made of concrete with one of the above additives is
highly resistant to chloride ion migration and corrosion induced by
deicing or marine salts. The mesh fabric used in the shell is a
carbon fiber mesh grid while the fluid impervious material
comprises a substantially non-metallic membrane. Substantially
non-metallic may include having no metallic component at all to the
membrane however it is possible that some metallic component can be
used as long as there are oxidation minimizing attributes to a
membrane having even some metallic content. Similarly the mesh
fabric, preferably oxidation resistant, which, in one embodiment is
nonmetallic may, in another embodiment, be substantially
non-metallic. The mesh fabric will be non-deleterious to the
strength of the concrete. The mesh fabric can be fiber mesh, such
as but not limited to, a carbon fiber mesh. The prefabricated shell
may have a smooth exterior for aesthetic and other reasons. The
smooth exterior is formed using a smooth metal form finish to the
concrete on the exterior of the prefabricated shell.
[0084] The panel of fluid impervious material may be mineral fibers
such as fiberglass. It is expected that the panel of fluid
impervious material is a water impervious material, which in one
embodiment is a 16-ounce/square foot fiberglass panel. The panel of
fluid impervious material further comprises a resin coating, such
as a polyester based coating. The locators in the structure are
preferably nonmetallic but may, in another embodiment be
substantially nonmetallic. These locators are positioned between
the sheet of mesh fabric and the panel of fluid impervious
material. The locators may be attached to the sheet of mesh fabric
and to the panel of fluid impervious material as well.
[0085] The fabrication of a shell, in one embodiment, is
accomplished by performing acts comprising: providing a mold, the
mold being a surface wherein the prefabricated shell is molded;
providing a panel of fluid impervious material comprising an
interior surface; positioning locators proximate the panel of fluid
impervious material of the form; providing a sheet of mesh fabric
and locating the sheet of mesh fabric proximate the panel of fluid
impervious material of the form; placing the panel of fluid
impervious material, locators and sheet of mesh fabric in the mold;
pouring concrete into the mold, whereby the sheet of mesh fabric
and the locators are surrounded by concrete and the concrete
contacts the interior surface of the panel of fluid impervious
material.
[0086] Furthermore the process includes curing the concrete in the
mold to form a prefabricated shell. The locators are attached to
the fluid impervious material and to the sheet of mesh fabric.
[0087] The structure that is formed comprises a prefabricated
concrete shell forming a component of a concrete structural
element. This prefabricated shell comprises concrete including an
additive mixed into the concrete before the concrete is cured; a
panel of fluid impervious material forming a surface of the
prefabricated shell; a locator extending from the panel of fluid
impervious material; a sheet of mesh fabric spaced apart from the
panel, the sheet located in position by the locators; a core of
concrete located inside the prefabricated concrete shell, the core
of concrete adjacent the panel of fluid impervious material, the
core of concrete having an additive mixed into the procured
concrete, the additive in the concrete being of a lesser amount by
percentage than the additive used in the concrete of the
prefabricated concrete shell. The additive is silica-fume, a
reactive pozzolan, in one embodiment. The additive may be an
amorphous silicon dioxide in another embodiment.
[0088] Each variation of the invention is limited only by the
recited limitations of its respective claim, and equivalents
thereof, without limitation by other terms not present in the
claim. Likewise, the use of the words "function" or "means" in the
Detailed Description of the Drawings is not intended to indicate a
desire to invoke the special provisions of 35 U.S.C. 112, Paragraph
6, to define the invention. To the contrary, if the provisions of
35 U.S.C. 112, Paragraph 6 are sought to be invoked to define the
inventions, the claims will specifically state the phrases "means
for" or "step for" and a function, without also reciting in such
phrases any structure, material or act in support of the function.
Even when the claims recite a "means for" or "step for" performing
a function, if they also recite any structure, material or acts in
support of that means or step, then the intention is not to invoke
the provisions of 35 U.S.C. 112, Paragraph 6. Moreover, even if the
provisions of 35 U.S.C. 112, Paragraph 6 are invoked to define the
inventions, it is intended that the inventions not be limited only
to the specific structure, material or acts that are described in
the preferred embodiments, but in addition, include any and all
structures, materials or acts that perform the claimed function,
along with any and all known or later-developed equivalent
structures, material or acts for performing the claimed
function.
* * * * *