U.S. patent application number 17/308912 was filed with the patent office on 2021-08-19 for decorative concrete with uniform surface and method of forming the same.
The applicant listed for this patent is Shaw & Sons, Inc.. Invention is credited to Ronald D. Shaw.
Application Number | 20210254335 17/308912 |
Document ID | / |
Family ID | 1000005567764 |
Filed Date | 2021-08-19 |
United States Patent
Application |
20210254335 |
Kind Code |
A1 |
Shaw; Ronald D. |
August 19, 2021 |
DECORATIVE CONCRETE WITH UNIFORM SURFACE AND METHOD OF FORMING THE
SAME
Abstract
A decorative concrete with a very uniform finish surface and a
method of fabricating the same is disclosed. A concrete mixture is
poured over a subgrade which defines an exposed surface. The
exposed surface is finished with any of several techniques, and the
surface is then worked with an abrasive material, and additional
techniques are used to color and seal the concrete.
Inventors: |
Shaw; Ronald D.; (Costa
Mesa, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shaw & Sons, Inc. |
Costa Mesa |
CA |
US |
|
|
Family ID: |
1000005567764 |
Appl. No.: |
17/308912 |
Filed: |
May 5, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15922481 |
Mar 15, 2018 |
11028582 |
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17308912 |
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15097634 |
Apr 13, 2016 |
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15922481 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B28B 23/02 20130101;
C04B 41/009 20130101; B28B 1/14 20130101; E04C 2/044 20130101; B28B
11/0872 20130101; C04B 41/53 20130101; E04F 21/245 20130101; E04F
21/24 20130101; B28B 11/08 20130101; B28B 11/044 20130101; E04C
2/06 20130101; E04F 21/247 20130101; B24B 7/22 20130101; B28B
19/0007 20130101; E04F 21/248 20130101; B29L 2031/10 20130101; E04C
2002/005 20130101; C04B 28/02 20130101; B28B 11/0845 20130101; B28B
11/0818 20130101; B28B 11/04 20130101; C04B 41/533 20130101; C04B
41/72 20130101; C04B 41/5323 20130101 |
International
Class: |
E04C 2/06 20060101
E04C002/06; E04F 21/24 20060101 E04F021/24; B24B 7/22 20060101
B24B007/22; C04B 41/53 20060101 C04B041/53; C04B 28/02 20060101
C04B028/02; C04B 41/72 20060101 C04B041/72; E04C 2/04 20060101
E04C002/04; C04B 41/00 20060101 C04B041/00; B28B 11/04 20060101
B28B011/04; B28B 11/08 20060101 B28B011/08; B28B 23/02 20060101
B28B023/02; B28B 1/14 20060101 B28B001/14; B28B 19/00 20060101
B28B019/00 |
Claims
1-15. (canceled)
16. A method of forming a decorative concrete slab having a highly
uniform exposed surface, comprising: pouring a concrete mixture
over a subgrade, the concrete mixture defining an exposed top
surface when poured; finishing the exposed top surface; allowing
the concrete to harden; and applying an abrasive upon the exposed
top surface to reduce any nonuniformity of the exposed top
surface.
17. The method of claim 16, further comprising the steps of washing
the surface film, curing the slab with water, and power washing the
slab.
18. The method of claim 16, further comprising sand blasting the
exposed top surface after allowing the concrete to harden.
19. The method of claim 16, further comprising acid washing the
exposed top surface after allowing the concrete to harden.
20. The method of claim 16, wherein finishing the exposed surface
comprises applying aggregate.
21. The method of claim 16, wherein the abrasive is sandpaper.
22. The method of claim 16, wherein applying the abrasive is done
with a machine.
23. The method of claim 16, wherein finishing the exposed surface
comprises applying fine sand.
24. The method of claim 16, wherein finishing the exposed surface
comprises applying a mixture of fine sand and aggregate.
