Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02695333 2010-03-04
TITLE OF THE INVENTION
AGGREGATE REPAIR METHOD AND PRODUCT
FIELD OF THE INVENTION
The present invention relates to a method for repairing cracks in exposed
aggregate
concrete surfaces, such as residential driveways, and a product for use in
same.
BACKGROUND OF THE INVENTION
Exposed aggregate is a common building material. One common example of its use
is
as a driveway surface. While visually appealing and relatively strong and
maintenance
free, exposed aggregate can become cracked. These cracks both disturb the
visual
appeal of the exposed aggregate and are cause for concern for further water
damage.
Water that runs into the crack, say from rain, melting snow, or a garden hose,
can
result in the erosion of interior crack surfaces, as well as undermining the
support of
the concrete substrate. When frozen, any water within the crack causes
freezing
damage, mainly expanding crack width. The forces of nature cause movement in
these cracks, especially when concrete is exposed to warm days, followed by
freezing
nights.
Replacement of the entire cracked item (driveway, stairway, etc.) is overly
costly, so
patching solutions have been developed to repair the cracks and prevent
additional
water damage. A crack repair must have enough flexibility to handle the
expansion
and contraction caused by the prevailing weather conditions so that it will
not re-crack.
A flexible sealant, bridging the crack, and handling this movement is one
common
repair method. However, while the repair has flexibility, its appearance has
no
camouflaging effect when installed in exposed aggregate. This is due to the
aggregate's distinct surface.
Accordingly, it is an object of an embodiment of the present invention to
provide a
method for repairing a crack in an aggregate surface and camouflaging the
repaired
area.
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It is a further object of an embodiment of the present invention to provide a
camouflaging product for use in repairing a crack in an aggregate surface.
Other objects of the invention will be apparent from the description that
follows.
SUMMARY OF THE INVENTION
The invention consists of a product for use in repairing a crack in an exposed
aggregate surface comprising a base sealant and an elongated flexible member
spotted with random droplets of sealant material to reproduce the look of the
exposed
aggregate surface and a method of using same for repairing the crack.
According to the preferred embodiment of the invention there is provided a kit
for
repairing a crack in an exposed aggregate concrete surface comprising a base
sealant
for filling the crack and an elongated flexible member corresponding in color
to the
color of said base sealant. The elongated flexible member being coated with
droplets
corresponding in size and color to aggregate in the exposed aggregate concrete
surface.
In another embodiment of the invention, there is provided a method for
repairing a
crack in an exposed aggregate concrete surface comprising grinding a groove in
the
aggregate along the length of the crack and filling the groove with a
camouflaged filler.
The camouflaged filler comprises a base sealant and an elongated member coated
with droplets of sealant. The base sealant is injected into said groove and
then a pre-
selected length of elongated member is inserted into the base sealant leaving
the
droplets visible.
The foregoing was intended as a broad summary only and of only some of the
aspects
of the invention. It was not intended to define the limits or requirements of
the
invention. Other aspects of the invention will be appreciated by reference to
the
detailed description of the preferred embodiment and to the claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the
following description in which reference is made to the appended drawings and
wherein:
Fig. 1 is a perspective view of a section of aggregate having a crack;
Fig. 2 is a perspective view of the section of aggregate shown in Fig. 1, with
the
crack repaired;
Fig. 3 is perspective view of a portion of the repaired aggregate showing the
various layers of repair material according to the preferred embodiment of the
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exposed aggregate is a mixture of concrete with a consistent aggregate size
and
colour. When the aggregate is poured in place, the upper surface layer,
typically about
2 cm thick, is retarded from curing. Once the un-retarded concrete has cured,
the
retarded upper surface layer is removed by spraying it with water. This
exposes the
surface of the concrete slab, revealing the various aggregate set in place in
the cured
concrete, hence the term exposed aggregate.