25. The method of claim 16 further comprising the step of applying
a stain after applying the abrasive to the exposed top surface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND
Field of the Invention
[0003] The present invention relates in general to concrete
products, and more particularly, to a method of creating decorative
concrete with a highly uniform surface and the method of forming
the same.
Description of the Related Art
[0004] As is well known in the building and construction trade,
concrete is extensively utilized as a building material for
commercial and residential applications. In this regard, due to its
durability, water resistance, and cost economy, concrete has gained
widespread use. With this widespread use, there is a demand for
decorative concrete that possesses improved aesthetics such as a
highly uniform surface.
[0005] Although numerous methods of concrete finishing have been
developed in prior art, such as salt finish, broom finish, and form
pressed finish (i.e. stamp concrete), the use of such conventional
techniques have typically failed to provide the desired result,
i.e. aesthetics, of the resultant concrete surface to be highly
uniform. In this regard, although techniques have been developed to
provide a more uniform concrete, such attempts have been generally
difficult or costly to install. Further, such prior art methods
have typically focused on working the concrete before hardening by
surface treating the concrete with additional material while the
concrete is still in a plastic state.
[0006] As such, there exists a need in the art for decorative
concrete with a highly uniform finish, as well as an economical
method of forming the same. Various aspects of the present
invention are specifically directed toward addressing these
particular needs as will be discussed in more detail below.
BRIEF SUMMARY
[0007] The present invention is best understood by reference to the
following detailed description when read in conjunction with the
accompanying drawings.
[0008] Disclosed is a method of forming a decorative concrete
surface having a highly uniform exposed surface, preferably
including preparing a subgrade, pouring a concrete mixture over the
subgrade, the concrete mixture defining the exposed surface when
poured, applying a finish technique to the exposed surface, working
the exposed surface with an abrasive compound and applying a
surface retarder to the exposed surface.
[0009] The method further may include the steps of washing the
surface film, curing the concrete with water, and power washing the
top surface. The method can further include sand blasting; acid
washing; and/or applying aggregate to the top surface of the
concrete.
[0010] After the concrete has hardened, the method utilizes an
abrasive, such as a low grit sandpaper, which is applied to the top
surface of the concrete. Preferably the sandpaper comprises a
twenty grit sanding disc which may be mechanically or manually run
over the top surface of the concrete. Although intuitively the
application of a low grit sandpaper on the top surface of the
concrete would seem to make the top surface of the concrete uneven
and/or rough, the applicant has found that it actually evens out
the sand particles creating a more uniform finish on the top
surface of the concrete.
[0011] Following the abrasive sanding application, the top surface
of the concrete may optionally be provided with conventional
surface treatment, such as concrete stain and/or concrete sealers
as desired. The method of the present invention can be utilized for
both new concrete installations and is suitable for use on nearly
all concrete finishing techniques, such as brooming finish, hand
trowel finish, sand blast finish, stamp concrete finish, or acid
wash finishes. Further, the present invention is additionally
suitable for use on existing concrete installations as a retrofit
application to improve the uniformity and aesthetics of the top
surface of existing concrete installations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These and other features and advantages of the various
embodiments disclosed herein will be better understood with respect
to the following description and drawings, in which like numbers
refer to like parts throughout, and in which:
[0013] FIG. 1 illustrates a perspective cross sectional view of the
decorative concrete structure of the present disclosure;
[0014] FIG. 2 illustrates the method of forming the decorative
concrete; and
[0015] FIG. 3 illustrates the step of working the concrete with an
abrasive material.
DETAILED DESCRIPTION
[0016] Referring first to FIGS. 1 and 2, the decorative concrete
structure 10 of the present invention providing a highly uniform
surface and the method for preparing a decorative concrete
structure 10 is shown. Various aspects of preparing the decorative
concrete structure 10 result in a decorative concrete structure 10
which provides a highly uniform surface of the concrete.