A slab of exposed aggregate 10 is shown in Fig. 1 having a large crack 12
extending
therethrough. In order to repair the crack 12, a grinder or the like,
preferably with a
diamond or carbide blade, is used to grind a groove 14 along the length of the
crack,
preferably with the crack centered along the base of the groove 14. Groove 14
works
to smooth out potentially jagged switchbacks of the crack and to provide a
uniform
depression within which repair material can be placed as discussed in more
detail
below. Preferably, the groove 14 forms a depression no more than 3/8 of an
inch deep
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to allow proper curing of the repair material. The width of the groove will
depend on
the displacement of the crack to be repaired.
As shown in Fig. 2, after the groove 14 has been grinded the length of the
exposed
surface of crack 12 it is filled according to the present invention to seal
the crack with a
camouflaged filler material 15. This will be described in more detail with
reference to
Fig. 3.
Camouflaged filler material 16 is preferably comprised of a flexible base
sealant 18,
and a flexible spine 20 having a plurality of randomly placed rubber droplets
22 affixed
thereto. Spine 20 is preferably an elongated flexible member having branching
elements 24 extending therefrom. Spine 20 is preferably formed by placing
sealant
material in a pre-shaped mold and allowing it to dry. It is also contemplated
that the
spine could be formed of a strip of material such as a string or the like that
is coated
with the sealant material. Preferably, the flexible member has branching
elements
providing a surface to which the rubber droplets 22 can be affixed. For
example, a
strip of carpet matting (the mat matrix used to hook rugs as in hobby type rug
making)
cut to provide the elongated member with branching elements has been found to
work
well, however it is contemplated that other materials would be suitable
provided that
they are flexible and capable of bonding with the rubber droplets 22.
Similarly, other
shapes for the spine are contemplated, provided that it is elongated and
sufficiently
wide to provide a surface upon which droplets can be placed.
After the spine 20 has properly cured it is then coated along one side with
droplets 22
of rubber sealant randomly distributed along its length. The colour of the
droplets can
be varied so as to blend with different aggregate colours. Preferably the
sealant and
droplets are made of a urethane caulking, which can be varied in colour and
viscosity.
The length and width and colour of the spine 20 can be varied for different
applications. Similarly, the colour, size and number of droplets can be varied
to
correspond to different aggregate types.
After grinding the groove 14, it is filled with a base sealant matching the
colour of the
concrete. A length of spine 20 the colour of the base sealant and with
droplets 22
matching the colour of the aggregate is selected and cut to correspond to the
length of
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the groove. The spine is then carefully inserted into the base sealant 18
leaving the
droplets 24 exposed along the top surface. By matching the spine 20 to the
base
sealant 18, the spine 20 essentially becomes invisible when inserted into the
base
sealant 18 leaving the droplets 22 visible along the top.
The droplet coated spines could be sold as a unit and could come in a variety
of
colours and sizes. It is contemplated that the product of the invention could
be sold as
an aggregate repair kit that would include base sealant of a given colour and
a length
of spine the colour of the base sealant that is coated with droplets, the
droplets being a
different colour than the spine and base sealant. Each kit could include
multiple
variations of base sealant having different colours so as to enable proper
matching to
the exposed aggregate concrete to be repaired. Similarly, multiple variations
of spine
- different lengths, widths and colours, could be included in the kit, the
various spines
being pre-coated with droplets. The droplets could also vary in size and
colour so as
to provide suitable options for repair purposes.
The camouflage filler material of the present invention provides a durable,
camouflaging repair to a crack in exposed aggregate. It is a long lasting
solution, the
rubber characteristics of the sealant and rubber droplets being able to handle
heavy
vehicular traffic and acting to prevent further water ingress into the crack
and the
resulting worsening such water ingress may cause. It is a quick and easy
repair
solution that can be used on any exposed surface regardless of its orientation
be it
horizontal or vertical surfaces or some angle in between.
It will be appreciated by those skilled in the art that the preferred and
alternative
embodiments have been described in some detail but that certain modifications
may
be practiced without departing from the principles of the invention.
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