[0017] An initial step in forming the decorative concrete structure
10 may optionally comprise preparing a subgrade 8. The subgrade 8
may provide uniform support for the decorative concrete structure
10. Typically, the initial step involves excavating the ground to a
desired elevation and compacting the ground preferably to 90%
compaction to ensure a uniform and stable support. After compacting
the subgrade 8, the subgrade may be covered with a layer of clean,
moist, fill sand 12 which preferably defines a minimum thickness of
approximately four inches. Although the fill sand 12 is not
necessary for the method of producing the decorative concrete
structure 10, it is desirable to control the hydration process of
the decorative concrete structure 10.
[0018] After preparing the subgrade 8, should such a preparation be
required or optionally chosen, conventional forms or form members
may be placed around the perimeter of the designated pour area 15
to create a cavity within which the concrete mixture 16 is poured.
As is well known, the form members create a solid barrier that
maintains the concrete mixture 16 in place and forces the concrete
mixture 16 to assume a desired external boundary configuration. The
form members may be fabricated from plywood, plastic, aluminum,
steel, or other materials known in the art.
[0019] Optionally, and depending on the requirements of the work
site or the use of the concrete at the site, after preparing the
forms for the decorative concrete structure 10, reinforcing members
14 such as rebar or a wire mesh may be used to increase the
resultant strength of the decorative concrete structure 10. The
reinforcing members 14 provide increased strength and/or mitigate
the likelihood of cracking within the decorative concrete structure
10. The reinforcement members 14 may be positioned upon
conventional concrete chairs disposed over the layer of fill sand
12 to define a lattice framework, or other arrangements known by
those skilled in the art.
[0020] After the reinforcing members 14 are placed, should the
reinforcing members be required or optionally chosen, a
conventional concrete mixture 16 is poured within the forms. The
concrete mixture 16 is preferably poured to define a depth of
approximately 3.5-4.0 inches, however, other depths are also
contemplated. Although variations in the concrete mixture 16 are
contemplated, the preferred concrete mixture 16 comprises 70% sand
and 30% aggregate combined with portland cement preferably (2,000
pounds per square inch) or (3,000 pounds per square inch). Further,
depending on desired aesthetics of the exposed surface 18, an
integral color additive may be added to the concrete mixture 16 to
achieve the desired state.
[0021] After the concrete mixture 16 has been poured, the top
surface of the concrete mixture 16 is screeded to produce a flat
surface that defines the exposed top surface 18. The top surface 18
of the concrete mixture 16 is screeded to remove excess concrete
and to bring the top surface of the concrete mixture 16 to a
desired plane or grade determined by the form members.
[0022] After screeding the concrete mixture 16 to the desired plane
or grade, the exposed surface 18 may be surface finished with a
conventional finishing tool to dispose a quantity of the
cement/fine paste derived from the concrete mixture 16 at the
exposed surface 18 thereof. For example, a float tool such as a
bull float 17 or vibrating bull float may be used to create a
smooth and flat upper surface and to remove surface imperfections.
In addition to bringing up the appropriate amount of cement/fine
paste, the float may seal the exposed surface 18 of the concrete
mixture 16. An exemplary metal bull float is sold under the
trademark HAL200 by the Lievers Holland Co. although other floats
are contemplated herein.
[0023] After finishing with the float tool 17, a conventional
trowel tool may be applied to the exposed surface 18. The troweling
may be accomplished by a mechanical trowel machine or manually by a
hand trowel.
[0024] In an optional step, while the exposed surface 18 of the
concrete mixture 16 is still in a plastic state, fine sand or
aggregate, or a combination thereof 22 may be broadcast over the
exposed surface. The fine sand, aggregate, or combination thereof
22, may be of any given color or texture, as required to produce
the desired finish appearance 24. Further, it is contemplated that
various combinations of color, texture, or other characteristics of
the fine sand may be variously created in order to accurately
simulate, for example, quarried stone. Examples of such methods are
known in the art and are disclosed, for example, in U.S. Pat. Nos.
8,079,775 7,781,019, 7,614,820, and 5,794,401 to Shaw et al., the
contents of which are expressly incorporated herein by
reference.
[0025] It is further contemplated that the exposed surface may be
worked first with a conventional brooming tool 24 to create
patterns in the exposed surface that resemble wood grain.
[0026] According to an implementation of the present invention, it
is contemplated that the broadcasting of the fine sand and the
aggregate may be performed utilizing pneumatic equipment. The
pneumatic equipment may allow the operator to produce a randomized
pattern or a design corresponding to a particular natural material.
Thus, the appearance of the exposed surface may be enhanced
utilizing other tools such as pneumatic equipment.
[0027] After being broadcast upon the exposed surface of the
concrete mixture, the fine sand and the aggregate are mixed or
worked 23 into the exposed surface 18 of the concrete mixture 16,
and more particularly are mixed into the cement/fine paste of the
exposed surface. This may be accomplished utilizing a power trowel.
However, it is contemplated that the mixing may be accomplished
utilizing other devices known in the art.
[0028] Once the exposed top surface has been finished with any of
the foregoing methods, the concrete mixture is allowed to harden 25
which typically occurs within twenty-four to forty-eight hours
after the concrete is poured.
[0029] In an optional step, after the concrete has hardened, the
exposed surface may be acid washed or sandblasted 35 to expose the
aggregates within the concrete. Essentially, the sand blasting
erodes the surface layer of the concrete, but sand blasting can do
more depending on the chosen grade of sand blasting.
[0030] After hardening of the concrete mixture 16, and optional
application of one or none of the above finish techniques, the
exposed top surface 18 is treated by applying an abrasive or
abrasive member in a side-to-side sweeping reciprocal or in a
rotary motion. The side-to-side sweeping reciprocal motion is
indicated by the arrows on either side of the machine 100 in FIG.
3. The abrasive may be sandpaper, emery cloths or honing stones, or
similar abrasive discs or pads 40 to achieve the desired uniform
finish appearance 24. The abrasive may have any one of varying
degrees of abrasiveness in order to treat the exposed surface and
achieve the desired finish appearance 24. For example, depending on
the techniques used on the concrete used prior to and during
hardening, a more or less abrasive material may be required to
achieve the desired finish appearance 24. A range of abrasiveness
exemplified by 10 grit to _4000 grit sandpaper is contemplated. For
most applications, 20 grit sandpaper is used, but other grades of
sandpaper as well as other abrasives are contemplated depending
upon the surface finish applied in the previous step and the
desired end finish.
[0031] As shown in FIG. 3, the sandpaper may be worked across the
exposed surface either by hand or machine 100. Conventional
machines that may be used in working the exposed surface may
include a rotary polisher, or rotary sander, a belt sander or a
reciprocating sander. Any of the abrasives may alternatively be
worked by hand, including the use of hand tools, for example, a
sanding block, or handheld power tools, such as a handheld
reciprocating sander or handheld belt sander.
[0032] Typically, the machines will be used with sandpaper
manufactured for attachment to the machine. The sandpaper may be in
either in disk, belt or sheet formats, as required by the
configuration of the machine. The abrasive particles embedded in
the sandpaper act to either remove or fracture small sand particles
in the exposed surface 18, which creates the more uniform final
finish for the exposed surface, giving it the desired finish
appearance 24. However, either purpose manufactured disks, belts,
or sheets of alternate materials, or custom manufactured
combinations of materials and formats may be used as well. For
example, a user may manufacture a belt emery cloth for use in a
belt sander.
[0033] Further, a process of working the exposed surface with
progressive abrasives is contemplated. Again, depending on the
techniques used while the concrete is still plastic, more or fewer
steps may be required. For example, in a first step, the exposed
surface may be worked with 10 grit sandpaper, in a next step, the
exposed surface is worked with a finer grit sandpaper, for example,
80 grit. In a final step, the exposed surface is worked with an
even finer grit sandpaper, for example, 100 grit. In using this
method, the particles removed or fractured in each step become
increasingly smaller, and the exposed surface takes on a more and
more uniform appearance. Depending on the starting point of the
exposed surface due to the various techniques used while the
concrete was still plastic, only one or two steps, instead of
three, may be required.
[0034] The preferred embodiment for large, essentially flat areas
of exposed surface uses a rotary polisher or rotary sander and a
disk 102 of sandpaper, but, as noted above, other machines and
shapes of abrasive may be used, including belt and reciprocating
sanders, with belts, squares or rectangles of sandpaper or other
abrasives. The use of the rotary polisher or rotary sander,
especially where the sandpaper is applied either in a generally
rotary or side-to-side sweeping reciprocal motion, lends to the
easiest achievement of a uniform surface.
[0035] Some circumstances may render the use of a rotary machine
either impossible or impractical. In such circumstances, the
desired highly uniform appearance may be best achieved by the use
of alternative machines or working the surface by hand. For
example, conventional belt or reciprocal sanders may be used on the
treads of a concrete stairway. In such circumstances, the best
motion to work the exposed surface may be a one-way or
back-and-forth linear reciprocating motion. The vertical surfaces
of the risers of the stairway may be best worked by hand, or by
handheld power tools. Working the exposed surface by hand or with
handheld tools allows for a wide range of techniques, as the
overall motions tend to be smaller, and are more easily controlled.
Thus, any time the exposed surface is worked by hand, as in the
case of the risers, the circular or reciprocating sweeping motions
of the rotary polisher or rotary sander, or the more linear
techniques discussed in conjunction with the belt or reciprocating
sander may be used.
[0036] In an alternative method, large flat areas may be worked by
machine, and then areas determined by the user to require
additional working may be done by either machine or hand. For
example, it is known by one of ordinary skill in the art that when
using a rotary polisher or rotary sander, linear boarders, such as
edges where the concrete ends, and landscaping begins, or where the
exposed surface abuts a structure, are difficult to work uniformly.
After using one machine, such as a rotary polisher or rotary sander
in such an area, anther machine, for example, a belt sander may be
used to work any exposed surface requiring additional working to
achieve a highly uniform finish. Alternatively, such areas may be
worked by hand to ensure that crossover, and the corresponding
possibility of overworking certain areas relative to immediately
adjacent areas, is minimized.
[0037] As another alternative, different techniques may be applied
in adjacent areas to create a pattern. For example, where there may
be conventional saw cuts made in the surface of the concrete in
order to control cracking. One area defined within certain saw cut
borders may be treated to a finish appearance using a chosen grade
of abrasive, while an adjacent area, defined by at least one common
saw cut, is finished to a different finish appearance using a
rougher or finer grade of abrasive.
[0038] Again with reference to FIGS. 1 and 2, following sanding the
exposed surface 18, an optional concrete stain 45 or sealer or
protective coat 50 may be applied to achieve a final desired
appearance 24 and texture.
[0039] As illustrated in FIG. 2, the concrete mixture may be cured
utilizing water alone 70, as opposed to chemical curing agents in
order to avoid staining of the exposed surface. Such water curing
may typically be facilitated through the use of a conventional
fogger or soaker hose. After a prescribed period of time (e.g., 30
days after initiating the curing process) any surface residue
present on the exposed surface is removed by conventional power
washing 75 with a ninety percent (90%) steam and ten percent (10%)
muriatic acid mixture which is applied by a power washer via a high
pressure nozzle.
[0040] The above description is given by way of example, and not
limitation. Given the above disclosure, one skilled in the art
could devise variations that are within the scope and spirit of the
invention disclosed herein, including various ways of cutting into
the exposed surface 12 to create a pattern that resembles planks
found in conventional natural wood decks. Further, the various
features of the embodiments disclosed herein can be used alone, or
in varying combinations with each other and are not intended to be
limited to the specific combination described herein. Thus, the
scope of the claims is not to be limited by the illustrated
embodiments.
* * * * *